89 files changed, 1925 insertions, 1262 deletions
diff --git a/Cargo.lock b/Cargo.lock
index cfb081e18..56fb4aad3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -32,7 +32,7 @@ name = "atty"
 version = "0.2.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -50,7 +50,7 @@ dependencies = [
 "autocfg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "backtrace-sys 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
 "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-demangle 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -61,7 +61,7 @@ version = "0.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cc 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -111,14 +111,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "cargo_metadata"
-version = "0.6.4"
+version = "0.7.0"
-source = "git+https://github.com/oli-obk/cargo_metadata.git?rev=f73e27b24e#f73e27b24e92cd9b520a78497cd1017b70a6c99a"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -156,6 +156,17 @@ dependencies = [
 ]
 [[package]]
+name = "clicolors-control"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "cloudabi"
 version = "0.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -164,6 +175,23 @@ dependencies = [
 ]
 [[package]]
+name = "console"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "atty 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clicolors-control 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "encode_unicode 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "termios 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "crossbeam-channel"
 version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -220,7 +248,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -260,6 +288,11 @@ dependencies = [
 ]
 [[package]]
+name = "encode_unicode"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+[[package]]
 name = "error-chain"
 version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -283,7 +316,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -337,10 +370,10 @@ version = "0.1.0"
 dependencies = [
 "crossbeam-channel 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "languageserver-types 0.53.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lsp-types 0.54.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -394,6 +427,20 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
+name = "insta"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "console 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "itertools"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -412,28 +459,13 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
-name = "languageserver-types"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-derive 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
- "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "url_serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-[[package]]
 name = "lazy_static"
 version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "libc"
-version = "0.2.46"
+version = "0.2.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
@@ -454,6 +486,21 @@ dependencies = [
 ]
 [[package]]
+name = "lsp-types"
+version = "0.54.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-derive 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "url_serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "maplit"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -469,7 +516,7 @@ version = "2.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -478,7 +525,7 @@ name = "memmap"
 version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -500,7 +547,7 @@ dependencies = [
 "num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -521,7 +568,7 @@ name = "num_cpus"
 version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -546,7 +593,7 @@ name = "parking_lot_core"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -584,7 +631,7 @@ dependencies = [
 "pest_meta 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -660,7 +707,7 @@ dependencies = [
 "ra_syntax 0.1.0",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (git+https://github.com/matklad/salsa?branch=panic-hooks)",
+ "salsa 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 ]
@@ -679,7 +726,7 @@ dependencies = [
 "ra_syntax 0.1.0",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (git+https://github.com/matklad/salsa?branch=panic-hooks)",
+ "salsa 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 ]
@@ -688,6 +735,7 @@ name = "ra_ide_api"
 version = "0.1.0"
 dependencies = [
 "fst 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "insta 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -699,7 +747,7 @@ dependencies = [
 "rayon 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "salsa 0.9.1 (git+https://github.com/matklad/salsa?branch=panic-hooks)",
+ "salsa 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 "unicase 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -708,6 +756,7 @@ dependencies = [
 name = "ra_ide_api_light"
 version = "0.1.0"
 dependencies = [
+ "insta 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "proptest 0.8.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -722,7 +771,7 @@ dependencies = [
 name = "ra_lsp_server"
 version = "0.1.0"
 dependencies = [
- "cargo_metadata 0.6.4 (git+https://github.com/oli-obk/cargo_metadata.git?rev=f73e27b24e)",
+ "cargo_metadata 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "crossbeam-channel 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "drop_bomb 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -730,8 +779,8 @@ dependencies = [
 "flexi_logger 0.10.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "gen_lsp_server 0.1.0",
 "im 12.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "languageserver-types 0.53.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lsp-types 0.54.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_arena 0.1.0",
 "ra_ide_api 0.1.0",
@@ -742,7 +791,7 @@ dependencies = [
 "relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "tempfile 3.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 "thread_worker 0.1.0",
@@ -760,7 +809,7 @@ dependencies = [
 "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "ra_text_edit 0.1.0",
- "rowan 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rowan 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "smol_str 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)",
 "test_utils 0.1.0",
 "text_unit 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -798,7 +847,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_core 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -809,7 +858,7 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "autocfg 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -865,7 +914,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand_core 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -905,7 +954,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -975,7 +1024,7 @@ dependencies = [
 [[package]]
 name = "rowan"
-version = "0.3.0"
+version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1022,8 +1071,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "salsa"
-version = "0.9.1"
+version = "0.9.2"
-source = "git+https://github.com/matklad/salsa?branch=panic-hooks#88313c80302c831ebc7601912ab3f11ad37e6bc2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "derive-new 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1076,12 +1125,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
 name = "serde_json"
-version = "1.0.34"
+version = "1.0.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1141,7 +1190,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "syn"
-version = "0.15.24"
+version = "0.15.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1156,7 +1205,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "proc-macro2 0.4.24 (registry+https://github.com/rust-lang/crates.io-index)",
 "quote 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)",
 "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1166,7 +1215,7 @@ version = "3.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
 "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "rand 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1187,7 +1236,7 @@ dependencies = [
 "pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "regex 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "slug 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
 "unic-segment 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1209,18 +1258,26 @@ name = "termion"
 version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_termios 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
+name = "termios"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+[[package]]
 name = "test_utils"
 version = "0.1.0"
 dependencies = [
 "difference 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)",
 "text_unit 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1270,7 +1327,7 @@ name = "time"
 version = "0.1.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 "redox_syscall 0.1.50 (registry+https://github.com/rust-lang/crates.io-index)",
 "winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -1433,7 +1490,7 @@ name = "wait-timeout"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 [[package]]
@@ -1489,12 +1546,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum block-buffer 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a076c298b9ecdb530ed9d967e74a6027d6a7478924520acddcddc24c1c8ab3ab"
 "checksum byte-tools 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "560c32574a12a89ecd91f5e742165893f86e3ab98d21f8ea548658eb9eef5f40"
 "checksum byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "94f88df23a25417badc922ab0f5716cc1330e87f71ddd9203b3a3ccd9cedf75d"
-"checksum cargo_metadata 0.6.4 (git+https://github.com/oli-obk/cargo_metadata.git?rev=f73e27b24e)" = "<none>"
+"checksum cargo_metadata 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "95932a7ed5f2308fc00a46d2aa8eb1b06b402c896c2df424916ee730ba610c2e"
 "checksum cc 1.0.28 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4a8b715cb4597106ea87c7c84b2f1d452c7492033765df7f32651e66fcf749"
 "checksum cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "082bb9b28e00d3c9d39cc03e64ce4cea0f1bb9b3fde493f0cbc008472d22bdf4"
 "checksum chrono 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "45912881121cb26fad7c38c17ba7daa18764771836b34fab7d3fbd93ed633878"
 "checksum clap 2.32.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b957d88f4b6a63b9d70d5f454ac8011819c6efa7727858f458ab71c756ce2d3e"
+"checksum clicolors-control 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "73abfd4c73d003a674ce5d2933fca6ce6c42480ea84a5ffe0a2dc39ed56300f9"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum console 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ecc3753530b959618f617b0cd6494526008d98687f1af5d8f9fa83fa9cdbb594"
 "checksum crossbeam-channel 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "137bc235f622ffaa0428e3854e24acb53291fc0b3ff6fb2cb75a8be6fb02f06b"
 "checksum crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f739f8c5363aca78cfb059edf753d8f0d36908c348f3d8d1503f03d8b75d9cf3"
 "checksum crossbeam-epoch 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "927121f5407de9956180ff5e936fe3cf4324279280001cd56b669d28ee7e9150"
@@ -1507,6 +1566,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum drop_bomb 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "69b26e475fd29098530e709294e94e661974c851aed42512793f120fed4e199f"
 "checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum ena 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "f56c93cc076508c549d9bb747f79aa9b4eb098be7b8cad8830c3137ef52d1e00"
+"checksum encode_unicode 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "90b2c9496c001e8cb61827acdefad780795c42264c137744cae6f7d9e3450abd"
 "checksum error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)" = "07e791d3be96241c77c43846b665ef1384606da2cd2a48730abe606a12906e02"
 "checksum failure 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "795bd83d3abeb9220f257e597aa0080a508b27533824adf336529648f6abf7e2"
 "checksum failure_derive 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "ea1063915fd7ef4309e222a5a07cf9c319fb9c7836b1f89b85458672dbb127e1"
@@ -1523,14 +1583,15 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum idna 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "38f09e0f0b1fb55fdee1f17470ad800da77af5186a1a76c026b679358b7e844e"
 "checksum im 12.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ae9c7f9bb8aee47fc16d535a705f7867a9fc83bb822e5e1043bb98e77ffeed3c"
 "checksum indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7e81a7c05f79578dbc15793d8b619db9ba32b4577003ef3af1a91c416798c58d"
+"checksum insta 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "60e94ba6dd3521d953caeed96f6ba06f4cdc9e30e398b3ee7acdd680294f87dc"
 "checksum itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b8467d9c1cebe26feb08c640139247fac215782d35371ade9a2136ed6085358"
 "checksum itoa 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1306f3464951f30e30d12373d31c79fbd52d236e5e896fd92f96ec7babbbe60b"
 "checksum join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "4dc7a5290e8c2606ce2be49f456d50f69173cb96d1541e4f66e34ac8b331a98f"
-"checksum languageserver-types 0.53.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7c01845f71b8b3b3557a8179af4434a4b2570829da12371f05272d28183a06ce"
 "checksum lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1"
-"checksum libc 0.2.46 (registry+https://github.com/rust-lang/crates.io-index)" = "023a4cd09b2ff695f9734c1934145a315594b7986398496841c7031a5a1bbdbd"
+"checksum libc 0.2.47 (registry+https://github.com/rust-lang/crates.io-index)" = "48450664a984b25d5b479554c29cc04e3150c97aa4c01da5604a2d4ed9151476"
 "checksum lock_api 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "62ebf1391f6acad60e5c8b43706dde4582df75c06698ab44511d15016bc2442c"
 "checksum log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
+"checksum lsp-types 0.54.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a252cc2be87d9329dd91c505a951996b3263582ba304870960faaae77b642183"
 "checksum maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08cbb6b4fef96b6d77bfc40ec491b1690c779e77b05cd9f07f787ed376fd4c43"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memchr 2.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "db4c41318937f6e76648f42826b1d9ade5c09cafb5aef7e351240a70f39206e9"
@@ -1573,20 +1634,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0e7790c7f1cc73d831d28dc5a7deb316a006e7848e6a7f467cdb10a0a9e0fb1c"
 "checksum remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3488ba1b9a2084d38645c4c08276a1752dcbf2c7130d74f1569681ad5d2799c5"
 "checksum ron 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d9cb28ade964585205aaca1f3d41a6297f72e1ad097b49c4bbde033ef86b38d7"
-"checksum rowan 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "4df666a130f870e6ac76fa525b0b6d984cfeee8f4cd675f2a125f0aced79c5f7"
+"checksum rowan 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "660069534501214380ab070b979f4b41e8cf3a5279ae07d0e949675efbd595bd"
 "checksum rustc-demangle 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "adacaae16d02b6ec37fdc7acfcddf365978de76d1983d3ee22afc260e1ca9619"
 "checksum rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7540fc8b0c49f096ee9c961cda096467dce8084bec6bdca2fc83895fd9b28cb8"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
 "checksum rusty-fork 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9591f190d2852720b679c21f66ad929f9f1d7bb09d1193c26167586029d8489c"
 "checksum ryu 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "eb9e9b8cde282a9fe6a42dd4681319bfb63f121b8a8ee9439c6f4107e58a46f7"
-"checksum salsa 0.9.1 (git+https://github.com/matklad/salsa?branch=panic-hooks)" = "<none>"
+"checksum salsa 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c73fd43ecb8ec5fbe64828ced981075b828109f011620d0fa1b66e9e983ceb84"
 "checksum same-file 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "8f20c4be53a8a1ff4c1f1b2bd14570d2f634628709752f0702ecdd2b3f9a5267"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum serde 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)" = "0e732ed5a5592c17d961555e3b552985baf98d50ce418b7b655f31f6ba7eb1b7"
 "checksum serde_derive 1.0.84 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d6115a3ca25c224e409185325afc16a0d5aaaabc15c42b09587d6f1ba39a5b"
-"checksum serde_json 1.0.34 (registry+https://github.com/rust-lang/crates.io-index)" = "bdf540260cfee6da923831f4776ddc495ada940c30117977c70f1313a6130545"
+"checksum serde_json 1.0.35 (registry+https://github.com/rust-lang/crates.io-index)" = "dfb1277d4d0563e4593e0b8b5d23d744d277b55d2bc0bf1c38d0d8a6589d38aa"
 "checksum sha-1 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "51b9d1f3b5de8a167ab06834a7c883bd197f2191e1dda1a22d9ccfeedbf9aded"
 "checksum slug 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "b3bc762e6a4b6c6fcaade73e77f9ebc6991b676f88bb2358bddb56560f073373"
 "checksum smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)" = "b73ea3738b47563803ef814925e69be00799a8c07420be8b996f8e98fb2336db"
@@ -1594,12 +1655,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
 "checksum superslice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b50b13d42370e0f5fc62eafdd5c2d20065eaf5458dab215ff3e20e63eea96b30"
-"checksum syn 0.15.24 (registry+https://github.com/rust-lang/crates.io-index)" = "734ecc29cd36e8123850d9bf21dfd62ef8300aaa8f879aabaa899721808be37c"
+"checksum syn 0.15.25 (registry+https://github.com/rust-lang/crates.io-index)" = "71b7693d9626935a362a3d1d4e59380800a919ebfa478d77a4f49e2a6d2c3ad5"
 "checksum synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "73687139bf99285483c96ac0add482c3776528beac1d97d444f6e91f203a2015"
 "checksum tempfile 3.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "7e91405c14320e5c79b3d148e1c86f40749a36e490642202a31689cb1a3452b2"
 "checksum tera 0.11.20 (registry+https://github.com/rust-lang/crates.io-index)" = "4b505279e19d8f7d24b1a9dc58327c9c36174b1a2c7ebdeac70792d017cb64f3"
 "checksum teraron 0.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0d89ad4617d1dec55331067fadaa041e813479e1779616f3d3ce9308bf46184e"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
+"checksum termios 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "72b620c5ea021d75a735c943269bb07d30c9b77d6ac6b236bc8b5c496ef05625"
 "checksum text_unit 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "158bb1c22b638b1da3c95a8ad9f061ea40d4d39fd0301be3a520f92efeeb189e"
 "checksum textwrap 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "307686869c93e71f94da64286f9a9524c0f308a9e1c87a583de8e9c9039ad3f6"
 "checksum thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c6b53e329000edc2b34dbe8545fd20e55a333362d0a321909685a19bd28c3f1b"
diff --git a/Cargo.toml b/Cargo.toml
index 85aaa23b9..c5155e899 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,5 +6,3 @@ incremental = true
 debug = true
 [patch.'crates-io']
-cargo_metadata = { git = "https://github.com/oli-obk/cargo_metadata.git", rev="f73e27b24e" }
-salsa = { git = "https://github.com/matklad/salsa", branch = "panic-hooks" }
diff --git a/crates/gen_lsp_server/Cargo.toml b/crates/gen_lsp_server/Cargo.toml
index a421a3e0b..041151741 100644
--- a/crates/gen_lsp_server/Cargo.toml
+++ b/crates/gen_lsp_server/Cargo.toml
@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 description = "Generic LSP server scaffold."
 [dependencies]
-languageserver-types = "0.53.1"
+lsp-types = "0.54.0"
 log = "0.4.3"
 failure = "0.1.4"
 serde_json = "1.0.34"
diff --git a/crates/gen_lsp_server/src/lib.rs b/crates/gen_lsp_server/src/lib.rs
index 16ac799ac..edbdda6c8 100644
--- a/crates/gen_lsp_server/src/lib.rs
+++ b/crates/gen_lsp_server/src/lib.rs
@@ -6,12 +6,12 @@
 //!
 //! ```no_run
 //! extern crate gen_lsp_server;
-//! extern crate languageserver_types;
+//! extern crate lsp_types;
 //! extern crate failure;
 //! extern crate crossbeam_channel;
 //!
 //! use crossbeam_channel::{Sender, Receiver};
-//! use languageserver_types::{ServerCapabilities, InitializeParams, request::{GotoDefinition, GotoDefinitionResponse}};
+//! use lsp_types::{ServerCapabilities, InitializeParams, request::{GotoDefinition, GotoDefinitionResponse}};
 //! use gen_lsp_server::{run_server, stdio_transport, handle_shutdown, RawMessage, RawResponse};
 //!
 //! fn main() -> Result<(), failure::Error> {
@@ -65,7 +65,7 @@ mod msg;
 mod stdio;
 use crossbeam_channel::{Receiver, Sender};
-use languageserver_types::{
+use lsp_types::{
    notification::{Exit, Initialized},
    request::{Initialize, Shutdown},
    InitializeParams, InitializeResult, ServerCapabilities,
diff --git a/crates/gen_lsp_server/src/msg.rs b/crates/gen_lsp_server/src/msg.rs
index 94bef374c..818111fe7 100644
--- a/crates/gen_lsp_server/src/msg.rs
+++ b/crates/gen_lsp_server/src/msg.rs
@@ -1,6 +1,6 @@
 use std::io::{BufRead, Write};
-use languageserver_types::{notification::Notification, request::Request};
+use lsp_types::{notification::Notification, request::Request};
 use serde::{Deserialize, Serialize};
 use serde_json::{from_str, from_value, to_string, to_value, Value};
 use failure::{bail, format_err};
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 2c1f94ad0..21d987688 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -6,7 +6,7 @@ authors = ["Aleksey Kladov <[email protected]>"]
 [dependencies]
 relative-path = "0.4.0"
-salsa = "0.9.1"
+salsa = "0.9.2"
 rustc-hash = "1.0"
 parking_lot = "0.7.0"
 ra_arena = { path = "../ra_arena" }
diff --git a/crates/ra_db/src/cancellation.rs b/crates/ra_db/src/cancellation.rs
index 32a268553..439080075 100644
--- a/crates/ra_db/src/cancellation.rs
+++ b/crates/ra_db/src/cancellation.rs
@@ -21,8 +21,6 @@ pub struct Canceled {
    _private: (),
 }
-pub type Cancelable<T> = Result<T, Canceled>;
 impl Canceled {
    pub(crate) fn new() -> Canceled {
        Canceled { _private: () }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 0c4dfc8c6..89113e7a6 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -10,7 +10,7 @@ use std::panic;
 use ra_syntax::{TextUnit, TextRange, SourceFile, TreeArc};
 pub use crate::{
-    cancellation::{Canceled, Cancelable},
+    cancellation::Canceled,
    syntax_ptr::LocalSyntaxPtr,
    input::{
        FilesDatabase, FileId, CrateId, SourceRoot, SourceRootId, CrateGraph, Dependency,
@@ -21,10 +21,23 @@ pub use crate::{
 };
 pub trait BaseDatabase: salsa::Database + panic::RefUnwindSafe {
-    fn check_canceled(&self) -> Cancelable<()> {
+    /// Aborts current query if there are pending changes.
-        self.salsa_runtime()
+    ///
-            .if_current_revision_is_canceled(Canceled::throw);
+    /// rust-analyzer needs to be able to answer semantic questions about the
-        Ok(())
+    /// code while the code is being modified. A common problem is that a
+    /// long-running query is being calculated when a new change arrives.
+    ///
+    /// We can't just apply the change immediately: this will cause the pending
+    /// query to see inconsistent state (it will observe an absence of
+    /// repeatable read). So what we do is we **cancel** all pending queries
+    /// before applying the change.
+    ///
+    /// We implement cancellation by panicking with a special value and catching
+    /// it on the API boundary. Salsa explicitly supports this use-case.
+    fn check_canceled(&self) {
+        if self.salsa_runtime().is_current_revision_canceled() {
+            Canceled::throw()
+        }
    }
    fn catch_canceled<F: FnOnce(&Self) -> T + panic::UnwindSafe, T>(
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index 0135e0e16..415848f09 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -8,7 +8,7 @@ authors = ["Aleksey Kladov <[email protected]>"]
 arrayvec = "0.4.10"
 log = "0.4.5"
 relative-path = "0.4.0"
-salsa = "0.9.1"
+salsa = "0.9.2"
 rustc-hash = "1.0"
 parking_lot = "0.7.0"
 ena = "0.11"
diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index bcb705c24..d87fe7049 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -1,6 +1,5 @@
 use std::sync::Arc;
-use ra_db::Cancelable;
 use ra_syntax::{
    SyntaxNode,
    ast::{self, NameOwner, StructFlavor, AstNode}
@@ -18,8 +17,8 @@ impl Struct {
        Struct { def_id }
    }
-    pub(crate) fn variant_data(&self, db: &impl HirDatabase) -> Cancelable<Arc<VariantData>> {
+    pub(crate) fn variant_data(&self, db: &impl HirDatabase) -> Arc<VariantData> {
-        Ok(db.struct_data(self.def_id)?.variant_data.clone())
+        db.struct_data(self.def_id).variant_data.clone()
    }
 }
@@ -37,16 +36,13 @@ impl StructData {
        StructData { name, variant_data }
    }
-    pub(crate) fn struct_data_query(
+    pub(crate) fn struct_data_query(db: &impl HirDatabase, def_id: DefId) -> Arc<StructData> {
-        db: &impl HirDatabase,
-        def_id: DefId,
-    ) -> Cancelable<Arc<StructData>> {
        let def_loc = def_id.loc(db);
        assert!(def_loc.kind == DefKind::Struct);
        let syntax = db.file_item(def_loc.source_item_id);
        let struct_def =
            ast::StructDef::cast(&syntax).expect("struct def should point to StructDef node");
-        Ok(Arc::new(StructData::new(struct_def)))
+        Arc::new(StructData::new(struct_def))
    }
 }
@@ -84,10 +80,7 @@ impl EnumData {
        EnumData { name, variants }
    }
-    pub(crate) fn enum_data_query(
+    pub(crate) fn enum_data_query(db: &impl HirDatabase, def_id: DefId) -> Arc<EnumData> {
-        db: &impl HirDatabase,
-        def_id: DefId,
-    ) -> Cancelable<Arc<EnumData>> {
        let def_loc = def_id.loc(db);
        assert!(def_loc.kind == DefKind::Enum);
        let syntax = db.file_item(def_loc.source_item_id);
@@ -107,7 +100,7 @@ impl EnumData {
        } else {
            Vec::new()
        };
-        Ok(Arc::new(EnumData::new(enum_def, variants)))
+        Arc::new(EnumData::new(enum_def, variants))
    }
 }
@@ -133,7 +126,7 @@ impl EnumVariantData {
    pub(crate) fn enum_variant_data_query(
        db: &impl HirDatabase,
        def_id: DefId,
-    ) -> Cancelable<Arc<EnumVariantData>> {
+    ) -> Arc<EnumVariantData> {
        let def_loc = def_id.loc(db);
        assert!(def_loc.kind == DefKind::EnumVariant);
        let syntax = db.file_item(def_loc.source_item_id);
@@ -146,10 +139,7 @@ impl EnumVariantData {
            .expect("enum variant list should have enum ancestor");
        let enum_def_id = get_def_id(db, &def_loc, enum_node, DefKind::Enum);
-        Ok(Arc::new(EnumVariantData::new(
+        Arc::new(EnumVariantData::new(variant_def, Enum::new(enum_def_id)))
-            variant_def,
-            Enum::new(enum_def_id),
-        )))
    }
 }
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 91b235594..0cf7deac9 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 use relative_path::RelativePathBuf;
-use ra_db::{CrateId, Cancelable, FileId};
+use ra_db::{CrateId, FileId};
 use ra_syntax::{ast, TreeArc, SyntaxNode};
 use crate::{
@@ -33,10 +33,10 @@ impl Crate {
    pub fn crate_id(&self) -> CrateId {
        self.crate_id
    }
-    pub fn dependencies(&self, db: &impl HirDatabase) -> Cancelable<Vec<CrateDependency>> {
+    pub fn dependencies(&self, db: &impl HirDatabase) -> Vec<CrateDependency> {
-        Ok(self.dependencies_impl(db))
+        self.dependencies_impl(db)
    }
-    pub fn root_module(&self, db: &impl HirDatabase) -> Cancelable<Option<Module>> {
+    pub fn root_module(&self, db: &impl HirDatabase) -> Option<Module> {
        self.root_module_impl(db)
    }
 }
@@ -78,12 +78,12 @@ pub enum Problem {
 impl Module {
    /// Name of this module.
-    pub fn name(&self, db: &impl HirDatabase) -> Cancelable<Option<Name>> {
+    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
        self.name_impl(db)
    }
    /// Returns a node which defines this module. That is, a file or a `mod foo {}` with items.
-    pub fn definition_source(&self, db: &impl HirDatabase) -> Cancelable<(FileId, ModuleSource)> {
+    pub fn definition_source(&self, db: &impl HirDatabase) -> (FileId, ModuleSource) {
        self.definition_source_impl(db)
    }
@@ -92,60 +92,57 @@ impl Module {
    pub fn declaration_source(
        &self,
        db: &impl HirDatabase,
-    ) -> Cancelable<Option<(FileId, TreeArc<ast::Module>)>> {
+    ) -> Option<(FileId, TreeArc<ast::Module>)> {
        self.declaration_source_impl(db)
    }
    /// Returns the crate this module is part of.
-    pub fn krate(&self, db: &impl HirDatabase) -> Cancelable<Option<Crate>> {
+    pub fn krate(&self, db: &impl HirDatabase) -> Option<Crate> {
        self.krate_impl(db)
    }
    /// Topmost parent of this module. Every module has a `crate_root`, but some
    /// might be missing `krate`. This can happen if a module's file is not included
    /// in the module tree of any target in Cargo.toml.
-    pub fn crate_root(&self, db: &impl HirDatabase) -> Cancelable<Module> {
+    pub fn crate_root(&self, db: &impl HirDatabase) -> Module {
        self.crate_root_impl(db)
    }
    /// Finds a child module with the specified name.
-    pub fn child(&self, db: &impl HirDatabase, name: &Name) -> Cancelable<Option<Module>> {
+    pub fn child(&self, db: &impl HirDatabase, name: &Name) -> Option<Module> {
        self.child_impl(db, name)
    }
    /// Iterates over all child modules.
-    pub fn children(&self, db: &impl HirDatabase) -> Cancelable<impl Iterator<Item = Module>> {
+    pub fn children(&self, db: &impl HirDatabase) -> impl Iterator<Item = Module> {
        self.children_impl(db)
    }
    /// Finds a parent module.
-    pub fn parent(&self, db: &impl HirDatabase) -> Cancelable<Option<Module>> {
+    pub fn parent(&self, db: &impl HirDatabase) -> Option<Module> {
        self.parent_impl(db)
    }
-    pub fn path_to_root(&self, db: &impl HirDatabase) -> Cancelable<Vec<Module>> {
+    pub fn path_to_root(&self, db: &impl HirDatabase) -> Vec<Module> {
        let mut res = vec![self.clone()];
        let mut curr = self.clone();
-        while let Some(next) = curr.parent(db)? {
+        while let Some(next) = curr.parent(db) {
            res.push(next.clone());
            curr = next
        }
-        Ok(res)
+        res
    }
    /// Returns a `ModuleScope`: a set of items, visible in this module.
-    pub fn scope(&self, db: &impl HirDatabase) -> Cancelable<ModuleScope> {
+    pub fn scope(&self, db: &impl HirDatabase) -> ModuleScope {
        self.scope_impl(db)
    }
-    pub fn resolve_path(&self, db: &impl HirDatabase, path: &Path) -> Cancelable<PerNs<DefId>> {
+    pub fn resolve_path(&self, db: &impl HirDatabase, path: &Path) -> PerNs<DefId> {
        self.resolve_path_impl(db, path)
    }
-    pub fn problems(
+    pub fn problems(&self, db: &impl HirDatabase) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
-        &self,
-        db: &impl HirDatabase,
-    ) -> Cancelable<Vec<(TreeArc<SyntaxNode>, Problem)>> {
        self.problems_impl(db)
    }
 }
@@ -160,7 +157,7 @@ impl StructField {
    pub fn name(&self) -> &Name {
        &self.name
    }
-    pub fn ty(&self, db: &impl HirDatabase) -> Cancelable<Option<Ty>> {
+    pub fn ty(&self, db: &impl HirDatabase) -> Option<Ty> {
        db.type_for_field(self.struct_.def_id, self.name.clone())
    }
 }
@@ -175,13 +172,12 @@ impl Struct {
        self.def_id
    }
-    pub fn name(&self, db: &impl HirDatabase) -> Cancelable<Option<Name>> {
+    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
-        Ok(db.struct_data(self.def_id)?.name.clone())
+        db.struct_data(self.def_id).name.clone()
    }
-    pub fn fields(&self, db: &impl HirDatabase) -> Cancelable<Vec<StructField>> {
+    pub fn fields(&self, db: &impl HirDatabase) -> Vec<StructField> {
-        let res = db
+        db.struct_data(self.def_id)
-            .struct_data(self.def_id)?
            .variant_data
            .fields()
            .iter()
@@ -189,15 +185,11 @@ impl Struct {
                struct_: self.clone(),
                name: it.name.clone(),
            })
-            .collect();
+            .collect()
-        Ok(res)
    }
-    pub fn source(
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::StructDef>) {
-        &self,
+        def_id_to_ast(db, self.def_id)
-        db: &impl HirDatabase,
-    ) -> Cancelable<(HirFileId, TreeArc<ast::StructDef>)> {
-        Ok(def_id_to_ast(db, self.def_id))
    }
 }
@@ -215,16 +207,16 @@ impl Enum {
        self.def_id
    }
-    pub fn name(&self, db: &impl HirDatabase) -> Cancelable<Option<Name>> {
+    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
-        Ok(db.enum_data(self.def_id)?.name.clone())
+        db.enum_data(self.def_id).name.clone()
    }
-    pub fn variants(&self, db: &impl HirDatabase) -> Cancelable<Vec<(Name, EnumVariant)>> {
+    pub fn variants(&self, db: &impl HirDatabase) -> Vec<(Name, EnumVariant)> {
-        Ok(db.enum_data(self.def_id)?.variants.clone())
+        db.enum_data(self.def_id).variants.clone()
    }
-    pub fn source(&self, db: &impl HirDatabase) -> Cancelable<(HirFileId, TreeArc<ast::EnumDef>)> {
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::EnumDef>) {
-        Ok(def_id_to_ast(db, self.def_id))
+        def_id_to_ast(db, self.def_id)
    }
 }
@@ -242,23 +234,20 @@ impl EnumVariant {
        self.def_id
    }
-    pub fn parent_enum(&self, db: &impl HirDatabase) -> Cancelable<Enum> {
+    pub fn parent_enum(&self, db: &impl HirDatabase) -> Enum {
-        Ok(db.enum_variant_data(self.def_id)?.parent_enum.clone())
+        db.enum_variant_data(self.def_id).parent_enum.clone()
    }
-    pub fn name(&self, db: &impl HirDatabase) -> Cancelable<Option<Name>> {
+    pub fn name(&self, db: &impl HirDatabase) -> Option<Name> {
-        Ok(db.enum_variant_data(self.def_id)?.name.clone())
+        db.enum_variant_data(self.def_id).name.clone()
    }
-    pub fn variant_data(&self, db: &impl HirDatabase) -> Cancelable<Arc<VariantData>> {
+    pub fn variant_data(&self, db: &impl HirDatabase) -> Arc<VariantData> {
-        Ok(db.enum_variant_data(self.def_id)?.variant_data.clone())
+        db.enum_variant_data(self.def_id).variant_data.clone()
    }
-    pub fn source(
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::EnumVariant>) {
-        &self,
+        def_id_to_ast(db, self.def_id)
-        db: &impl HirDatabase,
-    ) -> Cancelable<(HirFileId, TreeArc<ast::EnumVariant>)> {
-        Ok(def_id_to_ast(db, self.def_id))
    }
 }
@@ -305,28 +294,28 @@ impl Function {
        self.def_id
    }
-    pub fn source(&self, db: &impl HirDatabase) -> Cancelable<(HirFileId, TreeArc<ast::FnDef>)> {
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::FnDef>) {
-        Ok(def_id_to_ast(db, self.def_id))
+        def_id_to_ast(db, self.def_id)
    }
-    pub fn body_syntax_mapping(&self, db: &impl HirDatabase) -> Cancelable<Arc<BodySyntaxMapping>> {
+    pub fn body_syntax_mapping(&self, db: &impl HirDatabase) -> Arc<BodySyntaxMapping> {
        db.body_syntax_mapping(self.def_id)
    }
-    pub fn scopes(&self, db: &impl HirDatabase) -> Cancelable<ScopesWithSyntaxMapping> {
+    pub fn scopes(&self, db: &impl HirDatabase) -> ScopesWithSyntaxMapping {
-        let scopes = db.fn_scopes(self.def_id)?;
+        let scopes = db.fn_scopes(self.def_id);
-        let syntax_mapping = db.body_syntax_mapping(self.def_id)?;
+        let syntax_mapping = db.body_syntax_mapping(self.def_id);
-        Ok(ScopesWithSyntaxMapping {
+        ScopesWithSyntaxMapping {
            scopes,
            syntax_mapping,
-        })
+        }
    }
    pub fn signature(&self, db: &impl HirDatabase) -> Arc<FnSignature> {
        db.fn_signature(self.def_id)
    }
-    pub fn infer(&self, db: &impl HirDatabase) -> Cancelable<Arc<InferenceResult>> {
+    pub fn infer(&self, db: &impl HirDatabase) -> Arc<InferenceResult> {
        db.infer(self.def_id)
    }
 }
@@ -341,8 +330,8 @@ impl Const {
        Const { def_id }
    }
-    pub fn source(&self, db: &impl HirDatabase) -> Cancelable<(HirFileId, TreeArc<ast::ConstDef>)> {
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::ConstDef>) {
-        Ok(def_id_to_ast(db, self.def_id))
+        def_id_to_ast(db, self.def_id)
    }
 }
@@ -356,11 +345,8 @@ impl Static {
        Static { def_id }
    }
-    pub fn source(
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::StaticDef>) {
-        &self,
+        def_id_to_ast(db, self.def_id)
-        db: &impl HirDatabase,
-    ) -> Cancelable<(HirFileId, TreeArc<ast::StaticDef>)> {
-        Ok(def_id_to_ast(db, self.def_id))
    }
 }
@@ -374,8 +360,8 @@ impl Trait {
        Trait { def_id }
    }
-    pub fn source(&self, db: &impl HirDatabase) -> Cancelable<(HirFileId, TreeArc<ast::TraitDef>)> {
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::TraitDef>) {
-        Ok(def_id_to_ast(db, self.def_id))
+        def_id_to_ast(db, self.def_id)
    }
 }
@@ -389,7 +375,7 @@ impl Type {
        Type { def_id }
    }
-    pub fn source(&self, db: &impl HirDatabase) -> Cancelable<(HirFileId, TreeArc<ast::TypeDef>)> {
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, TreeArc<ast::TypeDef>) {
-        Ok(def_id_to_ast(db, self.def_id))
+        def_id_to_ast(db, self.def_id)
    }
 }
diff --git a/crates/ra_hir/src/code_model_impl/function.rs b/crates/ra_hir/src/code_model_impl/function.rs
index 8d6b7fc19..66d7e1713 100644
--- a/crates/ra_hir/src/code_model_impl/function.rs
+++ b/crates/ra_hir/src/code_model_impl/function.rs
@@ -2,7 +2,6 @@ mod scope;
 use std::sync::Arc;
-use ra_db::Cancelable;
 use ra_syntax::{TreeArc, ast::{self, NameOwner}};
 use crate::{
@@ -20,16 +19,16 @@ impl Function {
        Function { def_id }
    }
-    pub(crate) fn body(&self, db: &impl HirDatabase) -> Cancelable<Arc<Body>> {
+    pub(crate) fn body(&self, db: &impl HirDatabase) -> Arc<Body> {
        db.body_hir(self.def_id)
    }
-    pub(crate) fn module(&self, db: &impl HirDatabase) -> Cancelable<Module> {
+    pub(crate) fn module(&self, db: &impl HirDatabase) -> Module {
        self.def_id.module(db)
    }
    /// The containing impl block, if this is a method.
-    pub(crate) fn impl_block(&self, db: &impl HirDatabase) -> Cancelable<Option<ImplBlock>> {
+    pub(crate) fn impl_block(&self, db: &impl HirDatabase) -> Option<ImplBlock> {
        self.def_id.impl_block(db)
    }
 }
diff --git a/crates/ra_hir/src/code_model_impl/krate.rs b/crates/ra_hir/src/code_model_impl/krate.rs
index 3275eafed..8c6e34873 100644
--- a/crates/ra_hir/src/code_model_impl/krate.rs
+++ b/crates/ra_hir/src/code_model_impl/krate.rs
@@ -1,4 +1,4 @@
-use ra_db::{CrateId, Cancelable};
+use ra_db::CrateId;
 use crate::{
    HirFileId, Crate, CrateDependency, AsName, DefLoc, DefKind, Module, SourceItemId,
@@ -20,18 +20,18 @@ impl Crate {
            })
            .collect()
    }
-    pub(crate) fn root_module_impl(&self, db: &impl HirDatabase) -> Cancelable<Option<Module>> {
+    pub(crate) fn root_module_impl(&self, db: &impl HirDatabase) -> Option<Module> {
        let crate_graph = db.crate_graph();
        let file_id = crate_graph.crate_root(self.crate_id);
        let source_root_id = db.file_source_root(file_id);
        let file_id = HirFileId::from(file_id);
-        let module_tree = db.module_tree(source_root_id)?;
+        let module_tree = db.module_tree(source_root_id);
        // FIXME: teach module tree about crate roots instead of guessing
        let source = SourceItemId {
            file_id,
            item_id: None,
        };
-        let module_id = ctry!(module_tree.find_module_by_source(source));
+        let module_id = module_tree.find_module_by_source(source)?;
        let def_loc = DefLoc {
            kind: DefKind::Module,
@@ -42,6 +42,6 @@ impl Crate {
        let def_id = def_loc.id(db);
        let module = Module::new(def_id);
-        Ok(Some(module))
+        Some(module)
    }
 }
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index 775dd6709..a5c032d69 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -1,4 +1,4 @@
-use ra_db::{Cancelable, SourceRootId, FileId};
+use ra_db::{SourceRootId, FileId};
 use ra_syntax::{ast, SyntaxNode, AstNode, TreeArc};
 use crate::{
@@ -18,8 +18,8 @@ impl Module {
        db: &impl HirDatabase,
        source_root_id: SourceRootId,
        module_id: ModuleId,
-    ) -> Cancelable<Self> {
+    ) -> Self {
-        let module_tree = db.module_tree(source_root_id)?;
+        let module_tree = db.module_tree(source_root_id);
        let def_loc = DefLoc {
            kind: DefKind::Module,
            source_root_id,
@@ -27,21 +27,17 @@ impl Module {
            source_item_id: module_id.source(&module_tree),
        };
        let def_id = def_loc.id(db);
-        let module = Module::new(def_id);
+        Module::new(def_id)
-        Ok(module)
    }
-    pub(crate) fn name_impl(&self, db: &impl HirDatabase) -> Cancelable<Option<Name>> {
+    pub(crate) fn name_impl(&self, db: &impl HirDatabase) -> Option<Name> {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
-        let link = ctry!(loc.module_id.parent_link(&module_tree));
+        let link = loc.module_id.parent_link(&module_tree)?;
-        Ok(Some(link.name(&module_tree).clone()))
+        Some(link.name(&module_tree).clone())
    }
-    pub fn definition_source_impl(
+    pub fn definition_source_impl(&self, db: &impl HirDatabase) -> (FileId, ModuleSource) {
-        &self,
-        db: &impl HirDatabase,
-    ) -> Cancelable<(FileId, ModuleSource)> {
        let loc = self.def_id.loc(db);
        let file_id = loc.source_item_id.file_id.as_original_file();
        let syntax_node = db.file_item(loc.source_item_id);
@@ -51,94 +47,89 @@ impl Module {
            let module = ast::Module::cast(&syntax_node).unwrap();
            ModuleSource::Module(module.to_owned())
        };
-        Ok((file_id, module_source))
+        (file_id, module_source)
    }
    pub fn declaration_source_impl(
        &self,
        db: &impl HirDatabase,
-    ) -> Cancelable<Option<(FileId, TreeArc<ast::Module>)>> {
+    ) -> Option<(FileId, TreeArc<ast::Module>)> {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
-        let link = ctry!(loc.module_id.parent_link(&module_tree));
+        let link = loc.module_id.parent_link(&module_tree)?;
        let file_id = link
            .owner(&module_tree)
            .source(&module_tree)
            .file_id
            .as_original_file();
        let src = link.source(&module_tree, db);
-        Ok(Some((file_id, src)))
+        Some((file_id, src))
    }
-    pub(crate) fn krate_impl(&self, db: &impl HirDatabase) -> Cancelable<Option<Crate>> {
+    pub(crate) fn krate_impl(&self, db: &impl HirDatabase) -> Option<Crate> {
-        let root = self.crate_root(db)?;
+        let root = self.crate_root(db);
        let loc = root.def_id.loc(db);
        let file_id = loc.source_item_id.file_id.as_original_file();
        let crate_graph = db.crate_graph();
-        let crate_id = ctry!(crate_graph.crate_id_for_crate_root(file_id));
+        let crate_id = crate_graph.crate_id_for_crate_root(file_id)?;
-        Ok(Some(Crate::new(crate_id)))
+        Some(Crate::new(crate_id))
    }
-    pub(crate) fn crate_root_impl(&self, db: &impl HirDatabase) -> Cancelable<Module> {
+    pub(crate) fn crate_root_impl(&self, db: &impl HirDatabase) -> Module {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
        let module_id = loc.module_id.crate_root(&module_tree);
        Module::from_module_id(db, loc.source_root_id, module_id)
    }
    /// Finds a child module with the specified name.
-    pub fn child_impl(&self, db: &impl HirDatabase, name: &Name) -> Cancelable<Option<Module>> {
+    pub fn child_impl(&self, db: &impl HirDatabase, name: &Name) -> Option<Module> {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
-        let child_id = ctry!(loc.module_id.child(&module_tree, name));
+        let child_id = loc.module_id.child(&module_tree, name)?;
-        Module::from_module_id(db, loc.source_root_id, child_id).map(Some)
+        Some(Module::from_module_id(db, loc.source_root_id, child_id))
    }
    /// Iterates over all child modules.
-    pub fn children_impl(&self, db: &impl HirDatabase) -> Cancelable<impl Iterator<Item = Module>> {
+    pub fn children_impl(&self, db: &impl HirDatabase) -> impl Iterator<Item = Module> {
        // FIXME this should be implementable without collecting into a vec, but
        // it's kind of hard since the iterator needs to keep a reference to the
        // module tree.
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
        let children = loc
            .module_id
            .children(&module_tree)
            .map(|(_, module_id)| Module::from_module_id(db, loc.source_root_id, module_id))
-            .collect::<Cancelable<Vec<_>>>()?;
+            .collect::<Vec<_>>();
-        Ok(children.into_iter())
+        children.into_iter()
    }
-    pub fn parent_impl(&self, db: &impl HirDatabase) -> Cancelable<Option<Module>> {
+    pub fn parent_impl(&self, db: &impl HirDatabase) -> Option<Module> {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
-        let parent_id = ctry!(loc.module_id.parent(&module_tree));
+        let parent_id = loc.module_id.parent(&module_tree)?;
-        Module::from_module_id(db, loc.source_root_id, parent_id).map(Some)
+        Some(Module::from_module_id(db, loc.source_root_id, parent_id))
    }
    /// Returns a `ModuleScope`: a set of items, visible in this module.
-    pub fn scope_impl(&self, db: &impl HirDatabase) -> Cancelable<ModuleScope> {
+    pub fn scope_impl(&self, db: &impl HirDatabase) -> ModuleScope {
        let loc = self.def_id.loc(db);
-        let item_map = db.item_map(loc.source_root_id)?;
+        let item_map = db.item_map(loc.source_root_id);
-        let res = item_map.per_module[&loc.module_id].clone();
+        item_map.per_module[&loc.module_id].clone()
-        Ok(res)
    }
-    pub fn resolve_path_impl(
+    pub fn resolve_path_impl(&self, db: &impl HirDatabase, path: &Path) -> PerNs<DefId> {
-        &self,
-        db: &impl HirDatabase,
-        path: &Path,
-    ) -> Cancelable<PerNs<DefId>> {
        let mut curr_per_ns = PerNs::types(
            match path.kind {
-                PathKind::Crate => self.crate_root(db)?,
+                PathKind::Crate => self.crate_root(db),
                PathKind::Self_ | PathKind::Plain => self.clone(),
                PathKind::Super => {
-                    if let Some(p) = self.parent(db)? {
+                    if let Some(p) = self.parent(db) {
                        p
                    } else {
-                        return Ok(PerNs::none());
+                        return PerNs::none();
                    }
                }
            }
@@ -150,47 +141,44 @@ impl Module {
            let curr = if let Some(r) = curr_per_ns.as_ref().take_types() {
                r
            } else {
-                return Ok(PerNs::none());
+                return PerNs::none();
            };
-            let module = match curr.resolve(db)? {
+            let module = match curr.resolve(db) {
                Def::Module(it) => it,
                Def::Enum(e) => {
                    if segments.len() == idx + 1 {
                        // enum variant
                        let matching_variant =
-                            e.variants(db)?.into_iter().find(|(n, _variant)| n == name);
+                            e.variants(db).into_iter().find(|(n, _variant)| n == name);
                        if let Some((_n, variant)) = matching_variant {
-                            return Ok(PerNs::both(variant.def_id(), e.def_id()));
+                            return PerNs::both(variant.def_id(), e.def_id());
                        } else {
-                            return Ok(PerNs::none());
+                            return PerNs::none();
                        }
                    } else if segments.len() == idx {
                        // enum
-                        return Ok(PerNs::types(e.def_id()));
+                        return PerNs::types(e.def_id());
                    } else {
                        // malformed enum?
-                        return Ok(PerNs::none());
+                        return PerNs::none();
                    }
                }
-                _ => return Ok(PerNs::none()),
+                _ => return PerNs::none(),
            };
-            let scope = module.scope(db)?;
+            let scope = module.scope(db);
            curr_per_ns = if let Some(r) = scope.get(&name) {
                r.def_id
            } else {
-                return Ok(PerNs::none());
+                return PerNs::none();
            };
        }
-        Ok(curr_per_ns)
+        curr_per_ns
    }
-    pub fn problems_impl(
+    pub fn problems_impl(&self, db: &impl HirDatabase) -> Vec<(TreeArc<SyntaxNode>, Problem)> {
-        &self,
-        db: &impl HirDatabase,
-    ) -> Cancelable<Vec<(TreeArc<SyntaxNode>, Problem)>> {
        let loc = self.def_id.loc(db);
-        let module_tree = db.module_tree(loc.source_root_id)?;
+        let module_tree = db.module_tree(loc.source_root_id);
-        Ok(loc.module_id.problems(&module_tree, db))
+        loc.module_id.problems(&module_tree, db)
    }
 }
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index fd6336dd8..0a0994f5f 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 use ra_syntax::{SyntaxNode, TreeArc, SourceFile};
-use ra_db::{SourceRootId, LocationIntener, SyntaxDatabase, Cancelable};
+use ra_db::{SourceRootId, LocationIntener, SyntaxDatabase};
 use crate::{
    DefLoc, DefId, MacroCallLoc, MacroCallId, Name, HirFileId,
@@ -32,37 +32,37 @@ pub trait HirDatabase: SyntaxDatabase
        use fn crate::macros::expand_macro_invocation;
    }
-    fn fn_scopes(def_id: DefId) -> Cancelable<Arc<FnScopes>> {
+    fn fn_scopes(def_id: DefId) -> Arc<FnScopes> {
        type FnScopesQuery;
        use fn query_definitions::fn_scopes;
    }
-    fn struct_data(def_id: DefId) -> Cancelable<Arc<StructData>> {
+    fn struct_data(def_id: DefId) -> Arc<StructData> {
        type StructDataQuery;
        use fn crate::adt::StructData::struct_data_query;
    }
-    fn enum_data(def_id: DefId) -> Cancelable<Arc<EnumData>> {
+    fn enum_data(def_id: DefId) -> Arc<EnumData> {
        type EnumDataQuery;
        use fn crate::adt::EnumData::enum_data_query;
    }
-    fn enum_variant_data(def_id: DefId) -> Cancelable<Arc<EnumVariantData>> {
+    fn enum_variant_data(def_id: DefId) -> Arc<EnumVariantData> {
        type EnumVariantDataQuery;
        use fn crate::adt::EnumVariantData::enum_variant_data_query;
    }
-    fn infer(def_id: DefId) -> Cancelable<Arc<InferenceResult>> {
+    fn infer(def_id: DefId) -> Arc<InferenceResult> {
        type InferQuery;
        use fn crate::ty::infer;
    }
-    fn type_for_def(def_id: DefId) -> Cancelable<Ty> {
+    fn type_for_def(def_id: DefId) -> Ty {
        type TypeForDefQuery;
        use fn crate::ty::type_for_def;
    }
-    fn type_for_field(def_id: DefId, field: Name) -> Cancelable<Option<Ty>> {
+    fn type_for_field(def_id: DefId, field: Name) -> Option<Ty> {
        type TypeForFieldQuery;
        use fn crate::ty::type_for_field;
    }
@@ -77,42 +77,42 @@ pub trait HirDatabase: SyntaxDatabase
        use fn query_definitions::file_item;
    }
-    fn submodules(source: SourceItemId) -> Cancelable<Arc<Vec<crate::module_tree::Submodule>>> {
+    fn submodules(source: SourceItemId) -> Arc<Vec<crate::module_tree::Submodule>> {
        type SubmodulesQuery;
        use fn crate::module_tree::Submodule::submodules_query;
    }
-    fn input_module_items(source_root_id: SourceRootId, module_id: ModuleId) -> Cancelable<Arc<InputModuleItems>> {
+    fn input_module_items(source_root_id: SourceRootId, module_id: ModuleId) -> Arc<InputModuleItems> {
        type InputModuleItemsQuery;
        use fn query_definitions::input_module_items;
    }
-    fn item_map(source_root_id: SourceRootId) -> Cancelable<Arc<ItemMap>> {
+    fn item_map(source_root_id: SourceRootId) -> Arc<ItemMap> {
        type ItemMapQuery;
        use fn query_definitions::item_map;
    }
-    fn module_tree(source_root_id: SourceRootId) -> Cancelable<Arc<ModuleTree>> {
+    fn module_tree(source_root_id: SourceRootId) -> Arc<ModuleTree> {
        type ModuleTreeQuery;
        use fn crate::module_tree::ModuleTree::module_tree_query;
    }
-    fn impls_in_module(source_root_id: SourceRootId, module_id: ModuleId) -> Cancelable<Arc<ModuleImplBlocks>> {
+    fn impls_in_module(source_root_id: SourceRootId, module_id: ModuleId) -> Arc<ModuleImplBlocks> {
        type ImplsInModuleQuery;
        use fn crate::impl_block::impls_in_module;
    }
-    fn impls_in_crate(krate: Crate) -> Cancelable<Arc<CrateImplBlocks>> {
+    fn impls_in_crate(krate: Crate) -> Arc<CrateImplBlocks> {
        type ImplsInCrateQuery;
        use fn crate::ty::method_resolution::CrateImplBlocks::impls_in_crate_query;
    }
-    fn body_hir(def_id: DefId) -> Cancelable<Arc<crate::expr::Body>> {
+    fn body_hir(def_id: DefId) -> Arc<crate::expr::Body> {
        type BodyHirQuery;
        use fn crate::expr::body_hir;
    }
-    fn body_syntax_mapping(def_id: DefId) -> Cancelable<Arc<crate::expr::BodySyntaxMapping>> {
+    fn body_syntax_mapping(def_id: DefId) -> Arc<crate::expr::BodySyntaxMapping> {
        type BodySyntaxMappingQuery;
        use fn crate::expr::body_syntax_mapping;
    }
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index f0936e9f3..663338844 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -4,10 +4,11 @@ use std::sync::Arc;
 use rustc_hash::FxHashMap;
 use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
-use ra_db::{LocalSyntaxPtr, Cancelable};
+use ra_db::LocalSyntaxPtr;
-use ra_syntax::ast::{self, AstNode, LoopBodyOwner, ArgListOwner, NameOwner};
+use ra_syntax::ast::{self, AstNode, LoopBodyOwner, ArgListOwner, NameOwner, LiteralFlavor};
 use crate::{Path, type_ref::{Mutability, TypeRef}, Name, HirDatabase, DefId, Def, name::AsName};
+use crate::ty::primitive::{UintTy, UncertainIntTy, UncertainFloatTy};
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct ExprId(RawId);
@@ -104,6 +105,16 @@ impl BodySyntaxMapping {
 }
 #[derive(Debug, Clone, Eq, PartialEq)]
+pub enum Literal {
+    String(String),
+    ByteString(Vec<u8>),
+    Char(char),
+    Bool(bool),
+    Int(u64, UncertainIntTy),
+    Float(u64, UncertainFloatTy), // FIXME: f64 is not Eq
+}
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub enum Expr {
    /// This is produced if syntax tree does not have a required expression piece.
    Missing,
@@ -171,7 +182,7 @@ pub enum Expr {
    },
    UnaryOp {
        expr: ExprId,
-        op: Option<UnaryOp>,
+        op: UnaryOp,
    },
    BinaryOp {
        lhs: ExprId,
@@ -186,6 +197,7 @@ pub enum Expr {
    Tuple {
        exprs: Vec<ExprId>,
    },
+    Literal(Literal),
 }
 pub use ra_syntax::ast::PrefixOp as UnaryOp;
@@ -305,6 +317,7 @@ impl Expr {
                    f(*expr);
                }
            }
+            Expr::Literal(_) => {}
        }
    }
 }
@@ -343,8 +356,8 @@ impl Pat {
 // Queries
-pub(crate) fn body_hir(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<Body>> {
+pub(crate) fn body_hir(db: &impl HirDatabase, def_id: DefId) -> Arc<Body> {
-    Ok(Arc::clone(&body_syntax_mapping(db, def_id)?.body))
+    Arc::clone(&body_syntax_mapping(db, def_id).body)
 }
 struct ExprCollector {
@@ -599,8 +612,11 @@ impl ExprCollector {
            }
            ast::ExprKind::PrefixExpr(e) => {
                let expr = self.collect_expr_opt(e.expr());
-                let op = e.op();
+                if let Some(op) = e.op() {
-                self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
+                    self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
+                } else {
+                    self.alloc_expr(Expr::Missing, syntax_ptr)
+                }
            }
            ast::ExprKind::LambdaExpr(e) => {
                let mut args = Vec::new();
@@ -633,13 +649,50 @@ impl ExprCollector {
                let exprs = e.exprs().map(|expr| self.collect_expr(expr)).collect();
                self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
            }
+            ast::ExprKind::Literal(e) => {
+                let child = if let Some(child) = e.literal_expr() {
+                    child
+                } else {
+                    return self.alloc_expr(Expr::Missing, syntax_ptr);
+                };
+                let lit = match child.flavor() {
+                    LiteralFlavor::IntNumber { suffix } => {
+                        let known_name = suffix
+                            .map(|s| Name::new(s))
+                            .and_then(|name| UncertainIntTy::from_name(&name));
+                        Literal::Int(
+                            Default::default(),
+                            known_name.unwrap_or(UncertainIntTy::Unknown),
+                        )
+                    }
+                    LiteralFlavor::FloatNumber { suffix } => {
+                        let known_name = suffix
+                            .map(|s| Name::new(s))
+                            .and_then(|name| UncertainFloatTy::from_name(&name));
+                        Literal::Float(
+                            Default::default(),
+                            known_name.unwrap_or(UncertainFloatTy::Unknown),
+                        )
+                    }
+                    LiteralFlavor::ByteString => Literal::ByteString(Default::default()),
+                    LiteralFlavor::String => Literal::String(Default::default()),
+                    LiteralFlavor::Byte => {
+                        Literal::Int(Default::default(), UncertainIntTy::Unsigned(UintTy::U8))
+                    }
+                    LiteralFlavor::Bool => Literal::Bool(Default::default()),
+                    LiteralFlavor::Char => Literal::Char(Default::default()),
+                };
+                self.alloc_expr(Expr::Literal(lit), syntax_ptr)
+            }
            // TODO implement HIR for these:
            ast::ExprKind::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
            ast::ExprKind::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
            ast::ExprKind::ArrayExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
            ast::ExprKind::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::ExprKind::Literal(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
        }
    }
@@ -776,17 +829,14 @@ pub(crate) fn collect_fn_body_syntax(node: &ast::FnDef) -> BodySyntaxMapping {
    collector.into_body_syntax_mapping(params, body)
 }
-pub(crate) fn body_syntax_mapping(
+pub(crate) fn body_syntax_mapping(db: &impl HirDatabase, def_id: DefId) -> Arc<BodySyntaxMapping> {
-    db: &impl HirDatabase,
+    let def = def_id.resolve(db);
-    def_id: DefId,
-) -> Cancelable<Arc<BodySyntaxMapping>> {
-    let def = def_id.resolve(db)?;
    let body_syntax_mapping = match def {
-        Def::Function(f) => collect_fn_body_syntax(&f.source(db)?.1),
+        Def::Function(f) => collect_fn_body_syntax(&f.source(db).1),
        // TODO: consts, etc.
        _ => panic!("Trying to get body for item type without body"),
    };
-    Ok(Arc::new(body_syntax_mapping))
+    Arc::new(body_syntax_mapping)
 }
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 316896dce..0d8e67547 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -1,4 +1,4 @@
-use ra_db::{SourceRootId, LocationIntener, Cancelable, FileId};
+use ra_db::{SourceRootId, LocationIntener, FileId};
 use ra_syntax::{TreeArc, SyntaxKind, SyntaxNode, SourceFile, AstNode, ast};
 use ra_arena::{Arena, RawId, impl_arena_id};
@@ -159,11 +159,11 @@ impl DefId {
        db.as_ref().id2loc(self)
    }
-    pub fn resolve(self, db: &impl HirDatabase) -> Cancelable<Def> {
+    pub fn resolve(self, db: &impl HirDatabase) -> Def {
        let loc = self.loc(db);
-        let res = match loc.kind {
+        match loc.kind {
            DefKind::Module => {
-                let module = Module::from_module_id(db, loc.source_root_id, loc.module_id)?;
+                let module = Module::from_module_id(db, loc.source_root_id, loc.module_id);
                Def::Module(module)
            }
            DefKind::Function => {
@@ -195,8 +195,7 @@ impl DefId {
            DefKind::StructCtor => Def::Item,
            DefKind::Item => Def::Item,
-        };
+        }
-        Ok(res)
    }
    pub(crate) fn source(self, db: &impl HirDatabase) -> (HirFileId, TreeArc<SyntaxNode>) {
@@ -206,21 +205,21 @@ impl DefId {
    }
    /// For a module, returns that module; for any other def, returns the containing module.
-    pub fn module(self, db: &impl HirDatabase) -> Cancelable<Module> {
+    pub fn module(self, db: &impl HirDatabase) -> Module {
        let loc = self.loc(db);
        Module::from_module_id(db, loc.source_root_id, loc.module_id)
    }
    /// Returns the containing crate.
-    pub fn krate(&self, db: &impl HirDatabase) -> Cancelable<Option<Crate>> {
+    pub fn krate(&self, db: &impl HirDatabase) -> Option<Crate> {
-        Ok(self.module(db)?.krate(db)?)
+        self.module(db).krate(db)
    }
    /// Returns the containing impl block, if this is an impl item.
-    pub fn impl_block(self, db: &impl HirDatabase) -> Cancelable<Option<ImplBlock>> {
+    pub fn impl_block(self, db: &impl HirDatabase) -> Option<ImplBlock> {
        let loc = self.loc(db);
-        let module_impls = db.impls_in_module(loc.source_root_id, loc.module_id)?;
+        let module_impls = db.impls_in_module(loc.source_root_id, loc.module_id);
-        Ok(ImplBlock::containing(module_impls, self))
+        ImplBlock::containing(module_impls, self)
    }
 }
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index d0b086308..ab996a12c 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -3,7 +3,7 @@ use rustc_hash::FxHashMap;
 use ra_arena::{Arena, RawId, impl_arena_id};
 use ra_syntax::ast::{self, AstNode};
-use ra_db::{LocationIntener, Cancelable, SourceRootId};
+use ra_db::{LocationIntener, SourceRootId};
 use crate::{
    DefId, DefLoc, DefKind, SourceItemId, SourceFileItems,
@@ -166,8 +166,8 @@ impl ModuleImplBlocks {
        }
    }
-    fn collect(&mut self, db: &impl HirDatabase, module: Module) -> Cancelable<()> {
+    fn collect(&mut self, db: &impl HirDatabase, module: Module) {
-        let (file_id, module_source) = module.definition_source(db)?;
+        let (file_id, module_source) = module.definition_source(db);
        let node = match &module_source {
            ModuleSource::SourceFile(node) => node.syntax(),
            ModuleSource::Module(node) => node
@@ -185,8 +185,6 @@ impl ModuleImplBlocks {
                self.impls_by_def.insert(impl_item.def_id(), id);
            }
        }
-        Ok(())
    }
 }
@@ -194,9 +192,9 @@ pub(crate) fn impls_in_module(
    db: &impl HirDatabase,
    source_root_id: SourceRootId,
    module_id: ModuleId,
-) -> Cancelable<Arc<ModuleImplBlocks>> {
+) -> Arc<ModuleImplBlocks> {
    let mut result = ModuleImplBlocks::new();
-    let module = Module::from_module_id(db, source_root_id, module_id)?;
+    let module = Module::from_module_id(db, source_root_id, module_id);
-    result.collect(db, module)?;
+    result.collect(db, module);
-    Ok(Arc::new(result))
+    Arc::new(result)
 }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 45dda4f7f..ef7d049ee 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -5,15 +5,6 @@
 //! to a particular crate instance. That is, it has cfg flags and features
 //! applied. So, the relation between syntax and HIR is many-to-one.
-macro_rules! ctry {
-    ($expr:expr) => {
-        match $expr {
-            None => return Ok(None),
-            Some(it) => it,
-        }
-    };
-}
 pub mod db;
 #[cfg(test)]
 mod mock;
diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index 67823e970..0256d7996 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 use rustc_hash::{FxHashMap, FxHashSet};
 use arrayvec::ArrayVec;
 use relative_path::RelativePathBuf;
-use ra_db::{FileId, SourceRootId, Cancelable, SourceRoot};
+use ra_db::{FileId, SourceRootId, SourceRoot};
 use ra_syntax::{
    SyntaxNode, TreeArc,
    algo::generate,
@@ -41,8 +41,8 @@ impl Submodule {
    pub(crate) fn submodules_query(
        db: &impl HirDatabase,
        source: SourceItemId,
-    ) -> Cancelable<Arc<Vec<Submodule>>> {
+    ) -> Arc<Vec<Submodule>> {
-        db.check_canceled()?;
+        db.check_canceled();
        let file_id = source.file_id;
        let file_items = db.file_items(file_id);
        let module_source = ModuleSource::from_source_item_id(db, source);
@@ -54,7 +54,7 @@ impl Submodule {
                collect_submodules(file_id, &file_items, module.item_list().unwrap())
            }
        };
-        return Ok(Arc::new(submodules));
+        return Arc::new(submodules);
        fn collect_submodules(
            file_id: HirFileId,
@@ -116,10 +116,10 @@ impl ModuleTree {
    pub(crate) fn module_tree_query(
        db: &impl HirDatabase,
        source_root: SourceRootId,
-    ) -> Cancelable<Arc<ModuleTree>> {
+    ) -> Arc<ModuleTree> {
-        db.check_canceled()?;
+        db.check_canceled();
        let res = create_module_tree(db, source_root);
-        Ok(Arc::new(res?))
+        Arc::new(res)
    }
    pub(crate) fn modules<'a>(&'a self) -> impl Iterator<Item = ModuleId> + 'a {
@@ -225,10 +225,7 @@ fn modules(root: &impl ast::ModuleItemOwner) -> impl Iterator<Item = (Name, &ast
        })
 }
-fn create_module_tree<'a>(
+fn create_module_tree<'a>(db: &impl HirDatabase, source_root: SourceRootId) -> ModuleTree {
-    db: &impl HirDatabase,
-    source_root: SourceRootId,
-) -> Cancelable<ModuleTree> {
    let mut tree = ModuleTree::default();
    let mut roots = FxHashMap::default();
@@ -252,10 +249,10 @@ fn create_module_tree<'a>(
            &mut roots,
            None,
            source,
-        )?;
+        );
        roots.insert(file_id, module_id);
    }
-    Ok(tree)
+    tree
 }
 fn build_subtree(
@@ -266,14 +263,14 @@ fn build_subtree(
    roots: &mut FxHashMap<FileId, ModuleId>,
    parent: Option<LinkId>,
    source: SourceItemId,
-) -> Cancelable<ModuleId> {
+) -> ModuleId {
    visited.insert(source);
    let id = tree.push_mod(ModuleData {
        source,
        parent,
        children: Vec::new(),
    });
-    for sub in db.submodules(source)?.iter() {
+    for sub in db.submodules(source).iter() {
        let link = tree.push_link(LinkData {
            source: sub.source,
            name: sub.name.clone(),
@@ -289,7 +286,7 @@ fn build_subtree(
                .map(|file_id| match roots.remove(&file_id) {
                    Some(module_id) => {
                        tree.mods[module_id].parent = Some(link);
-                        Ok(module_id)
+                        module_id
                    }
                    None => build_subtree(
                        db,
@@ -304,7 +301,7 @@ fn build_subtree(
                        },
                    ),
                })
-                .collect::<Cancelable<Vec<_>>>()?;
+                .collect::<Vec<_>>();
            (points_to, problem)
        } else {
            let points_to = build_subtree(
@@ -315,14 +312,14 @@ fn build_subtree(
                roots,
                Some(link),
                sub.source,
-            )?;
+            );
            (vec![points_to], None)
        };
        tree.links[link].points_to = points_to;
        tree.links[link].problem = problem;
    }
-    Ok(id)
+    id
 }
 fn resolve_submodule(
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index d9683549c..8d786d2ac 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -23,7 +23,7 @@ impl fmt::Debug for Name {
 }
 impl Name {
-    fn new(text: SmolStr) -> Name {
+    pub(crate) fn new(text: SmolStr) -> Name {
        Name { text }
    }
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index 6bf949654..484f668d0 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -22,7 +22,7 @@ use ra_syntax::{
    SyntaxKind::{self, *},
    ast::{self, AstNode}
 };
-use ra_db::{SourceRootId, Cancelable, FileId};
+use ra_db::{SourceRootId, FileId};
 use crate::{
    HirFileId,
@@ -319,30 +319,26 @@ where
        }
    }
-    pub(crate) fn resolve(mut self) -> Cancelable<ItemMap> {
+    pub(crate) fn resolve(mut self) -> ItemMap {
        for (&module_id, items) in self.input.iter() {
-            self.populate_module(module_id, Arc::clone(items))?;
+            self.populate_module(module_id, Arc::clone(items));
        }
        loop {
            let processed_imports_count = self.processed_imports.len();
            for &module_id in self.input.keys() {
-                self.db.check_canceled()?;
+                self.db.check_canceled();
-                self.resolve_imports(module_id)?;
+                self.resolve_imports(module_id);
            }
            if processed_imports_count == self.processed_imports.len() {
                // no new imports resolved
                break;
            }
        }
-        Ok(self.result)
+        self.result
    }
-    fn populate_module(
+    fn populate_module(&mut self, module_id: ModuleId, input: Arc<InputModuleItems>) {
-        &mut self,
-        module_id: ModuleId,
-        input: Arc<InputModuleItems>,
-    ) -> Cancelable<()> {
        let mut module_items = ModuleScope::default();
        // Populate extern crates prelude
@@ -353,8 +349,8 @@ where
            if let Some(crate_id) = crate_graph.crate_id_for_crate_root(file_id.as_original_file())
            {
                let krate = Crate::new(crate_id);
-                for dep in krate.dependencies(self.db)? {
+                for dep in krate.dependencies(self.db) {
-                    if let Some(module) = dep.krate.root_module(self.db)? {
+                    if let Some(module) = dep.krate.root_module(self.db) {
                        let def_id = module.def_id;
                        self.add_module_item(
                            &mut module_items,
@@ -415,7 +411,6 @@ where
        }
        self.result.per_module.insert(module_id, module_items);
-        Ok(())
    }
    fn add_module_item(&self, module_items: &mut ModuleScope, name: Name, def_id: PerNs<DefId>) {
@@ -426,24 +421,23 @@ where
        module_items.items.insert(name, resolution);
    }
-    fn resolve_imports(&mut self, module_id: ModuleId) -> Cancelable<()> {
+    fn resolve_imports(&mut self, module_id: ModuleId) {
        for (i, import) in self.input[&module_id].imports.iter().enumerate() {
            if self.processed_imports.contains(&(module_id, i)) {
                // already done
                continue;
            }
-            if self.resolve_import(module_id, import)? {
+            if self.resolve_import(module_id, import) {
                log::debug!("import {:?} resolved (or definite error)", import);
                self.processed_imports.insert((module_id, i));
            }
        }
-        Ok(())
    }
-    fn resolve_import(&mut self, module_id: ModuleId, import: &Import) -> Cancelable<bool> {
+    fn resolve_import(&mut self, module_id: ModuleId, import: &Import) -> bool {
        log::debug!("resolving import: {:?}", import);
        let ptr = match import.kind {
-            ImportKind::Glob => return Ok(false),
+            ImportKind::Glob => return false,
            ImportKind::Named(ptr) => ptr,
        };
@@ -455,7 +449,7 @@ where
                    None => {
                        // TODO: error
                        log::debug!("super path in root module");
-                        return Ok(true); // this can't suddenly resolve if we just resolve some other imports
+                        return true; // this can't suddenly resolve if we just resolve some other imports
                    }
                }
            }
@@ -469,7 +463,7 @@ where
                Some(res) if !res.def_id.is_none() => res.def_id,
                _ => {
                    log::debug!("path segment {:?} not found", name);
-                    return Ok(false);
+                    return false;
                }
            };
@@ -481,7 +475,7 @@ where
                        "path segment {:?} resolved to value only, but is not last",
                        name
                    );
-                    return Ok(false);
+                    return false;
                };
                curr = match type_def_id.loc(self.db) {
                    DefLoc {
@@ -499,7 +493,7 @@ where
                                kind: PathKind::Crate,
                            };
                            log::debug!("resolving {:?} in other source root", path);
-                            let def_id = module.resolve_path(self.db, &path)?;
+                            let def_id = module.resolve_path(self.db, &path);
                            if !def_id.is_none() {
                                let name = path.segments.last().unwrap();
                                self.update(module_id, |items| {
@@ -515,10 +509,10 @@ where
                                    import,
                                    def_id.map(|did| did.loc(self.db))
                                );
-                                return Ok(true);
+                                return true;
                            } else {
                                log::debug!("rest of path did not resolve in other source root");
-                                return Ok(true);
+                                return true;
                            }
                        }
                    }
@@ -528,7 +522,7 @@ where
                            name,
                            type_def_id.loc(self.db)
                        );
-                        return Ok(true); // this resolved to a non-module, so the path won't ever resolve
+                        return true; // this resolved to a non-module, so the path won't ever resolve
                    }
                }
            } else {
@@ -547,7 +541,7 @@ where
                })
            }
        }
-        Ok(true)
+        true
    }
    fn update(&mut self, module_id: ModuleId, f: impl FnOnce(&mut ModuleScope)) {
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index 647fd92aa..9a0474045 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -15,11 +15,9 @@ use crate::{
 fn item_map(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
    let (db, pos) = MockDatabase::with_position(fixture);
    let source_root = db.file_source_root(pos.file_id);
-    let module = crate::source_binder::module_from_position(&db, pos)
+    let module = crate::source_binder::module_from_position(&db, pos).unwrap();
-        .unwrap()
-        .unwrap();
    let module_id = module.def_id.loc(&db).module_id;
-    (db.item_map(source_root).unwrap(), module_id)
+    (db.item_map(source_root), module_id)
 }
 fn check_module_item_map(map: &ItemMap, module_id: ModuleId, expected: &str) {
@@ -242,11 +240,9 @@ fn item_map_across_crates() {
    db.set_crate_graph(crate_graph);
    let source_root = db.file_source_root(main_id);
-    let module = crate::source_binder::module_from_file_id(&db, main_id)
+    let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
-        .unwrap()
-        .unwrap();
    let module_id = module.def_id.loc(&db).module_id;
-    let item_map = db.item_map(source_root).unwrap();
+    let item_map = db.item_map(source_root);
    check_module_item_map(
        &item_map,
@@ -296,11 +292,9 @@ fn import_across_source_roots() {
    db.set_crate_graph(crate_graph);
-    let module = crate::source_binder::module_from_file_id(&db, main_id)
+    let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
-        .unwrap()
-        .unwrap();
    let module_id = module.def_id.loc(&db).module_id;
-    let item_map = db.item_map(source_root).unwrap();
+    let item_map = db.item_map(source_root);
    check_module_item_map(
        &item_map,
@@ -341,11 +335,9 @@ fn reexport_across_crates() {
    db.set_crate_graph(crate_graph);
    let source_root = db.file_source_root(main_id);
-    let module = crate::source_binder::module_from_file_id(&db, main_id)
+    let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
-        .unwrap()
-        .unwrap();
    let module_id = module.def_id.loc(&db).module_id;
-    let item_map = db.item_map(source_root).unwrap();
+    let item_map = db.item_map(source_root);
    check_module_item_map(
        &item_map,
@@ -362,7 +354,7 @@ fn check_item_map_is_not_recomputed(initial: &str, file_change: &str) {
    let source_root = db.file_source_root(pos.file_id);
    {
        let events = db.log_executed(|| {
-            db.item_map(source_root).unwrap();
+            db.item_map(source_root);
        });
        assert!(format!("{:?}", events).contains("item_map"))
    }
@@ -371,7 +363,7 @@ fn check_item_map_is_not_recomputed(initial: &str, file_change: &str) {
    {
        let events = db.log_executed(|| {
-            db.item_map(source_root).unwrap();
+            db.item_map(source_root);
        });
        assert!(
            !format!("{:?}", events).contains("item_map"),
diff --git a/crates/ra_hir/src/query_definitions.rs b/crates/ra_hir/src/query_definitions.rs
index 214a9d68b..24cb5c752 100644
--- a/crates/ra_hir/src/query_definitions.rs
+++ b/crates/ra_hir/src/query_definitions.rs
@@ -8,7 +8,7 @@ use ra_syntax::{
    AstNode, SyntaxNode, TreeArc,
    ast::{self, ModuleItemOwner}
 };
-use ra_db::{SourceRootId, Cancelable,};
+use ra_db::SourceRootId;
 use crate::{
    SourceFileItems, SourceItemId, DefId, HirFileId, ModuleSource,
@@ -18,10 +18,10 @@ use crate::{
    nameres::{InputModuleItems, ItemMap, Resolver},
 };
-pub(super) fn fn_scopes(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<FnScopes>> {
+pub(super) fn fn_scopes(db: &impl HirDatabase, def_id: DefId) -> Arc<FnScopes> {
-    let body = db.body_hir(def_id)?;
+    let body = db.body_hir(def_id);
    let res = FnScopes::new(body);
-    Ok(Arc::new(res))
+    Arc::new(res)
 }
 pub(super) fn file_items(db: &impl HirDatabase, file_id: HirFileId) -> Arc<SourceFileItems> {
@@ -47,8 +47,8 @@ pub(super) fn input_module_items(
    db: &impl HirDatabase,
    source_root_id: SourceRootId,
    module_id: ModuleId,
-) -> Cancelable<Arc<InputModuleItems>> {
+) -> Arc<InputModuleItems> {
-    let module_tree = db.module_tree(source_root_id)?;
+    let module_tree = db.module_tree(source_root_id);
    let source = module_id.source(&module_tree);
    let file_id = source.file_id;
    let source = ModuleSource::from_source_item_id(db, source);
@@ -90,26 +90,20 @@ pub(super) fn input_module_items(
            }
        }
    };
-    Ok(Arc::new(res))
+    Arc::new(res)
 }
-pub(super) fn item_map(
+pub(super) fn item_map(db: &impl HirDatabase, source_root: SourceRootId) -> Arc<ItemMap> {
-    db: &impl HirDatabase,
-    source_root: SourceRootId,
-) -> Cancelable<Arc<ItemMap>> {
    let start = Instant::now();
-    let module_tree = db.module_tree(source_root)?;
+    let module_tree = db.module_tree(source_root);
    let input = module_tree
        .modules()
-        .map(|id| {
+        .map(|id| (id, db.input_module_items(source_root, id)))
-            let items = db.input_module_items(source_root, id)?;
+        .collect::<FxHashMap<_, _>>();
-            Ok((id, items))
-        })
-        .collect::<Cancelable<FxHashMap<_, _>>>()?;
    let resolver = Resolver::new(db, &input, source_root, module_tree);
-    let res = resolver.resolve()?;
+    let res = resolver.resolve();
    let elapsed = start.elapsed();
    log::info!("item_map: {:?}", elapsed);
-    Ok(Arc::new(res))
+    Arc::new(res)
 }
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 1f149a366..7ab8eeae2 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -5,7 +5,7 @@
 ///
 /// So, this modules should not be used during hir construction, it exists
 /// purely for "IDE needs".
-use ra_db::{FileId, FilePosition, Cancelable};
+use ra_db::{FileId, FilePosition};
 use ra_syntax::{
    SmolStr, TextRange, SyntaxNode,
    ast::{self, AstNode, NameOwner},
@@ -18,7 +18,7 @@ use crate::{
 };
 /// Locates the module by `FileId`. Picks topmost module in the file.
-pub fn module_from_file_id(db: &impl HirDatabase, file_id: FileId) -> Cancelable<Option<Module>> {
+pub fn module_from_file_id(db: &impl HirDatabase, file_id: FileId) -> Option<Module> {
    let module_source = SourceItemId {
        file_id: file_id.into(),
        item_id: None,
@@ -31,25 +31,22 @@ pub fn module_from_declaration(
    db: &impl HirDatabase,
    file_id: FileId,
    decl: &ast::Module,
-) -> Cancelable<Option<Module>> {
+) -> Option<Module> {
-    let parent_module = module_from_file_id(db, file_id)?;
+    let parent_module = module_from_file_id(db, file_id);
    let child_name = decl.name();
    match (parent_module, child_name) {
        (Some(parent_module), Some(child_name)) => {
-            if let Some(child) = parent_module.child(db, &child_name.as_name())? {
+            if let Some(child) = parent_module.child(db, &child_name.as_name()) {
-                return Ok(Some(child));
+                return Some(child);
            }
        }
        _ => (),
    }
-    Ok(None)
+    None
 }
 /// Locates the module by position in the source code.
-pub fn module_from_position(
+pub fn module_from_position(db: &impl HirDatabase, position: FilePosition) -> Option<Module> {
-    db: &impl HirDatabase,
-    position: FilePosition,
-) -> Cancelable<Option<Module>> {
    let file = db.source_file(position.file_id);
    match find_node_at_offset::<ast::Module>(file.syntax(), position.offset) {
        Some(m) if !m.has_semi() => module_from_inline(db, position.file_id.into(), m),
@@ -61,7 +58,7 @@ fn module_from_inline(
    db: &impl HirDatabase,
    file_id: FileId,
    module: &ast::Module,
-) -> Cancelable<Option<Module>> {
+) -> Option<Module> {
    assert!(!module.has_semi());
    let file_id = file_id.into();
    let file_items = db.file_items(file_id);
@@ -78,7 +75,7 @@ pub fn module_from_child_node(
    db: &impl HirDatabase,
    file_id: FileId,
    child: &SyntaxNode,
-) -> Cancelable<Option<Module>> {
+) -> Option<Module> {
    if let Some(m) = child
        .ancestors()
        .filter_map(ast::Module::cast)
@@ -90,22 +87,16 @@ pub fn module_from_child_node(
    }
 }
-fn module_from_source(db: &impl HirDatabase, source: SourceItemId) -> Cancelable<Option<Module>> {
+fn module_from_source(db: &impl HirDatabase, source: SourceItemId) -> Option<Module> {
    let source_root_id = db.file_source_root(source.file_id.as_original_file());
-    let module_tree = db.module_tree(source_root_id)?;
+    let module_tree = db.module_tree(source_root_id);
-    let module_id = ctry!(module_tree.find_module_by_source(source));
+    let module_id = module_tree.find_module_by_source(source)?;
-    Ok(Some(Module::from_module_id(db, source_root_id, module_id)?))
+    Some(Module::from_module_id(db, source_root_id, module_id))
 }
-pub fn function_from_position(
+pub fn function_from_position(db: &impl HirDatabase, position: FilePosition) -> Option<Function> {
-    db: &impl HirDatabase,
-    position: FilePosition,
-) -> Cancelable<Option<Function>> {
    let file = db.source_file(position.file_id);
-    let fn_def = ctry!(find_node_at_offset::<ast::FnDef>(
+    let fn_def = find_node_at_offset::<ast::FnDef>(file.syntax(), position.offset)?;
-        file.syntax(),
-        position.offset
-    ));
    function_from_source(db, position.file_id, fn_def)
 }
@@ -113,10 +104,10 @@ pub fn function_from_source(
    db: &impl HirDatabase,
    file_id: FileId,
    fn_def: &ast::FnDef,
-) -> Cancelable<Option<Function>> {
+) -> Option<Function> {
-    let module = ctry!(module_from_child_node(db, file_id, fn_def.syntax())?);
+    let module = module_from_child_node(db, file_id, fn_def.syntax())?;
    let res = function_from_module(db, &module, fn_def);
-    Ok(Some(res))
+    Some(res)
 }
 pub fn function_from_module(
@@ -145,21 +136,18 @@ pub fn function_from_child_node(
    db: &impl HirDatabase,
    file_id: FileId,
    node: &SyntaxNode,
-) -> Cancelable<Option<Function>> {
+) -> Option<Function> {
-    let fn_def = ctry!(node.ancestors().find_map(ast::FnDef::cast));
+    let fn_def = node.ancestors().find_map(ast::FnDef::cast)?;
    function_from_source(db, file_id, fn_def)
 }
-pub fn macro_symbols(
+pub fn macro_symbols(db: &impl HirDatabase, file_id: FileId) -> Vec<(SmolStr, TextRange)> {
-    db: &impl HirDatabase,
+    let module = match module_from_file_id(db, file_id) {
-    file_id: FileId,
-) -> Cancelable<Vec<(SmolStr, TextRange)>> {
-    let module = match module_from_file_id(db, file_id)? {
        Some(it) => it,
-        None => return Ok(Vec::new()),
+        None => return Vec::new(),
    };
    let loc = module.def_id.loc(db);
-    let items = db.input_module_items(loc.source_root_id, loc.module_id)?;
+    let items = db.input_module_items(loc.source_root_id, loc.module_id);
    let mut res = Vec::new();
    for macro_call_id in items
@@ -184,5 +172,5 @@ pub fn macro_symbols(
        }
    }
-    Ok(res)
+    res
 }
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index fa46ddfe9..85d4dc05c 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -14,7 +14,7 @@
 //! rustc.
 mod autoderef;
-mod primitive;
+pub(crate) mod primitive;
 #[cfg(test)]
 mod tests;
 pub(crate) mod method_resolution;
@@ -30,25 +30,15 @@ use ra_arena::map::ArenaMap;
 use join_to_string::join;
 use rustc_hash::FxHashMap;
-use ra_db::Cancelable;
 use crate::{
    Def, DefId, Module, Function, Struct, Enum, EnumVariant, Path, Name, ImplBlock,
    FnSignature, FnScopes,
    db::HirDatabase,
    type_ref::{TypeRef, Mutability},
    name::KnownName,
-    expr::{Body, Expr, ExprId, PatId, UnaryOp, BinaryOp, Statement},
+    expr::{Body, Expr, Literal, ExprId, PatId, UnaryOp, BinaryOp, Statement},
 };
-fn transpose<T>(x: Cancelable<Option<T>>) -> Option<Cancelable<T>> {
-    match x {
-        Ok(Some(t)) => Some(Ok(t)),
-        Ok(None) => None,
-        Err(e) => Some(Err(e)),
-    }
-}
 /// The ID of a type variable.
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
 pub struct TypeVarId(u32);
@@ -107,13 +97,35 @@ impl UnifyValue for TypeVarValue {
    }
 }
-/// The kinds of placeholders we need during type inference. Currently, we only
+/// The kinds of placeholders we need during type inference. There's separate
-/// have type variables; in the future, we will probably also need int and float
+/// values for general types, and for integer and float variables. The latter
-/// variables, for inference of literal values (e.g. `100` could be one of
+/// two are used for inference of literal values (e.g. `100` could be one of
 /// several integer types).
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub enum InferTy {
    TypeVar(TypeVarId),
+    IntVar(TypeVarId),
+    FloatVar(TypeVarId),
+}
+impl InferTy {
+    fn to_inner(self) -> TypeVarId {
+        match self {
+            InferTy::TypeVar(ty) | InferTy::IntVar(ty) | InferTy::FloatVar(ty) => ty,
+        }
+    }
+    fn fallback_value(self) -> Ty {
+        match self {
+            InferTy::TypeVar(..) => Ty::Unknown,
+            InferTy::IntVar(..) => {
+                Ty::Int(primitive::UncertainIntTy::Signed(primitive::IntTy::I32))
+            }
+            InferTy::FloatVar(..) => {
+                Ty::Float(primitive::UncertainFloatTy::Known(primitive::FloatTy::F64))
+            }
+        }
+    }
 }
 /// When inferring an expression, we propagate downward whatever type hint we
@@ -151,14 +163,11 @@ pub enum Ty {
    /// (a non-surrogate code point). Written as `char`.
    Char,
-    /// A primitive signed integer type. For example, `i32`.
+    /// A primitive integer type. For example, `i32`.
-    Int(primitive::IntTy),
+    Int(primitive::UncertainIntTy),
-    /// A primitive unsigned integer type. For example, `u32`.
-    Uint(primitive::UintTy),
    /// A primitive floating-point type. For example, `f64`.
-    Float(primitive::FloatTy),
+    Float(primitive::UncertainFloatTy),
    /// Structures, enumerations and unions.
    Adt {
@@ -198,8 +207,9 @@ pub enum Ty {
    // above function pointer type. Once we implement generics, we will probably
    // need this as well.
-    // A trait, defined with `dyn trait`.
+    // A trait, defined with `dyn Trait`.
    // Dynamic(),
    // The anonymous type of a closure. Used to represent the type of
    // `|a| a`.
    // Closure(DefId, ClosureSubsts<'tcx>),
@@ -251,28 +261,28 @@ impl Ty {
        module: &Module,
        impl_block: Option<&ImplBlock>,
        type_ref: &TypeRef,
-    ) -> Cancelable<Self> {
+    ) -> Self {
-        Ok(match type_ref {
+        match type_ref {
            TypeRef::Never => Ty::Never,
            TypeRef::Tuple(inner) => {
                let inner_tys = inner
                    .iter()
                    .map(|tr| Ty::from_hir(db, module, impl_block, tr))
-                    .collect::<Cancelable<Vec<_>>>()?;
+                    .collect::<Vec<_>>();
                Ty::Tuple(inner_tys.into())
            }
-            TypeRef::Path(path) => Ty::from_hir_path(db, module, impl_block, path)?,
+            TypeRef::Path(path) => Ty::from_hir_path(db, module, impl_block, path),
            TypeRef::RawPtr(inner, mutability) => {
-                let inner_ty = Ty::from_hir(db, module, impl_block, inner)?;
+                let inner_ty = Ty::from_hir(db, module, impl_block, inner);
                Ty::RawPtr(Arc::new(inner_ty), *mutability)
            }
            TypeRef::Array(_inner) => Ty::Unknown, // TODO
            TypeRef::Slice(inner) => {
-                let inner_ty = Ty::from_hir(db, module, impl_block, inner)?;
+                let inner_ty = Ty::from_hir(db, module, impl_block, inner);
                Ty::Slice(Arc::new(inner_ty))
            }
            TypeRef::Reference(inner, mutability) => {
-                let inner_ty = Ty::from_hir(db, module, impl_block, inner)?;
+                let inner_ty = Ty::from_hir(db, module, impl_block, inner);
                Ty::Ref(Arc::new(inner_ty), *mutability)
            }
            TypeRef::Placeholder => Ty::Unknown,
@@ -280,7 +290,7 @@ impl Ty {
                let mut inner_tys = params
                    .iter()
                    .map(|tr| Ty::from_hir(db, module, impl_block, tr))
-                    .collect::<Cancelable<Vec<_>>>()?;
+                    .collect::<Vec<_>>();
                let return_ty = inner_tys
                    .pop()
                    .expect("TypeRef::Fn should always have at least return type");
@@ -291,7 +301,7 @@ impl Ty {
                Ty::FnPtr(Arc::new(sig))
            }
            TypeRef::Error => Ty::Unknown,
-        })
+        }
    }
    pub(crate) fn from_hir_opt(
@@ -299,10 +309,8 @@ impl Ty {
        module: &Module,
        impl_block: Option<&ImplBlock>,
        type_ref: Option<&TypeRef>,
-    ) -> Cancelable<Self> {
+    ) -> Self {
-        type_ref
+        type_ref.map_or(Ty::Unknown, |t| Ty::from_hir(db, module, impl_block, t))
-            .map(|t| Ty::from_hir(db, module, impl_block, t))
-            .unwrap_or(Ok(Ty::Unknown))
    }
    pub(crate) fn from_hir_path(
@@ -310,33 +318,31 @@ impl Ty {
        module: &Module,
        impl_block: Option<&ImplBlock>,
        path: &Path,
-    ) -> Cancelable<Self> {
+    ) -> Self {
        if let Some(name) = path.as_ident() {
-            if let Some(KnownName::Bool) = name.as_known_name() {
+            if let Some(int_ty) = primitive::UncertainIntTy::from_name(name) {
-                return Ok(Ty::Bool);
+                return Ty::Int(int_ty);
-            } else if let Some(KnownName::Char) = name.as_known_name() {
+            } else if let Some(float_ty) = primitive::UncertainFloatTy::from_name(name) {
-                return Ok(Ty::Char);
+                return Ty::Float(float_ty);
-            } else if let Some(KnownName::Str) = name.as_known_name() {
-                return Ok(Ty::Str);
-            } else if let Some(int_ty) = primitive::IntTy::from_name(name) {
-                return Ok(Ty::Int(int_ty));
-            } else if let Some(uint_ty) = primitive::UintTy::from_name(name) {
-                return Ok(Ty::Uint(uint_ty));
-            } else if let Some(float_ty) = primitive::FloatTy::from_name(name) {
-                return Ok(Ty::Float(float_ty));
            } else if name.as_known_name() == Some(KnownName::SelfType) {
                return Ty::from_hir_opt(db, module, None, impl_block.map(|i| i.target_type()));
+            } else if let Some(known) = name.as_known_name() {
+                match known {
+                    KnownName::Bool => return Ty::Bool,
+                    KnownName::Char => return Ty::Char,
+                    KnownName::Str => return Ty::Str,
+                    _ => {}
+                }
            }
        }
        // Resolve in module (in type namespace)
-        let resolved = if let Some(r) = module.resolve_path(db, path)?.take_types() {
+        let resolved = if let Some(r) = module.resolve_path(db, path).take_types() {
            r
        } else {
-            return Ok(Ty::Unknown);
+            return Ty::Unknown;
        };
-        let ty = db.type_for_def(resolved)?;
+        db.type_for_def(resolved)
-        Ok(ty)
    }
    pub fn unit() -> Self {
@@ -392,7 +398,6 @@ impl fmt::Display for Ty {
            Ty::Bool => write!(f, "bool"),
            Ty::Char => write!(f, "char"),
            Ty::Int(t) => write!(f, "{}", t.ty_to_string()),
-            Ty::Uint(t) => write!(f, "{}", t.ty_to_string()),
            Ty::Float(t) => write!(f, "{}", t.ty_to_string()),
            Ty::Str => write!(f, "str"),
            Ty::Slice(t) => write!(f, "[{}]", t),
@@ -427,47 +432,47 @@ impl fmt::Display for Ty {
 /// Compute the declared type of a function. This should not need to look at the
 /// function body.
-fn type_for_fn(db: &impl HirDatabase, f: Function) -> Cancelable<Ty> {
+fn type_for_fn(db: &impl HirDatabase, f: Function) -> Ty {
    let signature = f.signature(db);
-    let module = f.module(db)?;
+    let module = f.module(db);
-    let impl_block = f.impl_block(db)?;
+    let impl_block = f.impl_block(db);
    // TODO we ignore type parameters for now
    let input = signature
        .params()
        .iter()
        .map(|tr| Ty::from_hir(db, &module, impl_block.as_ref(), tr))
-        .collect::<Cancelable<Vec<_>>>()?;
+        .collect::<Vec<_>>();
-    let output = Ty::from_hir(db, &module, impl_block.as_ref(), signature.ret_type())?;
+    let output = Ty::from_hir(db, &module, impl_block.as_ref(), signature.ret_type());
    let sig = FnSig { input, output };
-    Ok(Ty::FnPtr(Arc::new(sig)))
+    Ty::FnPtr(Arc::new(sig))
 }
-fn type_for_struct(db: &impl HirDatabase, s: Struct) -> Cancelable<Ty> {
+fn type_for_struct(db: &impl HirDatabase, s: Struct) -> Ty {
-    Ok(Ty::Adt {
+    Ty::Adt {
        def_id: s.def_id(),
-        name: s.name(db)?.unwrap_or_else(Name::missing),
+        name: s.name(db).unwrap_or_else(Name::missing),
-    })
+    }
 }
-pub(crate) fn type_for_enum(db: &impl HirDatabase, s: Enum) -> Cancelable<Ty> {
+pub(crate) fn type_for_enum(db: &impl HirDatabase, s: Enum) -> Ty {
-    Ok(Ty::Adt {
+    Ty::Adt {
        def_id: s.def_id(),
-        name: s.name(db)?.unwrap_or_else(Name::missing),
+        name: s.name(db).unwrap_or_else(Name::missing),
-    })
+    }
 }
-pub(crate) fn type_for_enum_variant(db: &impl HirDatabase, ev: EnumVariant) -> Cancelable<Ty> {
+pub(crate) fn type_for_enum_variant(db: &impl HirDatabase, ev: EnumVariant) -> Ty {
-    let enum_parent = ev.parent_enum(db)?;
+    let enum_parent = ev.parent_enum(db);
    type_for_enum(db, enum_parent)
 }
-pub(super) fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Ty> {
+pub(super) fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Ty {
-    let def = def_id.resolve(db)?;
+    let def = def_id.resolve(db);
    match def {
        Def::Module(..) => {
            log::debug!("trying to get type for module {:?}", def_id);
-            Ok(Ty::Unknown)
+            Ty::Unknown
        }
        Def::Function(f) => type_for_fn(db, f),
        Def::Struct(s) => type_for_struct(db, s),
@@ -479,35 +484,26 @@ pub(super) fn type_for_def(db: &impl HirDatabase, def_id: DefId) -> Cancelable<T
                def_id,
                def
            );
-            Ok(Ty::Unknown)
+            Ty::Unknown
        }
    }
 }
-pub(super) fn type_for_field(
+pub(super) fn type_for_field(db: &impl HirDatabase, def_id: DefId, field: Name) -> Option<Ty> {
-    db: &impl HirDatabase,
+    let def = def_id.resolve(db);
-    def_id: DefId,
-    field: Name,
-) -> Cancelable<Option<Ty>> {
-    let def = def_id.resolve(db)?;
    let variant_data = match def {
-        Def::Struct(s) => s.variant_data(db)?,
+        Def::Struct(s) => s.variant_data(db),
-        Def::EnumVariant(ev) => ev.variant_data(db)?,
+        Def::EnumVariant(ev) => ev.variant_data(db),
        // TODO: unions
        _ => panic!(
            "trying to get type for field in non-struct/variant {:?}",
            def_id
        ),
    };
-    let module = def_id.module(db)?;
+    let module = def_id.module(db);
-    let impl_block = def_id.impl_block(db)?;
+    let impl_block = def_id.impl_block(db);
-    let type_ref = ctry!(variant_data.get_field_type_ref(&field));
+    let type_ref = variant_data.get_field_type_ref(&field)?;
-    Ok(Some(Ty::from_hir(
+    Some(Ty::from_hir(db, &module, impl_block.as_ref(), &type_ref))
-        db,
-        &module,
-        impl_block.as_ref(),
-        &type_ref,
-    )?))
 }