From d21cdf3c998bb24e48e81a7e6909df2146ce097c Mon Sep 17 00:00:00 2001
From: Florian Diebold <flodiebold@gmail.com>
Date: Sat, 7 Sep 2019 15:13:05 +0200
Subject: Lower `Fn(X, Y) -> Z` paths
---
crates/ra_hir/src/path.rs | 44 +++++++++++++++++++++++++++++++++++++++----
crates/ra_hir/src/ty/tests.rs | 16 ++++++++--------
2 files changed, 48 insertions(+), 12 deletions(-)
(limited to 'crates/ra_hir')
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index 24316fc91..d6c78593b 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -1,11 +1,11 @@
use std::sync::Arc;
use ra_syntax::{
- ast::{self, NameOwner},
+ ast::{self, NameOwner, TypeAscriptionOwner},
AstNode,
};
-use crate::{type_ref::TypeRef, AsName, Name};
+use crate::{name, type_ref::TypeRef, AsName, Name};
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Path {
@@ -76,8 +76,16 @@ impl Path {
match segment.kind()? {
ast::PathSegmentKind::Name(name) => {
- let args =
- segment.type_arg_list().and_then(GenericArgs::from_ast).map(Arc::new);
+ let args = segment
+ .type_arg_list()
+ .and_then(GenericArgs::from_ast)
+ .or_else(|| {
+ GenericArgs::from_fn_like_path_ast(
+ segment.param_list(),
+ segment.ret_type(),
+ )
+ })
+ .map(Arc::new);
let segment = PathSegment { name: name.as_name(), args_and_bindings: args };
segments.push(segment);
}
@@ -187,6 +195,34 @@ impl GenericArgs {
}
}
+ /// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)
+ /// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`).
+ pub(crate) fn from_fn_like_path_ast(
+ params: Option<ast::ParamList>,
+ ret_type: Option<ast::RetType>,
+ ) -> Option<GenericArgs> {
+ let mut args = Vec::new();
+ let mut bindings = Vec::new();
+ if let Some(params) = params {
+ let mut param_types = Vec::new();
+ for param in params.params() {
+ let type_ref = TypeRef::from_ast_opt(param.ascribed_type());
+ param_types.push(type_ref);
+ }
+ let arg = GenericArg::Type(TypeRef::Tuple(param_types));
+ args.push(arg);
+ }
+ if let Some(ret_type) = ret_type {
+ let type_ref = TypeRef::from_ast_opt(ret_type.type_ref());
+ bindings.push((name::OUTPUT, type_ref))
+ }
+ if args.is_empty() && bindings.is_empty() {
+ None
+ } else {
+ Some(GenericArgs { args, has_self_type: false, bindings })
+ }
+ }
+
pub(crate) fn empty() -> GenericArgs {
GenericArgs { args: Vec::new(), has_self_type: false, bindings: Vec::new() }
}
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index 17c4e3556..c414e6a95 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -3736,7 +3736,7 @@ fn fn_trait() {
trait FnOnce<Args> {
type Output;
- fn call_once(self, args: Args) -> Self::Output;
+ fn call_once(self, args: Args) -> <Self as FnOnce<Args>>::Output;
}
fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
@@ -3746,13 +3746,13 @@ fn test<F: FnOnce(u32, u64) -> u128>(f: F) {
@r###"
[57; 61) 'self': Self
[63; 67) 'args': Args
- [132; 133) 'f': F
- [138; 166) '{ ...2)); }': ()
- [144; 145) 'f': F
- [144; 163) 'f.call...1, 2))': {unknown}
- [156; 162) '(1, 2)': (i32, i32)
- [157; 158) '1': i32
- [160; 161) '2': i32
+ [150; 151) 'f': F
+ [156; 184) '{ ...2)); }': ()
+ [162; 163) 'f': F
+ [162; 181) 'f.call...1, 2))': {unknown}
+ [174; 180) '(1, 2)': (u32, u64)
+ [175; 176) '1': u32
+ [178; 179) '2': u64
"###
);
}
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