8 files changed, 113 insertions, 127 deletions

diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index 1f3981f5a..2e521183c 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -17,7 +17,7 @@ rowan = "0.5.0"
 
 # ideally, `serde` should be enabled by `ra_lsp_server`, but we enable it here
 # to reduce number of compilations
-text_unit = { version = "0.1.6", features = ["serde"] }
+text_unit = { version = "0.1.8", features = ["serde"] }
 smol_str = { version = "0.1.9", features = ["serde"] }
 
 ra_text_edit = { path = "../ra_text_edit" }
diff --git a/crates/ra_syntax/src/ast/expr_extensions.rs b/crates/ra_syntax/src/ast/expr_extensions.rs
index 9484c3b9b..17763809d 100644
--- a/crates/ra_syntax/src/ast/expr_extensions.rs
+++ b/crates/ra_syntax/src/ast/expr_extensions.rs
@@ -3,7 +3,8 @@
 use crate::{
     SyntaxToken, SyntaxElement, SmolStr,
     ast::{self, AstNode, AstChildren, children, child_opt},
-    SyntaxKind::*
+    SyntaxKind::*,
+    T
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -34,7 +35,7 @@ impl ast::IfExpr {
 
 impl ast::RefExpr {
     pub fn is_mut(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
     }
 }
 
@@ -51,9 +52,9 @@ pub enum PrefixOp {
 impl ast::PrefixExpr {
     pub fn op_kind(&self) -> Option<PrefixOp> {
         match self.op_token()?.kind() {
-            STAR => Some(PrefixOp::Deref),
-            EXCL => Some(PrefixOp::Not),
-            MINUS => Some(PrefixOp::Neg),
+            T![*] => Some(PrefixOp::Deref),
+            T![!] => Some(PrefixOp::Not),
+            T![-] => Some(PrefixOp::Neg),
             _ => None,
         }
     }
@@ -133,37 +134,37 @@ impl ast::BinExpr {
     fn op_details(&self) -> Option<(SyntaxToken, BinOp)> {
         self.syntax().children_with_tokens().filter_map(|it| it.as_token()).find_map(|c| {
             match c.kind() {
-                PIPEPIPE => Some((c, BinOp::BooleanOr)),
-                AMPAMP => Some((c, BinOp::BooleanAnd)),
-                EQEQ => Some((c, BinOp::EqualityTest)),
-                NEQ => Some((c, BinOp::NegatedEqualityTest)),
-                LTEQ => Some((c, BinOp::LesserEqualTest)),
-                GTEQ => Some((c, BinOp::GreaterEqualTest)),
-                L_ANGLE => Some((c, BinOp::LesserTest)),
-                R_ANGLE => Some((c, BinOp::GreaterTest)),
-                PLUS => Some((c, BinOp::Addition)),
-                STAR => Some((c, BinOp::Multiplication)),
-                MINUS => Some((c, BinOp::Subtraction)),
-                SLASH => Some((c, BinOp::Division)),
-                PERCENT => Some((c, BinOp::Remainder)),
-                SHL => Some((c, BinOp::LeftShift)),
-                SHR => Some((c, BinOp::RightShift)),
-                CARET => Some((c, BinOp::BitwiseXor)),
-                PIPE => Some((c, BinOp::BitwiseOr)),
-                AMP => Some((c, BinOp::BitwiseAnd)),
-                DOTDOT => Some((c, BinOp::RangeRightOpen)),
-                DOTDOTEQ => Some((c, BinOp::RangeRightClosed)),
-                EQ => Some((c, BinOp::Assignment)),
-                PLUSEQ => Some((c, BinOp::AddAssign)),
-                SLASHEQ => Some((c, BinOp::DivAssign)),
-                STAREQ => Some((c, BinOp::MulAssign)),
-                PERCENTEQ => Some((c, BinOp::RemAssign)),
-                SHREQ => Some((c, BinOp::ShrAssign)),
-                SHLEQ => Some((c, BinOp::ShlAssign)),
-                MINUSEQ => Some((c, BinOp::SubAssign)),
-                PIPEEQ => Some((c, BinOp::BitOrAssign)),
-                AMPEQ => Some((c, BinOp::BitAndAssign)),
-                CARETEQ => Some((c, BinOp::BitXorAssign)),
+                T![||] => Some((c, BinOp::BooleanOr)),
+                T![&&] => Some((c, BinOp::BooleanAnd)),
+                T![==] => Some((c, BinOp::EqualityTest)),
+                T![!=] => Some((c, BinOp::NegatedEqualityTest)),
+                T![<=] => Some((c, BinOp::LesserEqualTest)),
+                T![>=] => Some((c, BinOp::GreaterEqualTest)),
+                T![<] => Some((c, BinOp::LesserTest)),
+                T![>] => Some((c, BinOp::GreaterTest)),
+                T![+] => Some((c, BinOp::Addition)),
+                T![*] => Some((c, BinOp::Multiplication)),
+                T![-] => Some((c, BinOp::Subtraction)),
+                T![/] => Some((c, BinOp::Division)),
+                T![%] => Some((c, BinOp::Remainder)),
+                T![<<] => Some((c, BinOp::LeftShift)),
+                T![>>] => Some((c, BinOp::RightShift)),
+                T![^] => Some((c, BinOp::BitwiseXor)),
+                T![|] => Some((c, BinOp::BitwiseOr)),
+                T![&] => Some((c, BinOp::BitwiseAnd)),
+                T![..] => Some((c, BinOp::RangeRightOpen)),
+                T![..=] => Some((c, BinOp::RangeRightClosed)),
+                T![=] => Some((c, BinOp::Assignment)),
+                T![+=] => Some((c, BinOp::AddAssign)),
+                T![/=] => Some((c, BinOp::DivAssign)),
+                T![*=] => Some((c, BinOp::MulAssign)),
+                T![%=] => Some((c, BinOp::RemAssign)),
+                T![>>=] => Some((c, BinOp::ShrAssign)),
+                T![<<=] => Some((c, BinOp::ShlAssign)),
+                T![-=] => Some((c, BinOp::SubAssign)),
+                T![|=] => Some((c, BinOp::BitOrAssign)),
+                T![&=] => Some((c, BinOp::BitAndAssign)),
+                T![^=] => Some((c, BinOp::BitXorAssign)),
                 _ => None,
             }
         })
@@ -211,7 +212,7 @@ impl ast::ArrayExpr {
     }
 
     fn is_repeat(&self) -> bool {
-        self.syntax().children_with_tokens().any(|it| it.kind() == SEMI)
+        self.syntax().children_with_tokens().any(|it| it.kind() == T![;])
     }
 }
 
@@ -258,7 +259,7 @@ impl ast::Literal {
                 LiteralKind::FloatNumber { suffix: suffix }
             }
             STRING | RAW_STRING => LiteralKind::String,
-            TRUE_KW | FALSE_KW => LiteralKind::Bool,
+            T![true] | T![false] => LiteralKind::Bool,
             BYTE_STRING | RAW_BYTE_STRING => LiteralKind::ByteString,
             CHAR => LiteralKind::Char,
             BYTE => LiteralKind::Byte,
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index f3466c585..f030e0df8 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -3,7 +3,7 @@
 
 use itertools::Itertools;
 
-use crate::{SmolStr, SyntaxToken, ast::{self, AstNode, children, child_opt}, SyntaxKind::*, SyntaxElement};
+use crate::{SmolStr, SyntaxToken, ast::{self, AstNode, children, child_opt}, SyntaxKind::*, SyntaxElement, T};
 use ra_parser::SyntaxKind;
 
 impl ast::Name {
@@ -32,7 +32,7 @@ impl ast::Attr {
             Some(prev) => prev,
         };
 
-        prev.kind() == EXCL
+        prev.kind() == T![!]
     }
 
     pub fn as_atom(&self) -> Option<SmolStr> {
@@ -102,9 +102,9 @@ impl ast::PathSegment {
             PathSegmentKind::Name(name_ref)
         } else {
             match self.syntax().first_child_or_token()?.kind() {
-                SELF_KW => PathSegmentKind::SelfKw,
-                SUPER_KW => PathSegmentKind::SuperKw,
-                CRATE_KW => PathSegmentKind::CrateKw,
+                T![self] => PathSegmentKind::SelfKw,
+                T![super] => PathSegmentKind::SuperKw,
+                T![crate] => PathSegmentKind::CrateKw,
                 _ => return None,
             }
         };
@@ -113,7 +113,7 @@ impl ast::PathSegment {
 
     pub fn has_colon_colon(&self) -> bool {
         match self.syntax.first_child_or_token().map(|s| s.kind()) {
-            Some(COLONCOLON) => true,
+            Some(T![::]) => true,
             _ => false,
         }
     }
@@ -129,14 +129,14 @@ impl ast::Module {
     pub fn has_semi(&self) -> bool {
         match self.syntax().last_child_or_token() {
             None => false,
-            Some(node) => node.kind() == SEMI,
+            Some(node) => node.kind() == T![;],
         }
     }
 }
 
 impl ast::UseTree {
     pub fn has_star(&self) -> bool {
-        self.syntax().children_with_tokens().any(|it| it.kind() == STAR)
+        self.syntax().children_with_tokens().any(|it| it.kind() == T![*])
     }
 }
 
@@ -172,7 +172,7 @@ impl ast::ImplBlock {
     }
 
     pub fn is_negative(&self) -> bool {
-        self.syntax().children_with_tokens().any(|t| t.kind() == EXCL)
+        self.syntax().children_with_tokens().any(|t| t.kind() == T![!])
     }
 }
 
@@ -219,7 +219,7 @@ impl ast::FnDef {
         self.syntax()
             .last_child_or_token()
             .and_then(|it| it.as_token())
-            .filter(|it| it.kind() == SEMI)
+            .filter(|it| it.kind() == T![;])
     }
 }
 
@@ -227,7 +227,7 @@ impl ast::LetStmt {
     pub fn has_semi(&self) -> bool {
         match self.syntax().last_child_or_token() {
             None => false,
-            Some(node) => node.kind() == SEMI,
+            Some(node) => node.kind() == T![;],
         }
     }
 }
@@ -236,7 +236,7 @@ impl ast::ExprStmt {
     pub fn has_semi(&self) -> bool {
         match self.syntax().last_child_or_token() {
             None => false,
-            Some(node) => node.kind() == SEMI,
+            Some(node) => node.kind() == T![;],
         }
     }
 }
@@ -270,29 +270,29 @@ impl ast::FieldExpr {
 
 impl ast::RefPat {
     pub fn is_mut(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
     }
 }
 
 impl ast::BindPat {
     pub fn is_mutable(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
     }
 
     pub fn is_ref(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == REF_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![ref])
     }
 }
 
 impl ast::PointerType {
     pub fn is_mut(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
     }
 }
 
 impl ast::ReferenceType {
     pub fn is_mut(&self) -> bool {
-        self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
+        self.syntax().children_with_tokens().any(|n| n.kind() == T![mut])
     }
 }
 
@@ -311,19 +311,19 @@ impl ast::SelfParam {
         self.syntax()
             .children_with_tokens()
             .filter_map(|it| it.as_token())
-            .find(|it| it.kind() == SELF_KW)
+            .find(|it| it.kind() == T![self])
             .expect("invalid tree: self param must have self")
     }
 
     pub fn kind(&self) -> SelfParamKind {
-        let borrowed = self.syntax().children_with_tokens().any(|n| n.kind() == AMP);
+        let borrowed = self.syntax().children_with_tokens().any(|n| n.kind() == T![&]);
         if borrowed {
             // check for a `mut` coming after the & -- `mut &self` != `&mut self`
             if self
                 .syntax()
                 .children_with_tokens()
-                .skip_while(|n| n.kind() != AMP)
-                .any(|n| n.kind() == MUT_KW)
+                .skip_while(|n| n.kind() != T![&])
+                .any(|n| n.kind() == T![mut])
             {
                 SelfParamKind::MutRef
             } else {
@@ -355,6 +355,6 @@ impl ast::WherePred {
 
 impl ast::TraitDef {
     pub fn is_auto(&self) -> bool {
-        self.syntax().children_with_tokens().any(|t| t.kind() == AUTO_KW)
+        self.syntax().children_with_tokens().any(|t| t.kind() == T![auto])
     }
 }
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index 65c65d6aa..0ceabc203 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -179,10 +179,7 @@ fn api_walkthrough() {
 
     // There's a bunch of traversal methods on `SyntaxNode`:
     assert_eq!(expr_syntax.parent(), Some(block.syntax()));
-    assert_eq!(
-        block.syntax().first_child_or_token().map(|it| it.kind()),
-        Some(SyntaxKind::L_CURLY)
-    );
+    assert_eq!(block.syntax().first_child_or_token().map(|it| it.kind()), Some(T!['{']));
     assert_eq!(
         expr_syntax.next_sibling_or_token().map(|it| it.kind()),
         Some(SyntaxKind::WHITESPACE)
@@ -191,9 +188,7 @@ fn api_walkthrough() {
     // As well as some iterator helpers:
     let f = expr_syntax.ancestors().find_map(ast::FnDef::cast);
     assert_eq!(f, Some(&*func));
-    assert!(expr_syntax
-        .siblings_with_tokens(Direction::Next)
-        .any(|it| it.kind() == SyntaxKind::R_CURLY));
+    assert!(expr_syntax.siblings_with_tokens(Direction::Next).any(|it| it.kind() == T!['}']));
     assert_eq!(
         expr_syntax.descendants_with_tokens().count(),
         8, // 5 tokens `1`, ` `, `+`, ` `, `!`
diff --git a/crates/ra_syntax/src/parsing/lexer.rs b/crates/ra_syntax/src/parsing/lexer.rs
index a3791b503..6eb96f03d 100644
--- a/crates/ra_syntax/src/parsing/lexer.rs
+++ b/crates/ra_syntax/src/parsing/lexer.rs
@@ -7,6 +7,7 @@ mod strings;
 use crate::{
     SyntaxKind::{self, *},
     TextUnit,
+    T,
 };
 
 use self::{
@@ -90,16 +91,16 @@ fn next_token_inner(c: char, ptr: &mut Ptr) -> SyntaxKind {
     match c {
         // Possiblily multi-byte tokens,
         // but we only produce single byte token now
-        // DOTDOTDOT, DOTDOT, DOTDOTEQ, DOT
-        '.' => return DOT,
-        // COLONCOLON COLON
-        ':' => return COLON,
-        // EQEQ FATARROW EQ
-        '=' => return EQ,
-        // NEQ EXCL
-        '!' => return EXCL,
-        // THIN_ARROW MINUS
-        '-' => return MINUS,
+        // T![...], T![..], T![..=], T![.]
+        '.' => return T![.],
+        // T![::] T![:]
+        ':' => return T![:],
+        // T![==] FATARROW T![=]
+        '=' => return T![=],
+        // T![!=] T![!]
+        '!' => return T![!],
+        // T![->] T![-]
+        '-' => return T![-],
 
         // If the character is an ident start not followed by another single
         // quote, then this is a lifetime name:
@@ -148,8 +149,8 @@ fn scan_ident(c: char, ptr: &mut Ptr) -> SyntaxKind {
             ptr.bump();
             true
         }
-        ('_', None) => return UNDERSCORE,
-        ('_', Some(c)) if !is_ident_continue(c) => return UNDERSCORE,
+        ('_', None) => return T![_],
+        ('_', Some(c)) if !is_ident_continue(c) => return T![_],
         _ => false,
     };
     ptr.bump_while(is_ident_continue);
diff --git a/crates/ra_syntax/src/parsing/reparsing.rs b/crates/ra_syntax/src/parsing/reparsing.rs
index 434f850d1..6de02a15a 100644
--- a/crates/ra_syntax/src/parsing/reparsing.rs
+++ b/crates/ra_syntax/src/parsing/reparsing.rs
@@ -17,7 +17,8 @@ use crate::{
         text_token_source::TextTokenSource,
         text_tree_sink::TextTreeSink,
         lexer::{tokenize, Token},
-    }
+    },
+    T,
 };
 
 pub(crate) fn incremental_reparse(
@@ -122,16 +123,16 @@ fn find_reparsable_node(node: &SyntaxNode, range: TextRange) -> Option<(&SyntaxN
 
 fn is_balanced(tokens: &[Token]) -> bool {
     if tokens.is_empty()
-        || tokens.first().unwrap().kind != L_CURLY
-        || tokens.last().unwrap().kind != R_CURLY
+        || tokens.first().unwrap().kind != T!['{']
+        || tokens.last().unwrap().kind != T!['}']
     {
         return false;
     }
     let mut balance = 0usize;
     for t in &tokens[1..tokens.len() - 1] {
         match t.kind {
-            L_CURLY => balance += 1,
-            R_CURLY => {
+            T!['{'] => balance += 1,
+            T!['}'] => {
                 balance = match balance.checked_sub(1) {
                     Some(b) => b,
                     None => return false,
diff --git a/crates/ra_syntax/src/syntax_text.rs b/crates/ra_syntax/src/syntax_text.rs
index 6bb2ff461..b013164c4 100644
--- a/crates/ra_syntax/src/syntax_text.rs
+++ b/crates/ra_syntax/src/syntax_text.rs
@@ -1,4 +1,4 @@
-use std::{fmt, ops};
+use std::{fmt, ops::{self, Bound}};
 
 use crate::{SyntaxNode, TextRange, TextUnit, SyntaxElement};
 
@@ -54,10 +54,31 @@ impl<'a> SyntaxText<'a> {
         self.range.len()
     }
 
-    pub fn slice(&self, range: impl SyntaxTextSlice) -> SyntaxText<'a> {
-        let range = range.restrict(self.range).unwrap_or_else(|| {
-            panic!("invalid slice, range: {:?}, slice: {:?}", self.range, range)
-        });
+    /// NB, the offsets here are absolute, and this probably doesn't make sense!
+    pub fn slice(&self, range: impl ops::RangeBounds<TextUnit>) -> SyntaxText<'a> {
+        let start = match range.start_bound() {
+            Bound::Included(b) => *b,
+            Bound::Excluded(b) => *b + TextUnit::from(1u32),
+            Bound::Unbounded => self.range.start(),
+        };
+        let end = match range.end_bound() {
+            Bound::Included(b) => *b + TextUnit::from(1u32),
+            Bound::Excluded(b) => *b,
+            Bound::Unbounded => self.range.end(),
+        };
+        assert!(
+            start <= end,
+            "invalid slice, range: {:?}, slice: {:?}",
+            self.range,
+            (range.start_bound(), range.end_bound()),
+        );
+        let range = TextRange::from_to(start, end);
+        assert!(
+            range.is_subrange(&self.range),
+            "invalid slice, range: {:?}, slice: {:?}",
+            self.range,
+            range,
+        );
         SyntaxText { node: self.node, range }
     }
 
@@ -88,40 +109,6 @@ impl<'a> fmt::Display for SyntaxText<'a> {
     }
 }
 
-pub trait SyntaxTextSlice: fmt::Debug {
-    fn restrict(&self, range: TextRange) -> Option<TextRange>;
-}
-
-impl SyntaxTextSlice for TextRange {
-    fn restrict(&self, range: TextRange) -> Option<TextRange> {
-        self.intersection(&range)
-    }
-}
-
-impl SyntaxTextSlice for ops::RangeTo<TextUnit> {
-    fn restrict(&self, range: TextRange) -> Option<TextRange> {
-        if !range.contains_inclusive(self.end) {
-            return None;
-        }
-        Some(TextRange::from_to(range.start(), self.end))
-    }
-}
-
-impl SyntaxTextSlice for ops::RangeFrom<TextUnit> {
-    fn restrict(&self, range: TextRange) -> Option<TextRange> {
-        if !range.contains_inclusive(self.start) {
-            return None;
-        }
-        Some(TextRange::from_to(self.start, range.end()))
-    }
-}
-
-impl SyntaxTextSlice for ops::Range<TextUnit> {
-    fn restrict(&self, range: TextRange) -> Option<TextRange> {
-        TextRange::from_to(self.start, self.end).restrict(range)
-    }
-}
-
 impl From<SyntaxText<'_>> for String {
     fn from(text: SyntaxText) -> String {
         text.to_string()
diff --git a/crates/ra_syntax/src/validation.rs b/crates/ra_syntax/src/validation.rs
index 11a1fb4a7..b53900a4b 100644
--- a/crates/ra_syntax/src/validation.rs
+++ b/crates/ra_syntax/src/validation.rs
@@ -5,9 +5,10 @@ mod field_expr;
 
 use crate::{
     SourceFile, SyntaxError, AstNode, SyntaxNode, TextUnit,
-    SyntaxKind::{L_CURLY, R_CURLY, BYTE, BYTE_STRING, STRING, CHAR},
+    SyntaxKind::{BYTE, BYTE_STRING, STRING, CHAR},
     ast,
     algo::visit::{visitor_ctx, VisitorCtx},
+    T,
 };
 
 pub(crate) use unescape::EscapeError;
@@ -83,8 +84,8 @@ pub(crate) fn validate_block_structure(root: &SyntaxNode) {
     let mut stack = Vec::new();
     for node in root.descendants() {
         match node.kind() {
-            L_CURLY => stack.push(node),
-            R_CURLY => {
+            T!['{'] => stack.push(node),
+            T!['}'] => {
                 if let Some(pair) = stack.pop() {
                     assert_eq!(
                         node.parent(),