Add inlay hint for exclusive ranges

Adds an inlay hint containing a '<' character to exclusive range expressions and patterns that specify an upper bound.

crates/syntax/src/ast/expr_ext.rs

@@ -13,6 +13,8 @@ use crate::{
     SyntaxNode, SyntaxToken, T,
 };
 
+use super::RangeItem;
+
 impl ast::HasAttrs for ast::Expr {}
 
 impl ast::Expr {
@@ -227,16 +229,12 @@ impl ast::RangeExpr {
             Some((ix, token, bin_op))
         })
     }
+}
 
-    pub fn op_kind(&self) -> Option<RangeOp> {
-        self.op_details().map(|t| t.2)
-    }
+impl RangeItem for ast::RangeExpr {
+    type Bound = ast::Expr;
 
-    pub fn op_token(&self) -> Option<SyntaxToken> {
-        self.op_details().map(|t| t.1)
-    }
-
-    pub fn start(&self) -> Option<ast::Expr> {
+    fn start(&self) -> Option<ast::Expr> {
         let op_ix = self.op_details()?.0;
         self.syntax()
             .children_with_tokens()
@@ -244,13 +242,21 @@ impl ast::RangeExpr {
             .find_map(|it| ast::Expr::cast(it.into_node()?))
     }
 
-    pub fn end(&self) -> Option<ast::Expr> {
+    fn end(&self) -> Option<ast::Expr> {
         let op_ix = self.op_details()?.0;
         self.syntax()
             .children_with_tokens()
             .skip(op_ix + 1)
             .find_map(|it| ast::Expr::cast(it.into_node()?))
     }
+
+    fn op_token(&self) -> Option<SyntaxToken> {
+        self.op_details().map(|t| t.1)
+    }
+
+    fn op_kind(&self) -> Option<RangeOp> {
+        self.op_details().map(|t| t.2)
+    }
 }
 
 impl ast::IndexExpr {

crates/syntax/src/ast/node_ext.rs

@@ -14,6 +14,8 @@ use crate::{
     ted, NodeOrToken, SmolStr, SyntaxElement, SyntaxToken, TokenText, T,
 };
 
+use super::{RangeItem, RangeOp};
+
 impl ast::Lifetime {
     pub fn text(&self) -> TokenText<'_> {
         text_of_first_token(self.syntax())
@@ -875,8 +877,10 @@ impl ast::Module {
     }
 }
 
-impl ast::RangePat {
-    pub fn start(&self) -> Option<ast::Pat> {
+impl RangeItem for ast::RangePat {
+    type Bound = ast::Pat;
+
+    fn start(&self) -> Option<ast::Pat> {
         self.syntax()
             .children_with_tokens()
             .take_while(|it| !(it.kind() == T![..] || it.kind() == T![..=]))
@@ -884,13 +888,37 @@ impl ast::RangePat {
             .find_map(ast::Pat::cast)
     }
 
-    pub fn end(&self) -> Option<ast::Pat> {
+    fn end(&self) -> Option<ast::Pat> {
         self.syntax()
             .children_with_tokens()
             .skip_while(|it| !(it.kind() == T![..] || it.kind() == T![..=]))
             .filter_map(|it| it.into_node())
             .find_map(ast::Pat::cast)
     }
+
+    fn op_token(&self) -> Option<SyntaxToken> {
+        self.syntax().children_with_tokens().find_map(|it| {
+            let token = it.into_token()?;
+
+            match token.kind() {
+                T![..] => Some(token),
+                T![..=] => Some(token),
+                _ => None,
+            }
+        })
+    }
+
+    fn op_kind(&self) -> Option<RangeOp> {
+        self.syntax().children_with_tokens().find_map(|it| {
+            let token = it.into_token()?;
+
+            match token.kind() {
+                T![..] => Some(RangeOp::Exclusive),
+                T![..=] => Some(RangeOp::Inclusive),
+                _ => None,
+            }
+        })
+    }
 }
 
 impl ast::TokenTree {

crates/syntax/src/ast/prec.rs

@@ -1,7 +1,7 @@
 //! Precedence representation.
 
 use crate::{
-    ast::{self, BinaryOp, Expr, HasArgList},
+    ast::{self, BinaryOp, Expr, HasArgList, RangeItem},
     match_ast, AstNode, SyntaxNode,
 };