closure parameter inlay hints

crates/ide/src/inlay_hints.rs

@@ -294,6 +294,7 @@ pub struct InlayHintsConfig {
     pub param_names_for_lifetime_elision_hints: bool,
     pub hide_named_constructor_hints: bool,
     pub hide_closure_initialization_hints: bool,
+    pub hide_closure_parameter_hints: bool,
     pub range_exclusive_hints: bool,
     pub closure_style: ClosureStyle,
     pub max_length: Option<usize>,
@@ -860,6 +861,7 @@ mod tests {
         binding_mode_hints: false,
         hide_named_constructor_hints: false,
         hide_closure_initialization_hints: false,
+        hide_closure_parameter_hints: false,
         closure_style: ClosureStyle::ImplFn,
         param_names_for_lifetime_elision_hints: false,
         max_length: None,

crates/ide/src/inlay_hints/bind_pat.rs

@@ -36,6 +36,11 @@ pub(super) fn hints(
                 if it.ty().is_some() {
                     return None;
                 }
+                if config.hide_closure_parameter_hints {
+                    if it.syntax().ancestors().any(|n| matches!(ast::Expr::cast(n), Some(ast::Expr::ClosureExpr(_)))) {
+                        return None;
+                    }
+                }
                 Some(it.colon_token())
             },
             ast::LetStmt(it) => {
@@ -949,6 +954,36 @@ fn bar(f: impl FnOnce(u8) -> u8) -> impl FnOnce(u8) -> u8 {
         );
     }
 
+    #[test]
+    fn skip_closure_parameter_hints() {
+        check_with_config(
+            InlayHintsConfig {
+                type_hints: true,
+                hide_closure_parameter_hints: true,
+                ..DISABLED_CONFIG
+            },
+            r#"
+//- minicore: fn
+struct Foo;
+impl Foo {
+    fn foo(self: Self) {}
+    fn bar(self: &Self) {}
+}
+fn main() {
+    let closure = |x, y| x + y;
+    //  ^^^^^^^ impl Fn(i32, i32) -> {unknown}
+    closure(2, 3);
+    let point = (10, 20);
+    //  ^^^^^ (i32, i32)
+    let (x,      y) = point;
+      // ^ i32   ^ i32
+    Foo::foo(Foo);
+    Foo::bar(&Foo);
+}
+"#,
+        );
+    }
+
     #[test]
     fn hint_truncation() {
         check_with_config(

crates/ide/src/inlay_hints/closure_captures.rs

@@ -1,4 +1,4 @@
-//! Implementation of "closure return type" inlay hints.
+//! Implementation of "closure captures" inlay hints.
 //!
 //! Tests live in [`bind_pat`][super::bind_pat] module.
 use ide_db::famous_defs::FamousDefs;

crates/ide/src/static_index.rs

@@ -154,6 +154,7 @@ impl StaticIndex<'_> {
                     implicit_drop_hints: false,
                     hide_named_constructor_hints: false,
                     hide_closure_initialization_hints: false,
+                    hide_closure_parameter_hints: false,
                     closure_style: hir::ClosureStyle::ImplFn,
                     param_names_for_lifetime_elision_hints: false,
                     binding_mode_hints: false,

crates/rust-analyzer/src/cli/analysis_stats.rs

@@ -1072,6 +1072,7 @@ impl flags::AnalysisStats {
                     param_names_for_lifetime_elision_hints: true,
                     hide_named_constructor_hints: false,
                     hide_closure_initialization_hints: false,
+                    hide_closure_parameter_hints: false,
                     closure_style: hir::ClosureStyle::ImplFn,
                     max_length: Some(25),
                     closing_brace_hints_min_lines: Some(20),

crates/rust-analyzer/src/config.rs

@@ -208,6 +208,8 @@ config_data! {
         /// Whether to hide inlay type hints for `let` statements that initialize to a closure.
         /// Only applies to closures with blocks, same as `#rust-analyzer.inlayHints.closureReturnTypeHints.enable#`.
         inlayHints_typeHints_hideClosureInitialization: bool       = false,
+        /// Whether to hide inlay parameter type hints for closures.
+        inlayHints_typeHints_hideClosureParameter:bool             = false,
         /// Whether to hide inlay type hints for constructors.
         inlayHints_typeHints_hideNamedConstructor: bool            = false,
 
@@ -1666,6 +1668,9 @@ impl Config {
             hide_closure_initialization_hints: self
                 .inlayHints_typeHints_hideClosureInitialization()
                 .to_owned(),
+            hide_closure_parameter_hints: self
+                .inlayHints_typeHints_hideClosureParameter()
+                .to_owned(),
             closure_style: match self.inlayHints_closureStyle() {
                 ClosureStyle::ImplFn => hir::ClosureStyle::ImplFn,
                 ClosureStyle::RustAnalyzer => hir::ClosureStyle::RANotation,

docs/book/src/configuration_generated.md

@@ -782,6 +782,11 @@ This setting is deprecated in favor of #rust-analyzer.inlayHints.expressionAdjus
 Only applies to closures with blocks, same as `#rust-analyzer.inlayHints.closureReturnTypeHints.enable#`.
 
 
+**rust-analyzer.inlayHints.typeHints.hideClosureParameter** (default: false)
+
+ Whether to hide inlay parameter type hints for closures.
+
+
 **rust-analyzer.inlayHints.typeHints.hideNamedConstructor** (default: false)
 
  Whether to hide inlay type hints for constructors.

editors/code/package.json

@@ -2253,6 +2253,16 @@
                     }
                 }
             },
+            {
+                "title": "inlayHints",
+                "properties": {
+                    "rust-analyzer.inlayHints.typeHints.hideClosureParameter": {
+                        "markdownDescription": "Whether to hide inlay parameter type hints for closures.",
+                        "default": false,
+                        "type": "boolean"
+                    }
+                }
+            },
             {
                 "title": "inlayHints",
                 "properties": {