7 files changed, 72 insertions, 30 deletions

diff --git a/crates/ra_ide/src/completion/complete_fn_param.rs b/crates/ra_ide/src/completion/complete_fn_param.rs
index 62ae5ccb4..f84b559fc 100644
--- a/crates/ra_ide/src/completion/complete_fn_param.rs
+++ b/crates/ra_ide/src/completion/complete_fn_param.rs
@@ -1,6 +1,9 @@
 //! FIXME: write short doc here
 
-use ra_syntax::{ast, match_ast, AstNode};
+use ra_syntax::{
+    ast::{self, ModuleItemOwner},
+    match_ast, AstNode,
+};
 use rustc_hash::FxHashMap;
 
 use crate::completion::{CompletionContext, CompletionItem, CompletionKind, Completions};
@@ -16,11 +19,19 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
 
     let mut params = FxHashMap::default();
     for node in ctx.token.parent().ancestors() {
-        match_ast! {
+        let items = match_ast! {
             match node {
-                ast::SourceFile(it) => process(it, &mut params),
-                ast::ItemList(it) => process(it, &mut params),
-                _ => (),
+                ast::SourceFile(it) => it.items(),
+                ast::ItemList(it) => it.items(),
+                _ => continue,
+            }
+        };
+        for item in items {
+            if let ast::ModuleItem::FnDef(func) = item {
+                func.param_list().into_iter().flat_map(|it| it.params()).for_each(|param| {
+                    let text = param.syntax().text().to_string();
+                    params.entry(text).or_insert((0, param)).0 += 1;
+                })
             }
         }
     }
@@ -39,15 +50,6 @@ pub(super) fn complete_fn_param(acc: &mut Completions, ctx: &CompletionContext)
                 .lookup_by(lookup)
                 .add_to(acc)
         });
-
-    fn process<N: ast::FnDefOwner>(node: N, params: &mut FxHashMap<String, (u32, ast::Param)>) {
-        node.functions().filter_map(|it| it.param_list()).flat_map(|it| it.params()).for_each(
-            |param| {
-                let text = param.syntax().text().to_string();
-                params.entry(text).or_insert((0, param)).0 += 1;
-            },
-        )
-    }
 }
 
 #[cfg(test)]
diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index ded1ff3bc..fab02945c 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -35,7 +35,7 @@ use hir::{self, Docs, HasSource};
 use ra_assists::utils::get_missing_impl_items;
 use ra_syntax::{
     ast::{self, edit, ImplDef},
-    AstNode, SyntaxKind, SyntaxNode, TextRange,
+    AstNode, SyntaxKind, SyntaxNode, TextRange, T,
 };
 use ra_text_edit::TextEdit;
 
@@ -204,7 +204,7 @@ fn make_const_compl_syntax(const_: &ast::ConstDef) -> String {
     let end = const_
         .syntax()
         .children_with_tokens()
-        .find(|s| s.kind() == SyntaxKind::SEMI || s.kind() == SyntaxKind::EQ)
+        .find(|s| s.kind() == T![;] || s.kind() == T![=])
         .map_or(const_end, |f| f.text_range().start());
 
     let len = end - start;
diff --git a/crates/ra_ide/src/completion/completion_context.rs b/crates/ra_ide/src/completion/completion_context.rs
index 0e34d85db..6637afaf7 100644
--- a/crates/ra_ide/src/completion/completion_context.rs
+++ b/crates/ra_ide/src/completion/completion_context.rs
@@ -191,8 +191,8 @@ impl<'a> CompletionContext<'a> {
             if let Some(bind_pat) = name.syntax().ancestors().find_map(ast::BindPat::cast) {
                 self.is_pat_binding_or_const = true;
                 if bind_pat.at_token().is_some()
-                    || bind_pat.ref_kw_token().is_some()
-                    || bind_pat.mut_kw_token().is_some()
+                    || bind_pat.ref_token().is_some()
+                    || bind_pat.mut_token().is_some()
                 {
                     self.is_pat_binding_or_const = false;
                 }
diff --git a/crates/ra_ide/src/inlay_hints.rs b/crates/ra_ide/src/inlay_hints.rs
index 4b133b19b..da9f55a69 100644
--- a/crates/ra_ide/src/inlay_hints.rs
+++ b/crates/ra_ide/src/inlay_hints.rs
@@ -1,4 +1,4 @@
-//! FIXME: write short doc here
+//! This module defines multiple types of inlay hints and their visibility
 
 use hir::{Adt, HirDisplay, Semantics, Type};
 use ra_ide_db::RootDatabase;
@@ -235,8 +235,7 @@ fn should_show_param_hint(
     param_name: &str,
     argument: &ast::Expr,
 ) -> bool {
-    let argument_string = argument.syntax().to_string();
-    if param_name.is_empty() || argument_string.ends_with(param_name) {
+    if param_name.is_empty() || is_argument_similar_to_param(argument, param_name) {
         return false;
     }
 
@@ -245,14 +244,37 @@ fn should_show_param_hint(
     } else {
         fn_signature.parameters.len()
     };
+
     // avoid displaying hints for common functions like map, filter, etc.
-    if parameters_len == 1 && (param_name.len() == 1 || param_name == "predicate") {
+    // or other obvious words used in std
+    if parameters_len == 1 && is_obvious_param(param_name) {
         return false;
     }
-
     true
 }
 
+fn is_argument_similar_to_param(argument: &ast::Expr, param_name: &str) -> bool {
+    let argument_string = remove_ref(argument.clone()).syntax().to_string();
+    argument_string.starts_with(&param_name) || argument_string.ends_with(&param_name)
+}
+
+fn remove_ref(expr: ast::Expr) -> ast::Expr {
+    if let ast::Expr::RefExpr(ref_expr) = &expr {
+        if let Some(inner) = ref_expr.expr() {
+            return inner;
+        }
+    }
+    expr
+}
+
+fn is_obvious_param(param_name: &str) -> bool {
+    let is_obvious_param_name = match param_name {
+        "predicate" | "value" | "pat" | "rhs" | "other" => true,
+        _ => false,
+    };
+    param_name.len() == 1 || is_obvious_param_name
+}
+
 fn get_fn_signature(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<FunctionSignature> {
     match expr {
         ast::Expr::CallExpr(expr) => {
@@ -1059,9 +1081,18 @@ impl Test {
         self
     }
 
+    fn field(self, value: i32) -> Self {
+        self
+    }
+
     fn no_hints_expected(&self, _: i32, test_var: i32) {}
 }
 
+struct Param {}
+
+fn different_order(param: &Param) {}
+fn different_order_mut(param: &mut Param) {}
+
 fn main() {
     let container: TestVarContainer = TestVarContainer { test_var: 42 };
     let test: Test = Test {};
@@ -1069,11 +1100,20 @@ fn main() {
     map(22);
     filter(33);
 
-    let test_processed: Test = test.map(1).filter(2);
+    let test_processed: Test = test.map(1).filter(2).field(3);
 
     let test_var: i32 = 55;
     test_processed.no_hints_expected(22, test_var);
     test_processed.no_hints_expected(33, container.test_var);
+
+    let param_begin: Param = Param {};
+    different_order(&param_begin);
+    different_order(&mut param_begin);
+
+    let a: f64 = 7.0;
+    let b: f64 = 4.0;
+    let _: f64 = a.div_euclid(b);
+    let _: f64 = a.abs_sub(b);
 }"#,
         );
 
diff --git a/crates/ra_ide/src/references.rs b/crates/ra_ide/src/references.rs
index ad6fd50aa..7d0544ff4 100644
--- a/crates/ra_ide/src/references.rs
+++ b/crates/ra_ide/src/references.rs
@@ -152,7 +152,7 @@ fn decl_access(def: &Definition, syntax: &SyntaxNode, range: TextRange) -> Optio
     if stmt.initializer().is_some() {
         let pat = stmt.pat()?;
         if let ast::Pat::BindPat(it) = pat {
-            if it.mut_kw_token().is_some() {
+            if it.mut_token().is_some() {
                 return Some(ReferenceAccess::Write);
             }
         }
diff --git a/crates/ra_ide/src/syntax_tree.rs b/crates/ra_ide/src/syntax_tree.rs
index f58e436d1..5842ae2e8 100644
--- a/crates/ra_ide/src/syntax_tree.rs
+++ b/crates/ra_ide/src/syntax_tree.rs
@@ -165,7 +165,7 @@ SOURCE_FILE@[0; 60)
               PATH_SEGMENT@[16; 22)
                 NAME_REF@[16; 22)
                   IDENT@[16; 22) "assert"
-            EXCL@[22; 23) "!"
+            BANG@[22; 23) "!"
             TOKEN_TREE@[23; 57)
               L_PAREN@[23; 24) "("
               STRING@[24; 52) "\"\n    fn foo() {\n     ..."
@@ -173,7 +173,7 @@ SOURCE_FILE@[0; 60)
               WHITESPACE@[53; 54) " "
               STRING@[54; 56) "\"\""
               R_PAREN@[56; 57) ")"
-          SEMI@[57; 58) ";"
+          SEMICOLON@[57; 58) ";"
         WHITESPACE@[58; 59) "\n"
         R_CURLY@[59; 60) "}"
 "#
@@ -226,7 +226,7 @@ EXPR_STMT@[16; 58)
       PATH_SEGMENT@[16; 22)
         NAME_REF@[16; 22)
           IDENT@[16; 22) "assert"
-    EXCL@[22; 23) "!"
+    BANG@[22; 23) "!"
     TOKEN_TREE@[23; 57)
       L_PAREN@[23; 24) "("
       STRING@[24; 52) "\"\n    fn foo() {\n     ..."
@@ -234,7 +234,7 @@ EXPR_STMT@[16; 58)
       WHITESPACE@[53; 54) " "
       STRING@[54; 56) "\"\""
       R_PAREN@[56; 57) ")"
-  SEMI@[57; 58) ";"
+  SEMICOLON@[57; 58) ";"
 "#
             .trim()
         );
diff --git a/crates/ra_ide/src/typing.rs b/crates/ra_ide/src/typing.rs
index 71d2bcb04..f55cd3bf5 100644
--- a/crates/ra_ide/src/typing.rs
+++ b/crates/ra_ide/src/typing.rs
@@ -63,7 +63,7 @@ fn on_char_typed_inner(
 fn on_eq_typed(file: &SourceFile, offset: TextUnit) -> Option<SingleFileChange> {
     assert_eq!(file.syntax().text().char_at(offset), Some('='));
     let let_stmt: ast::LetStmt = find_node_at_offset(file.syntax(), offset)?;
-    if let_stmt.semi_token().is_some() {
+    if let_stmt.semicolon_token().is_some() {
         return None;
     }
     if let Some(expr) = let_stmt.initializer() {