1 files changed, 82 insertions, 70 deletions

diff --git a/crates/ide_completion/src/context.rs b/crates/ide_completion/src/context.rs
index cb4f08e53..6177caa12 100644
--- a/crates/ide_completion/src/context.rs
+++ b/crates/ide_completion/src/context.rs
@@ -29,6 +29,29 @@ pub(crate) enum PatternRefutability {
     Irrefutable,
 }
 
+#[derive(Debug)]
+pub(crate) struct PathCompletionContext {
+    /// If this is a call with () already there
+    call_kind: Option<CallKind>,
+    /// A single-indent path, like `foo`. `::foo` should not be considered a trivial path.
+    pub(super) is_trivial_path: bool,
+    /// If not a trivial path, the prefix (qualifier).
+    pub(super) path_qual: Option<ast::Path>,
+    pub(super) is_path_type: bool,
+    pub(super) has_type_args: bool,
+    /// `true` if we are a statement or a last expr in the block.
+    pub(super) can_be_stmt: bool,
+    /// `true` if we expect an expression at the cursor position.
+    pub(super) is_expr: bool,
+    pub(super) in_loop_body: bool,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub(crate) enum CallKind {
+    Pat,
+    Mac,
+    Expr,
+}
 /// `CompletionContext` is created early during completion to figure out, where
 /// exactly is the cursor, syntax-wise.
 #[derive(Debug)]
@@ -45,14 +68,13 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) krate: Option<hir::Crate>,
     pub(super) expected_name: Option<NameOrNameRef>,
     pub(super) expected_type: Option<Type>,
-    pub(super) name_ref_syntax: Option<ast::NameRef>,
-
-    pub(super) use_item_syntax: Option<ast::Use>,
 
     /// The parent function of the cursor position if it exists.
     pub(super) function_def: Option<ast::Fn>,
     /// The parent impl of the cursor position if it exists.
     pub(super) impl_def: Option<ast::Impl>,
+    pub(super) name_ref_syntax: Option<ast::NameRef>,
+    pub(super) use_item_syntax: Option<ast::Use>,
 
     // potentially set if we are completing a lifetime
     pub(super) lifetime_syntax: Option<ast::Lifetime>,
@@ -67,29 +89,12 @@ pub(crate) struct CompletionContext<'a> {
     pub(super) completion_location: Option<ImmediateLocation>,
     pub(super) prev_sibling: Option<ImmediatePrevSibling>,
     pub(super) attribute_under_caret: Option<ast::Attr>,
+    pub(super) previous_token: Option<SyntaxToken>,
 
-    /// FIXME: `ActiveParameter` is string-based, which is very very wrong
+    pub(super) path_context: Option<PathCompletionContext>,
     pub(super) active_parameter: Option<ActiveParameter>,
-    /// A single-indent path, like `foo`. `::foo` should not be considered a trivial path.
-    pub(super) is_trivial_path: bool,
-    /// If not a trivial path, the prefix (qualifier).
-    pub(super) path_qual: Option<ast::Path>,
-    /// `true` if we are a statement or a last expr in the block.
-    pub(super) can_be_stmt: bool,
-    /// `true` if we expect an expression at the cursor position.
-    pub(super) is_expr: bool,
-    /// If this is a call (method or function) in particular, i.e. the () are already there.
-    pub(super) is_call: bool,
-    /// Like `is_call`, but for tuple patterns.
-    pub(super) is_pattern_call: bool,
-    /// If this is a macro call, i.e. the () are already there.
-    pub(super) is_macro_call: bool,
-    pub(super) is_path_type: bool,
-    pub(super) has_type_args: bool,
     pub(super) locals: Vec<(String, Local)>,
 
-    pub(super) previous_token: Option<SyntaxToken>,
-    pub(super) in_loop_body: bool,
     pub(super) incomplete_let: bool,
 
     no_completion_required: bool,
@@ -136,36 +141,27 @@ impl<'a> CompletionContext<'a> {
             original_token,
             token,
             krate,
-            lifetime_allowed: false,
             expected_name: None,
             expected_type: None,
+            function_def: None,
+            impl_def: None,
             name_ref_syntax: None,
+            use_item_syntax: None,
             lifetime_syntax: None,
             lifetime_param_syntax: None,
-            function_def: None,
-            use_item_syntax: None,
-            impl_def: None,
-            active_parameter: ActiveParameter::at(db, position),
+            lifetime_allowed: false,
             is_label_ref: false,
-            is_param: false,
             is_pat_or_const: None,
-            is_trivial_path: false,
-            path_qual: None,
-            can_be_stmt: false,
-            is_expr: false,
-            is_call: false,
-            is_pattern_call: false,
-            is_macro_call: false,
-            is_path_type: false,
-            has_type_args: false,
-            previous_token: None,
-            in_loop_body: false,
+            is_param: false,
             completion_location: None,
             prev_sibling: None,
-            no_completion_required: false,
-            incomplete_let: false,
             attribute_under_caret: None,
+            previous_token: None,
+            path_context: None,
+            active_parameter: ActiveParameter::at(db, position),
             locals,
+            incomplete_let: false,
+            no_completion_required: false,
         };
 
         let mut original_file = original_file.syntax().clone();
@@ -250,14 +246,14 @@ impl<'a> CompletionContext<'a> {
     pub(crate) fn has_dot_receiver(&self) -> bool {
         matches!(
             &self.completion_location,
-            Some(ImmediateLocation::FieldAccess { receiver, .. }) | Some(ImmediateLocation::MethodCall { receiver })
+            Some(ImmediateLocation::FieldAccess { receiver, .. }) | Some(ImmediateLocation::MethodCall { receiver,.. })
                 if receiver.is_some()
         )
     }
 
     pub(crate) fn dot_receiver(&self) -> Option<&ast::Expr> {
         match &self.completion_location {
-            Some(ImmediateLocation::MethodCall { receiver })
+            Some(ImmediateLocation::MethodCall { receiver, .. })
             | Some(ImmediateLocation::FieldAccess { receiver, .. }) => receiver.as_ref(),
             _ => None,
         }
@@ -275,11 +271,6 @@ impl<'a> CompletionContext<'a> {
         matches!(self.completion_location, Some(ImmediateLocation::ItemList))
     }
 
-    //         fn expects_value(&self) -> bool {
-    pub(crate) fn expects_expression(&self) -> bool {
-        self.is_expr
-    }
-
     pub(crate) fn has_block_expr_parent(&self) -> bool {
         matches!(self.completion_location, Some(ImmediateLocation::BlockExpr))
     }
@@ -316,6 +307,22 @@ impl<'a> CompletionContext<'a> {
         ) || self.attribute_under_caret.is_some()
     }
 
+    pub(crate) fn expects_expression(&self) -> bool {
+        self.path_context.as_ref().map_or(false, |it| it.is_expr)
+    }
+
+    pub(crate) fn path_call_kind(&self) -> Option<CallKind> {
+        self.path_context.as_ref().and_then(|it| it.call_kind)
+    }
+
+    pub(crate) fn is_trivial_path(&self) -> bool {
+        self.path_context.as_ref().map_or(false, |it| it.is_trivial_path)
+    }
+
+    pub(crate) fn path_qual(&self) -> Option<&ast::Path> {
+        self.path_context.as_ref().and_then(|it| it.path_qual.as_ref())
+    }
+
     fn fill_impl_def(&mut self) {
         self.impl_def = self
             .sema
@@ -441,7 +448,6 @@ impl<'a> CompletionContext<'a> {
             let for_is_prev2 = for_is_prev2(syntax_element.clone());
             (fn_is_prev && !inside_impl_trait_block) || for_is_prev2
         };
-        self.in_loop_body = is_in_loop_body(syntax_element.clone());
 
         self.incomplete_let =
             syntax_element.ancestors().take(6).find_map(ast::LetStmt::cast).map_or(false, |it| {
@@ -549,10 +555,6 @@ impl<'a> CompletionContext<'a> {
         self.name_ref_syntax =
             find_node_at_offset(original_file, name_ref.syntax().text_range().start());
 
-        if matches!(self.completion_location, Some(ImmediateLocation::ItemList)) {
-            return;
-        }
-
         self.use_item_syntax =
             self.sema.token_ancestors_with_macros(self.token.clone()).find_map(ast::Use::cast);
 
@@ -568,22 +570,34 @@ impl<'a> CompletionContext<'a> {
         };
 
         if let Some(segment) = ast::PathSegment::cast(parent) {
+            let path_ctx = self.path_context.get_or_insert(PathCompletionContext {
+                call_kind: None,
+                is_trivial_path: false,
+                path_qual: None,
+                has_type_args: false,
+                is_path_type: false,
+                can_be_stmt: false,
+                is_expr: false,
+                in_loop_body: false,
+            });
+            path_ctx.in_loop_body = is_in_loop_body(name_ref.syntax());
             let path = segment.parent_path();
-            self.is_call = path
-                .syntax()
-                .parent()
-                .and_then(ast::PathExpr::cast)
-                .and_then(|it| it.syntax().parent().and_then(ast::CallExpr::cast))
-                .is_some();
-            self.is_macro_call = path.syntax().parent().and_then(ast::MacroCall::cast).is_some();
-            self.is_pattern_call =
-                path.syntax().parent().and_then(ast::TupleStructPat::cast).is_some();
 
-            self.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
-            self.has_type_args = segment.generic_arg_list().is_some();
+            if let Some(p) = path.syntax().parent() {
+                path_ctx.call_kind = match_ast! {
+                    match p {
+                        ast::PathExpr(it) => it.syntax().parent().and_then(ast::CallExpr::cast).map(|_| CallKind::Expr),
+                        ast::MacroCall(it) => it.excl_token().and(Some(CallKind::Mac)),
+                        ast::TupleStructPat(_it) => Some(CallKind::Pat),
+                        _ => None
+                    }
+                };
+            }
+            path_ctx.is_path_type = path.syntax().parent().and_then(ast::PathType::cast).is_some();
+            path_ctx.has_type_args = segment.generic_arg_list().is_some();
 
             if let Some(path) = path_or_use_tree_qualifier(&path) {
-                self.path_qual = path
+                path_ctx.path_qual = path
                     .segment()
                     .and_then(|it| {
                         find_node_with_range::<ast::PathSegment>(
@@ -601,11 +615,11 @@ impl<'a> CompletionContext<'a> {
                 }
             }
 
-            self.is_trivial_path = true;
+            path_ctx.is_trivial_path = true;
 
             // Find either enclosing expr statement (thing with `;`) or a
             // block. If block, check that we are the last expr.
-            self.can_be_stmt = name_ref
+            path_ctx.can_be_stmt = name_ref
                 .syntax()
                 .ancestors()
                 .find_map(|node| {
@@ -621,10 +635,8 @@ impl<'a> CompletionContext<'a> {
                     None
                 })
                 .unwrap_or(false);
-            self.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
+            path_ctx.is_expr = path.syntax().parent().and_then(ast::PathExpr::cast).is_some();
         }
-        self.is_call |=
-            matches!(self.completion_location, Some(ImmediateLocation::MethodCall { .. }));
     }
 }