Add CompletionRelevanceConstructorType enum and implement compute_constructor_type function

Author: mustakimali

crates/ide-completion/src/item.rs

@@ -164,8 +164,8 @@ pub struct CompletionRelevance {
     pub postfix_match: Option<CompletionRelevancePostfixMatch>,
     /// This is set for type inference results
     pub is_definite: bool,
-    /// Any other bonuses we want to add,
-    pub bonus_score: u32,
+    /// This is set for items that are constructors for the type of the impl/trait
+    pub constructor_type: Option<CompletionRelevanceConstructorType>,
 }
 
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
@@ -207,6 +207,17 @@ pub enum CompletionRelevancePostfixMatch {
     Exact,
 }
 
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum CompletionRelevanceConstructorType {
+    /// Returns the Self type of the impl/trait
+    DirectConstructor,
+    DirectConstructorWithArgs,
+    /// Returns something that indirectly constructs the `Self` type of the impl/trait e.g. `Result<Self, ()>`, `Option<Self>`
+    Constructor,
+    /// Returns a possible builder for the type
+    Builder,
+}
+
 impl CompletionRelevance {
     /// Provides a relevance score. Higher values are more relevant.
     ///
@@ -230,7 +241,7 @@ impl CompletionRelevance {
             is_private_editable,
             postfix_match,
             is_definite,
-            bonus_score,
+            constructor_type,
         } = self;
 
         // lower rank private things
@@ -273,7 +284,15 @@ impl CompletionRelevance {
             score += 10;
         }
 
-        score + bonus_score
+        score += match constructor_type {
+            Some(CompletionRelevanceConstructorType::DirectConstructor) => 3,
+            Some(CompletionRelevanceConstructorType::DirectConstructorWithArgs) => 2,
+            Some(CompletionRelevanceConstructorType::Builder) => 2,
+            Some(CompletionRelevanceConstructorType::Constructor) => 2,
+            None => 0,
+        };
+
+        score
     }
 
     /// Returns true when the score for this threshold is above

crates/ide-completion/src/render.rs

@@ -17,7 +17,7 @@ use ide_db::{
     imports::import_assets::LocatedImport,
     RootDatabase, SnippetCap, SymbolKind,
 };
-use syntax::{AstNode, SmolStr, SyntaxKind, SyntaxToken, TextRange};
+use syntax::{AstNode, SmolStr, SyntaxKind, TextRange};
 use text_edit::TextEdit;
 
 use crate::{
@@ -72,10 +72,6 @@ impl<'a> RenderContext<'a> {
         self.completion.db
     }
 
-    fn token(&self) -> &SyntaxToken {
-        &self.completion.token
-    }
-
     fn source_range(&self) -> TextRange {
         self.completion.source_range()
     }
@@ -1180,7 +1176,7 @@ fn main() { let _: m::Spam = S$0 }
                             is_private_editable: false,
                             postfix_match: None,
                             is_definite: false,
-                            bonus_score: 0,
+                            constructor_type: None,
                         },
                         trigger_call_info: true,
                     },
@@ -1207,7 +1203,7 @@ fn main() { let _: m::Spam = S$0 }
                             is_private_editable: false,
                             postfix_match: None,
                             is_definite: false,
-                            bonus_score: 0,
+                            constructor_type: None,
                         },
                         trigger_call_info: true,
                     },
@@ -1286,7 +1282,7 @@ fn foo() { A { the$0 } }
                             is_private_editable: false,
                             postfix_match: None,
                             is_definite: false,
-                            bonus_score: 0,
+                            constructor_type: None,
                         },
                     },
                 ]
@@ -2083,6 +2079,21 @@ fn foo(f: Foo) { let _: &u32 = f.b$0 }
                         kind: Method,
                         lookup: "baz",
                         detail: "fn(&self) -> u32",
+                        relevance: CompletionRelevance {
+                            exact_name_match: false,
+                            type_match: None,
+                            is_local: false,
+                            is_item_from_trait: false,
+                            is_name_already_imported: false,
+                            requires_import: false,
+                            is_op_method: false,
+                            is_private_editable: false,
+                            postfix_match: None,
+                            is_definite: false,
+                            constructor_type: Some(
+                                DirectConstructorWithArgs,
+                            ),
+                        },
                         ref_match: "&@107",
                     },
                     CompletionItem {
@@ -2156,7 +2167,7 @@ fn foo() {
                             is_private_editable: false,
                             postfix_match: None,
                             is_definite: false,
-                            bonus_score: 0,
+                            constructor_type: None,
                         },
                     },
                 ]
@@ -2205,7 +2216,9 @@ fn main() {
                             is_private_editable: false,
                             postfix_match: None,
                             is_definite: false,
-                            bonus_score: 30,
+                            constructor_type: Some(
+                                DirectConstructor,
+                            ),
                         },
                         ref_match: "&@92",
                     },

crates/ide-completion/src/render/function.rs

@@ -8,7 +8,10 @@ use syntax::{AstNode, SmolStr};
 
 use crate::{
     context::{CompletionContext, DotAccess, DotAccessKind, PathCompletionCtx, PathKind},
-    item::{Builder, CompletionItem, CompletionItemKind, CompletionRelevance},
+    item::{
+        Builder, CompletionItem, CompletionItemKind, CompletionRelevance,
+        CompletionRelevanceConstructorType,
+    },
     render::{compute_exact_name_match, compute_ref_match, compute_type_match, RenderContext},
     CallableSnippets,
 };
@@ -105,7 +108,7 @@ fn render(
         },
         exact_name_match: compute_exact_name_match(completion, &call),
         is_op_method,
-        bonus_score: calculate_bonus(&ctx, func, db),
+        constructor_type: compute_constructor_type(&ctx, func, db),
         ..ctx.completion_relevance()
     });
 
@@ -154,32 +157,30 @@ fn render(
     item
 }
 
-/// When typing `::` of a type, the preferred order is:
-/// * Constructors: new like functions to be able to create the type,
-/// * Builder Methods,
-/// * Constructors that take args: Any other function that creates Self
-/// * Regular methods & Associated functions
-///
-fn calculate_bonus(ctx: &RenderContext<'_>, func: hir::Function, db: &dyn HirDatabase) -> u32 {
-    if ctx.token().kind() != syntax::SyntaxKind::COLON2 || func.self_param(db).is_some() {
-        return 0;
+fn compute_constructor_type(
+    ctx: &RenderContext<'_>,
+    func: hir::Function,
+    db: &dyn HirDatabase,
+) -> Option<CompletionRelevanceConstructorType> {
+    if func.as_assoc_item(ctx.db()).is_none() {
+        return None;
     }
 
-    let mut bonus = 0;
-
     let has_args = !func.assoc_fn_params(db).is_empty();
     let ret_type = func.ret_type(db);
+
     if !has_args && !ret_type.is_unit() {
         // fn() -> A
-        bonus += 30;
+        Some(CompletionRelevanceConstructorType::DirectConstructor)
     } else if has_args && !ret_type.is_unit() {
         // fn(..) -> A
-        bonus += 20;
+        Some(CompletionRelevanceConstructorType::DirectConstructorWithArgs)
     } else if !has_args && ret_type.display(db).to_string().ends_with("Builder") {
         // -> [..]Builder
-        bonus += 10;
+        Some(CompletionRelevanceConstructorType::Builder)
+    } else {
+        None
     }
-    bonus
 }
 
 pub(super) fn add_call_parens<'b>(