[CodeCompletion] Display mapped type for subscript result

Author: rintaro

lib/IDE/CodeCompletion.cpp

@@ -2545,6 +2545,10 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
     if (HaveDot && !IsAfterSwiftKeyPathRoot)
       return;
 
+    auto subscriptType = getTypeOfMember(SD)->getAs<AnyFunctionType>();
+    if (!subscriptType)
+      return;
+
     CommandWordsPairs Pairs;
     CodeCompletionResultBuilder Builder(
         Sink,
@@ -2563,19 +2567,17 @@ class CompletionLookup final : public swift::VisibleDeclConsumer {
     }
 
     Builder.addLeftBracket();
-    addCallArgumentPatterns(Builder,
-                            getTypeOfMember(SD)->castTo<AnyFunctionType>(),
-                            SD->getIndices(), true);
+    addCallArgumentPatterns(Builder, subscriptType, SD->getIndices(), true);
     Builder.addRightBracket();
 
     // Add a type annotation.
-    Type T = SD->getElementInterfaceType();
+    Type resultTy = subscriptType->getResult();
     if (IsDynamicLookup) {
       // Values of properties that were found on a AnyObject have
       // Optional<T> type.
-      T = OptionalType::get(T);
+      resultTy = OptionalType::get(resultTy);
     }
-    addTypeAnnotation(Builder, T);
+    addTypeAnnotation(Builder, resultTy);
   }
 
   void addNominalTypeRef(const NominalTypeDecl *NTD,

test/IDE/complete_swift_key_path.swift

@@ -53,16 +53,16 @@ let _ = \Person.#^TYPE_DOT^#
 
 let _ = \Person.friends#^ARRAY_NODOT^#
 // ARRAY-NODOT: Begin completions
-// ARRAY-NODOT-DAG: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Element#]; name=[index: Int]
+// ARRAY-NODOT-DAG: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Person#]; name=[index: Int]
 // ARRAY-NODOT-DAG: Decl[InstanceVar]/CurrNominal:      .count[#Int#]; name=count
 // ARRAY-NODOT-DAG: Decl[InstanceVar]/Super:            .first[#Person?#]; name=first
 
 let _ = \Person.friends.#^ARRAY_DOT^#
 // ARRAY-DOT: Begin completions
-// ARRAY-DOT-NOT: Decl[Subscript]/CurrNominal:        [{#Int#}][#Element#]; name=[Int]
+// ARRAY-DOT-NOT: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Element#]; name=[Int]
 // ARRAY-DOT-DAG: Decl[InstanceVar]/CurrNominal:      count[#Int#]; name=count
 // ARRAY-DOT-DAG: Decl[InstanceVar]/Super:            first[#Person?#]; name=first
-// ARRAY-DOT-NOT: Decl[Subscript]/CurrNominal:        [{#Int#}][#Element#]; name=[Int]
+// ARRAY-DOT-NOT: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Element#]; name=[Int]
 
 let _ = \Person.friends[0]#^OBJ_NODOT^#
 // OBJ-NODOT: Begin completions, 5 items
@@ -110,13 +110,13 @@ let _ = \Person.bestFriend?.itself.#^CHAIN_DOT^#
 
 let _ = \[Person]#^ARRAYTYPE_NODOT^#
 // ARRAYTYPE-NODOT: Begin completions
-// ARRAYTYPE-NODOT-DAG: Decl[Subscript]/CurrNominal:        .[{#(index): Int#}][#Element#]; name=[index: Int]
+// ARRAYTYPE-NODOT-DAG: Decl[Subscript]/CurrNominal:        .[{#(index): Int#}][#Person#]; name=[index: Int]
 // ARRAYTYPE-NODOT-DAG: Decl[InstanceVar]/CurrNominal:      .count[#Int#]; name=count
 // ARRAYTYPE-NODOT-DAG: Decl[InstanceVar]/Super:            .first[#Person?#]; name=first
 
 let _ = \[Person].#^ARRAYTYPE_DOT^#
 // ARRAYTYPE-DOT: Begin completions
-// ARRAYTYPE-DOT-DAG: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Element#]; name=[index: Int]
+// ARRAYTYPE-DOT-DAG: Decl[Subscript]/CurrNominal:        [{#(index): Int#}][#Person#]; name=[index: Int]
 // ARRAYTYPE-DOT-DAG: Decl[InstanceVar]/CurrNominal:      count[#Int#]; name=count
 // ARRAYTYPE-DOT-DAG: Decl[InstanceVar]/Super:            first[#Person?#]; name=first
 

test/IDE/complete_value_expr.swift

@@ -1890,7 +1890,7 @@ func testDeDuped2(_ x: dedupP) {
 // PROTOCOL_EXT_DEDUP_2: Begin completions, 5 items
 // PROTOCOL_EXT_DEDUP_2: Decl[InstanceMethod]/CurrNominal:   .foo()[#dedupP.T#]; name=foo()
 // PROTOCOL_EXT_DEDUP_2: Decl[InstanceVar]/CurrNominal:      .bar[#dedupP.T#]; name=bar
-// PROTOCOL_EXT_DEDUP_2: Decl[Subscript]/CurrNominal:        [{#(x): dedupP.T#}][#Self.T#]; name=[x: dedupP.T]
+// PROTOCOL_EXT_DEDUP_2: Decl[Subscript]/CurrNominal:        [{#(x): dedupP.T#}][#dedupP.T#]; name=[x: dedupP.T]
 // PROTOCOL_EXT_DEDUP_2: Keyword[self]/CurrNominal:          .self[#dedupP#]; name=self
 // PROTOCOL_EXT_DEDUP_2: End completions
 }
@@ -1899,7 +1899,7 @@ func testDeDuped3<T : dedupP where T.T == Int>(_ x: T) {
 // PROTOCOL_EXT_DEDUP_3: Begin completions, 5 items
 // PROTOCOL_EXT_DEDUP_3: Decl[InstanceMethod]/CurrNominal:   .foo()[#Int#]; name=foo()
 // PROTOCOL_EXT_DEDUP_3: Decl[InstanceVar]/CurrNominal:      .bar[#Int#]; name=bar
-// PROTOCOL_EXT_DEDUP_3: Decl[Subscript]/CurrNominal:        [{#(x): Int#}][#Self.T#]; name=[x: Int]
+// PROTOCOL_EXT_DEDUP_3: Decl[Subscript]/CurrNominal:        [{#(x): Int#}][#Int#]; name=[x: Int]
 // PROTOCOL_EXT_DEDUP_3: Keyword[self]/CurrNominal:          .self[#T#]; name=self
 // PROTOCOL_EXT_DEDUP_3: End completions
 }