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Property track mapped types in combined type mappers

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This commit is contained in:
Anders Hejlsberg
2017-01-08 15:21:09 -08:00
parent 5b075ff924
commit 523aca204a
1 changed files with 14 additions and 16 deletions
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30
src/compiler/checker.ts
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@@ -4606,7 +4606,7 @@ namespace ts {
// Create a mapper from T to the current iteration type constituent. Then, if the
// mapped type is itself an instantiated type, combine the iteration mapper with the
// instantiation mapper.
const iterationMapper = createUnaryTypeMapper(typeParameter, t);
const iterationMapper = createTypeMapper([typeParameter], [t]);
const templateMapper = type.mapper ? combineTypeMappers(type.mapper, iterationMapper) : iterationMapper;
const propType = instantiateType(templateType, templateMapper);
// If the current iteration type constituent is a string literal type, create a property.
@@ -4666,7 +4666,7 @@ namespace ts {
}
function getErasedTemplateTypeFromMappedType(type: MappedType) {
return instantiateType(getTemplateTypeFromMappedType(type), createUnaryTypeMapper(getTypeParameterFromMappedType(type), anyType));
return instantiateType(getTemplateTypeFromMappedType(type), createTypeEraser([getTypeParameterFromMappedType(type)]));
}
function isGenericMappedType(type: Type) {
@@ -6135,7 +6135,7 @@ namespace ts {
error(accessExpression, Diagnostics.Index_signature_in_type_0_only_permits_reading, typeToString(type));
return unknownType;
}
const mapper = createUnaryTypeMapper(getTypeParameterFromMappedType(type), indexType);
const mapper = createTypeMapper([getTypeParameterFromMappedType(type)], [indexType]);
const templateMapper = type.mapper ? combineTypeMappers(type.mapper, mapper) : mapper;
return instantiateType(getTemplateTypeFromMappedType(type), templateMapper);
}
@@ -6502,16 +6502,16 @@ namespace ts {
return <T>instantiations[type.id] || (instantiations[type.id] = instantiator(type, mapper));
}
function createUnaryTypeMapper(source: Type, target: Type): TypeMapper {
return t => t === source ? target : t;
function makeUnaryTypeMapper(source: Type, target: Type) {
return (t: Type) => t === source ? target : t;
}
function createBinaryTypeMapper(source1: Type, target1: Type, source2: Type, target2: Type): TypeMapper {
return t => t === source1 ? target1 : t === source2 ? target2 : t;
function makeBinaryTypeMapper(source1: Type, target1: Type, source2: Type, target2: Type) {
return (t: Type) => t === source1 ? target1 : t === source2 ? target2 : t;
}
function createArrayTypeMapper(sources: Type[], targets: Type[]): TypeMapper {
return t => {
function makeArrayTypeMapper(sources: Type[], targets: Type[]) {
return (t: Type) => {
for (let i = 0; i < sources.length; i++) {
if (t === sources[i]) {
return targets ? targets[i] : anyType;
@@ -6522,11 +6522,9 @@ namespace ts {
}
function createTypeMapper(sources: Type[], targets: Type[]): TypeMapper {
const count = sources.length;
const mapper: TypeMapper =
count == 1 ? createUnaryTypeMapper(sources[0], targets ? targets[0] : anyType) :
count == 2 ? createBinaryTypeMapper(sources[0], targets ? targets[0] : anyType, sources[1], targets ? targets[1] : anyType) :
createArrayTypeMapper(sources, targets);
const mapper: TypeMapper = sources.length === 1 ? makeUnaryTypeMapper(sources[0], targets ? targets[0] : anyType) :
sources.length === 2 ? makeBinaryTypeMapper(sources[0], targets ? targets[0] : anyType, sources[1], targets ? targets[1] : anyType) :
makeArrayTypeMapper(sources, targets);
mapper.mappedTypes = sources;
return mapper;
}
@@ -6560,7 +6558,7 @@ namespace ts {
function combineTypeMappers(mapper1: TypeMapper, mapper2: TypeMapper): TypeMapper {
const mapper: TypeMapper = t => instantiateType(mapper1(t), mapper2);
mapper.mappedTypes = mapper1.mappedTypes;
mapper.mappedTypes = concatenate(mapper1.mappedTypes, mapper2.mappedTypes);
return mapper;
}
@@ -6662,7 +6660,7 @@ namespace ts {
if (typeVariable !== mappedTypeVariable) {
return mapType(mappedTypeVariable, t => {
if (isMappableType(t)) {
const replacementMapper = createUnaryTypeMapper(typeVariable, t);
const replacementMapper = createTypeMapper([typeVariable], [t]);
const combinedMapper = mapper.mappedTypes && mapper.mappedTypes.length === 1 ? replacementMapper : combineTypeMappers(replacementMapper, mapper);
combinedMapper.mappedTypes = mapper.mappedTypes;
return instantiateMappedObjectType(type, combinedMapper);