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Addressing CR feedback

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unknown 2015-04-14 14:51:08 -07:00
parent f33acf8ba4
commit 9a2846ef72
1 changed files with 4 additions and 2 deletions
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6
src/compiler/checker.ts
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@ -3584,7 +3584,8 @@ module ts {
// The noSubtypeReduction flag is there because it isn't possible to always do subtype reduction. The flag
// is true when creating a union type from a type node and when instantiating a union type. In both of those
// cases subtype reduction has to be deferred to properly support recursive union types.
// cases subtype reduction has to be deferred to properly support recursive union types. For example, a
// type alias of the form "type Item = string | (() => Item)" cannot be reduced during its declaration.
function getUnionType(types: Type[], noSubtypeReduction?: boolean): Type {
if (types.length === 0) {
return emptyObjectType;
@ -3615,8 +3616,9 @@ module ts {
}
function getReducedTypeOfUnionType(type: UnionType): Type {
// If union type was created without subtype reduction, perform the deferred reduction now
if (!type.reducedType) {
type.reducedType = getUnionType(type.types);
type.reducedType = getUnionType(type.types, /*noSubtypeReduction*/ false);
}
return type.reducedType;
}