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Less expensive and corrected check for broadest equivalent keys
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@ahejlsberg
ahejlsberg committed Oct 31, 2021
1 parent 5f37d89 commit 9df07a8
Showing 1 changed file with 41 additions and 35 deletions.
76 changes: 41 additions & 35 deletions src/compiler/checker.ts
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Expand Up @@ -17770,7 +17770,7 @@ namespace ts {
if (source.flags & TypeFlags.Singleton) return true;
}
if (source.flags & TypeFlags.Object && target.flags & TypeFlags.Object) {
const related = relation.get(getRelationKey(source, target, IntersectionState.None, relation));
const related = relation.get(getRelationKey(source, target, IntersectionState.None, relation, /*ignoreConstraints*/ false));
if (related !== undefined) {
return !!(related & RelationComparisonResult.Succeeded);
}
Expand Down Expand Up @@ -18670,7 +18670,8 @@ namespace ts {
if (overflow) {
return Ternary.False;
}
const id = getRelationKey(source, target, intersectionState | (inPropertyCheck ? IntersectionState.InPropertyCheck : 0), relation);
const keyIntersectionState = intersectionState | (inPropertyCheck ? IntersectionState.InPropertyCheck : 0);
const id = getRelationKey(source, target, keyIntersectionState, relation, /*ingnoreConstraints*/ false);
const entry = relation.get(id);
if (entry !== undefined) {
if (reportErrors && entry & RelationComparisonResult.Failed && !(entry & RelationComparisonResult.Reported)) {
Expand All @@ -18697,16 +18698,13 @@ namespace ts {
targetStack = [];
}
else {
// generate a key where all type parameter id positions are replaced with unconstrained type parameter ids
// this isn't perfect - nested type references passed as type arguments will muck up the indexes and thus
// prevent finding matches- but it should hit up the common cases
const broadestEquivalentId = id.split(",").map(i => i.replace(/-\d+/g, (_match, offset: number) => {
const index = length(id.slice(0, offset).match(/[-=]/g) || undefined);
return `=${index}`;
})).join(",");
// A key that starts with "*" is an indication that we have type references that reference constrained
// type parameters. For such keys we also check against the key we would have gotten if all type parameters
// were unconstrained.
const broadestEquivalentId = id.startsWith("*") ? getRelationKey(source, target, keyIntersectionState, relation, /*ignoreConstraints*/ true) : undefined;
for (let i = 0; i < maybeCount; i++) {
// If source and target are already being compared, consider them related with assumptions
if (id === maybeKeys[i] || broadestEquivalentId === maybeKeys[i]) {
if (id === maybeKeys[i] || broadestEquivalentId && broadestEquivalentId === maybeKeys[i]) {
return Ternary.Maybe;
}
}
Expand Down Expand Up @@ -20261,47 +20259,55 @@ namespace ts {
return isNonDeferredTypeReference(type) && some(getTypeArguments(type), t => !!(t.flags & TypeFlags.TypeParameter) || isTypeReferenceWithGenericArguments(t));
}

/**
* getTypeReferenceId(A<T, number, U>) returns "111=0-12=1"
* where A.id=111 and number.id=12
*/
function getTypeReferenceId(type: TypeReference, typeParameters: Type[], depth = 0) {
let result = "" + type.target.id;
for (const t of getTypeArguments(type)) {
if (isUnconstrainedTypeParameter(t)) {
let index = typeParameters.indexOf(t);
if (index < 0) {
index = typeParameters.length;
typeParameters.push(t);
function getGenericTypeReferenceRelationKey(source: TypeReference, target: TypeReference, postFix: string, ignoreConstraints: boolean) {
const typeParameters: Type[] = [];
let constraintMarker = "";
const sourceId = getTypeReferenceId(source, 0);
const targetId = getTypeReferenceId(target, 0);
return `${constraintMarker}${sourceId},${targetId}${postFix}`;
// getTypeReferenceId(A<T, number, U>) returns "111=0-12=1"
// where A.id=111 and number.id=12
function getTypeReferenceId(type: TypeReference, depth = 0) {
let result = "" + type.target.id;
for (const t of getTypeArguments(type)) {
if (t.flags & TypeFlags.TypeParameter) {
if (ignoreConstraints || isUnconstrainedTypeParameter(t)) {
let index = typeParameters.indexOf(t);
if (index < 0) {
index = typeParameters.length;
typeParameters.push(t);
}
result += "=" + index;
continue;
}
// We mark type references that reference constrained type parameters such that we know to obtain
// and look for a "broadest equivalent key" in the cache.
constraintMarker = "*";
}
else if (depth < 4 && isTypeReferenceWithGenericArguments(t)) {
result += "<" + getTypeReferenceId(t as TypeReference, depth + 1) + ">";
continue;
}
result += "=" + index;
}
else if (depth < 4 && isTypeReferenceWithGenericArguments(t)) {
result += "<" + getTypeReferenceId(t as TypeReference, typeParameters, depth + 1) + ">";
}
else {
result += "-" + t.id;
}
return result;
}
return result;
}

/**
* To improve caching, the relation key for two generic types uses the target's id plus ids of the type parameters.
* For other cases, the types ids are used.
*/
function getRelationKey(source: Type, target: Type, intersectionState: IntersectionState, relation: ESMap<string, RelationComparisonResult>) {
function getRelationKey(source: Type, target: Type, intersectionState: IntersectionState, relation: ESMap<string, RelationComparisonResult>, ignoreConstraints: boolean) {
if (relation === identityRelation && source.id > target.id) {
const temp = source;
source = target;
target = temp;
}
const postFix = intersectionState ? ":" + intersectionState : "";
if (isTypeReferenceWithGenericArguments(source) && isTypeReferenceWithGenericArguments(target)) {
const typeParameters: Type[] = [];
return getTypeReferenceId(source as TypeReference, typeParameters) + "," + getTypeReferenceId(target as TypeReference, typeParameters) + postFix;
}
return source.id + "," + target.id + postFix;
return isTypeReferenceWithGenericArguments(source) && isTypeReferenceWithGenericArguments(target) ?
getGenericTypeReferenceRelationKey(source as TypeReference, target as TypeReference, postFix, ignoreConstraints) :
`${source.id},${target.id}${postFix}`;
}

// Invoke the callback for each underlying property symbol of the given symbol and return the first
Expand Down

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