Function createIterationTypes

test/fixtures/snapshot/typescript.js:83094–83117

(yieldType, returnType, nextType)

            return iterationTypes && iterationTypes[getIterationTypesKeyFromIterationTypeKind(typeKind)];
        }
        function createIterationTypes(yieldType, returnType, nextType) {
            // `yieldType` and `returnType` are defaulted to `neverType` they each will be combined
            // via `getUnionType` when merging iteration types. `nextType` is defined as `unknownType`
            // as it is combined via `getIntersectionType` when merging iteration types.
            if (yieldType === void 0) { yieldType = neverType; }
            if (returnType === void 0) { returnType = neverType; }
            if (nextType === void 0) { nextType = unknownType; }
            // Use the cache only for intrinsic types to keep it small as they are likely to be
            // more frequently created (i.e. `Iterator<number, void, unknown>`). Iteration types
            // are also cached on the type they are requested for, so we shouldn't need to maintain
            // the cache for less-frequently used types.
            if (yieldType.flags & 67359327 /* TypeFlags.Intrinsic */ &&
                returnType.flags & (1 /* TypeFlags.Any */ | 131072 /* TypeFlags.Never */ | 2 /* TypeFlags.Unknown */ | 16384 /* TypeFlags.Void */ | 32768 /* TypeFlags.Undefined */) &&
                nextType.flags & (1 /* TypeFlags.Any */ | 131072 /* TypeFlags.Never */ | 2 /* TypeFlags.Unknown */ | 16384 /* TypeFlags.Void */ | 32768 /* TypeFlags.Undefined */)) {
                var id = getTypeListId([yieldType, returnType, nextType]);
                var iterationTypes = iterationTypesCache.get(id);
                if (!iterationTypes) {
                    iterationTypes = { yieldType: yieldType, returnType: returnType, nextType: nextType };
                    iterationTypesCache.set(id, iterationTypes);
                }
                return iterationTypes;
            }
            return { yieldType: yieldType, returnType: returnType, nextType: nextType };
        }
        /**
         * Combines multiple `IterationTypes` records.
         *