TypeScript/tests/baselines/reference/contextualSignatureInstantiation3.js
Anders Hejlsberg d85df9e9fa Addressing CR feedback.
Adding comment to explain source type instantiation.
Adding a test case.
2014-07-22 10:54:20 -07:00

43 lines
921 B
JavaScript

//// [contextualSignatureInstantiation3.ts]
function map<T, U>(items: T[], f: (x: T) => U): U[]{
return items.map(f);
}
function identity<T>(x: T) {
return x;
}
function singleton<T>(x: T) {
return [x];
}
var xs = [1, 2, 3];
// Have compiler check that we get the correct types
var v1: number[];
var v1 = xs.map(identity); // Error if not number[]
var v1 = map(xs, identity); // Error if not number[]
var v2: number[][];
var v2 = xs.map(singleton); // Error if not number[][]
var v2 = map(xs, singleton); // Error if not number[][]
//// [contextualSignatureInstantiation3.js]
function map(items, f) {
return items.map(f);
}
function identity(x) {
return x;
}
function singleton(x) {
return [x];
}
var xs = [1, 2, 3];
var v1;
var v1 = xs.map(identity);
var v1 = map(xs, identity);
var v2;
var v2 = xs.map(singleton);
var v2 = map(xs, singleton);