90 lines
1.5 KiB
TypeScript
90 lines
1.5 KiB
TypeScript
// @strictNullChecks: true
|
|
|
|
let zero: 0 = 0;
|
|
let one: 1 = 1;
|
|
let two: 2 = 2;
|
|
let oneOrTwo: 1 | 2 = <1 | 2>1;
|
|
|
|
function f1(x: 0 | 1 | 2) {
|
|
switch (x) {
|
|
case zero:
|
|
x;
|
|
break;
|
|
case one:
|
|
x;
|
|
break;
|
|
case two:
|
|
x;
|
|
break;
|
|
default:
|
|
x;
|
|
}
|
|
}
|
|
|
|
function f2(x: 0 | 1 | 2) {
|
|
switch (x) {
|
|
case zero:
|
|
x;
|
|
break;
|
|
case oneOrTwo:
|
|
x;
|
|
break;
|
|
default:
|
|
x;
|
|
}
|
|
}
|
|
|
|
type Falsy = false | 0 | "" | null | undefined;
|
|
|
|
function f3(x: Falsy) {
|
|
if (x) {
|
|
x;
|
|
}
|
|
else {
|
|
x;
|
|
}
|
|
}
|
|
|
|
function f4(x: 0 | 1 | true | string) {
|
|
switch (x) {
|
|
case 0:
|
|
x;
|
|
break;
|
|
case 1:
|
|
x;
|
|
break;
|
|
case "abc":
|
|
case "def":
|
|
x;
|
|
break;
|
|
case null:
|
|
x;
|
|
break;
|
|
case undefined:
|
|
x;
|
|
break;
|
|
default:
|
|
x;
|
|
}
|
|
}
|
|
|
|
function f5(x: string | number | boolean) {
|
|
switch (x) {
|
|
case "abc":
|
|
x;
|
|
break;
|
|
case 0:
|
|
case 1:
|
|
x;
|
|
break;
|
|
case true:
|
|
x;
|
|
break;
|
|
case "hello":
|
|
case 123:
|
|
x;
|
|
break;
|
|
default:
|
|
x;
|
|
}
|
|
} |