Having literals operations returning literals

[npenin]

Search Terms

enumassignmentcompat5.ts, ts2535

Suggestion

Currently, operations between literals are not considered as literals. It would bring much more flexibility to have this feature.

Use Cases

Operations on literals could help having better declarations and would help having more complex enums

Examples

// extract of enumassignmentcompat5.ts (which is not anymore in the repo BTW)
enum E {
    A, B, C
}
enum Computed {
    A = 1 << 1,
    B = 1 << 2,
    C = 1 << 3,
}
let ca: Computed.A = 1; // ok, because 1( left hand side operand) and 1 (right hand side operand) are literals, therefore, 1<<1 is also a literal.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[NN---]

#15645 #26382

[weswigham]

See #15645 #26382 - thanks @NN---

[npenin]

indeed, thanks. It at least gives a new use case ;)