Add IntRange type for ColorIndex #4618
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| function isValidColorIndex(value: number): value is ColorIndex { | ||
| return 0 <= value && value < 259; | ||
| } |
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@jerch should this be < 256 instead? If so what would be a good name for this color index sub-range? IsValidInputColorIndex or something?
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Yes, for colors the index is only 0..255, so its better to test for that range in during input. The fg/bg/cursor entries on top are an amalgamation, so the events and methods dont need re-declaration and/or branching.
src/common/Types.d.ts
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| : Enumerate<N, [...Acc, Acc['length']]>; | ||
| type IntRange<F extends number, T extends number> = Exclude<Enumerate<T>, Enumerate<F>>; | ||
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| type ColorIndex = IntRange<0, 259>; // number from 0 to 258 |
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Would it be clearer to limit ColorIndex here to 0..255, and to merge into a super type with the fg/bg/cursor values in a second step? Also the test function above can then refer to that narrower ColorIndex type.
jerch
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jerch
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LGTM, beside the left-over doubled change check below.
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Fixes #4614