21 lines
994 B
JavaScript
21 lines
994 B
JavaScript
import { nat } from './nat.js';
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import { indexToMappedConstantMapperFor, indexToMappedConstantUnmapperFor, } from './_internals/mappers/IndexToMappedConstant.js';
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import { Error } from '../utils/globals.js';
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function computeNumChoices(options) {
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if (options.length === 0)
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throw new Error(`fc.mapToConstant expects at least one option`);
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let numChoices = 0;
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for (let idx = 0; idx !== options.length; ++idx) {
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if (options[idx].num < 0)
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throw new Error(`fc.mapToConstant expects all options to have a number of entries greater or equal to zero`);
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numChoices += options[idx].num;
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}
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if (numChoices === 0)
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throw new Error(`fc.mapToConstant expects at least one choice among options`);
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return numChoices;
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}
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export function mapToConstant(...entries) {
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const numChoices = computeNumChoices(entries);
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return nat({ max: numChoices - 1 }).map(indexToMappedConstantMapperFor(entries), indexToMappedConstantUnmapperFor(entries));
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}
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