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24 lines
502 B
JavaScript
24 lines
502 B
JavaScript
"use strict";
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const { NoMatch } = require("../symbols");
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module.exports = function* either(instruction, state, context) {
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let { options } = instruction;
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for (let option of options) {
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let result = yield option;
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if (result === NoMatch) {
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// Restore index and try again with the next option
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state.currentIndex = context.startIndex;
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continue;
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} else {
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// Don't restore index; the match has been consumed
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return result;
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}
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}
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// None of the options matched
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return NoMatch;
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};
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