@thi.ng/parse/combinators/alt.js

Purely functional parser combinators & AST generation for generic inputs

import { string } from "../prims/string.js";
import { discard } from "../xform/discard.js";
const alt = (parsers) => (ctx) => {
  if (ctx.done) return false;
  for (let i = 0, n = parsers.length; i < n; i++) {
    if (parsers[i](ctx)) {
      return true;
    }
  }
  return false;
};
const altS = (strings) => alt(strings.map((x) => string(x)));
const altD = (parsers) => discard(alt(parsers));
export {
  alt,
  altD,
  altS
};