parjs/internal/combinators/or.js

A parser-combinator library for JavaScript.

"use strict";
/**
 * @module parjs/combinators
 */
/** */
Object.defineProperty(exports, "__esModule", { value: true });
const result_1 = require("../result");
const scalar_converter_1 = require("../scalar-converter");
const combinator_1 = require("./combinator");
const parser_1 = require("../parser");
function or(...alts) {
    let resolvedAlts = alts.map(x => scalar_converter_1.ScalarConverter.convert(x));
    return combinator_1.defineCombinator(source => {
        resolvedAlts.splice(0, 0, source);
        let altNames = resolvedAlts.map(x => x.type);
        return new class Or extends parser_1.ParjserBase {
            constructor() {
                super(...arguments);
                this.type = "or";
                this.expecting = `expecting one of: ${altNames.join(", ")}`;
            }
            _apply(ps) {
                let { position } = ps;
                for (let i = 0; i < resolvedAlts.length; i++) {
                    // go over each alternative.
                    let cur = resolvedAlts[i];
                    // apply it on the current state.
                    cur.apply(ps);
                    if (ps.isOk) {
                        // if success, return. The PS records the result.
                        return;
                    }
                    else if (ps.isSoft) {
                        // backtrack to the original position and try again.
                        ps.position = position;
                    }
                    else {
                        // if failure, return false,
                        return;
                    }
                }
                ps.kind = result_1.ResultKind.SoftFail;
            }
        }();
    });
}
exports.or = or;

//# sourceMappingURL=or.js.map