parjs/internal/parsers/char-where.js

A parser-combinator library for JavaScript.

"use strict";
/**
 * @module parjs
 */
/** */
Object.defineProperty(exports, "__esModule", { value: true });
const result_1 = require("../result");
const parser_1 = require("../parser");
const defaultFailure = {
    kind: "Soft",
    reason: "expecting a character fulfilling a predicate"
};
/**
 * Returns a parser that parses a single character fulfilling `predicate`.
 * @param predicate The predicate the character has to fulfill.
 */
function charWhere(predicate) {
    return new class CharWhere extends parser_1.ParjserBase {
        constructor() {
            super(...arguments);
            this.type = "charWhere";
            this.expecting = "expecting a character matching a predicate";
        }
        _apply(ps) {
            let { position, input } = ps;
            if (position >= input.length) {
                ps.kind = result_1.ResultKind.SoftFail;
                ps.reason = "expecting a character";
                return;
            }
            let curChar = input[position];
            let result = predicate(curChar, ps.userState);
            if (result !== true) {
                ps.reason = result.reason || this.expecting;
                ps.kind = result.kind || "Soft";
                return;
            }
            ps.value = curChar;
            ps.position++;
            ps.kind = result_1.ResultKind.Ok;
        }
    }();
}
exports.charWhere = charWhere;

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