@adguard/agtree/dist/parser/misc/parameter-list-parser.js

Tool set for working with adblock filter lists

/*
 * AGTree v3.2.2 (build date: Tue, 08 Jul 2025 13:39:47 GMT)
 * (c) 2025 Adguard Software Ltd.
 * Released under the MIT license
 * https://github.com/AdguardTeam/tsurlfilter/tree/master/packages/agtree#readme
 */
import { StringUtils } from '../../utils/string.js';
import { COMMA } from '../../utils/constants.js';
import { defaultParserOptions } from '../options.js';
import { BaseParser } from '../base-parser.js';
import { ValueParser } from './value-parser.js';

/**
 * Parser for parameter lists.
 */
class ParameterListParser extends BaseParser {
    /**
     * Parses a raw parameter list.
     *
     * @param raw Raw input to parse.
     * @param options Global parser options.
     * @param baseOffset Starting offset of the input. Node locations are calculated relative to this offset.
     * @param separator Separator character (default: comma)
     * @returns Parameter list AST
     */
    static parse(raw, options = defaultParserOptions, baseOffset = 0, separator = COMMA) {
        // Prepare the parameter list node
        const params = {
            type: 'ParameterList',
            children: [],
        };
        const { length } = raw;
        if (options.isLocIncluded) {
            params.start = baseOffset;
            params.end = baseOffset + length;
        }
        let offset = 0;
        // Parse parameters: skip whitespace before and after each parameter, and
        // split parameters by the separator character.
        while (offset < length) {
            // Skip whitespace before parameter
            offset = StringUtils.skipWS(raw, offset);
            // Parameter may only contain whitespace
            // In this case, we reached the end of the parameter list
            if (raw[offset] === separator || offset === length) {
                // Add a null for empty parameter
                params.children.push(null);
                // Skip separator
                offset += 1;
            }
            else {
                // Get parameter start position
                const paramStart = offset;
                // Get next unescaped separator position
                const nextSeparator = StringUtils.findUnescapedNonStringNonRegexChar(raw, separator, offset);
                // Get parameter end position
                const paramEnd = nextSeparator !== -1
                    ? StringUtils.skipWSBack(raw, nextSeparator - 1)
                    : StringUtils.skipWSBack(raw);
                // Add parameter to the list
                const param = ValueParser.parse(raw.slice(paramStart, paramEnd + 1), options, baseOffset + paramStart);
                params.children.push(param);
                // Set offset to the next separator position + 1
                offset = nextSeparator !== -1 ? nextSeparator + 1 : length;
            }
        }
        // If the last character was a separator, add an additional null parameter
        if (raw[length - 1] === separator) {
            params.children.push(null);
        }
        return params;
    }
}

export { ParameterListParser };