tdmul/parser.js

Transfer Data Mark-Up Language - Read, write, and manipulate TDMUL files

class Parser {
    constructor(tokens) {
        this.tokens = tokens;
        this.index = 0;
        this.references = {};
    }

    parse() {
        const result = {};
        while (this.index < this.tokens.length) {
            const token = this.tokens[this.index];

            if (!token.value) {
                this.index++;
                continue;
            }

            if (token.value.endsWith("::")) {
                const sectionName = token.value.slice(0, -2).trim();
                this.index++;
                result[sectionName] = this.parseSection(token.indent + 4);
            } else {
                this.index++;
            }
        }
        return result;
    }

    parseSection(baseIndent) {
        const items = [];
        while (this.index < this.tokens.length) {
            const token = this.tokens[this.index];

            if (token.indent < baseIndent) break;
            if (!token.value) { this.index++; continue; }

            if (token.value.endsWith(":")) {
                const key = token.value.slice(0, -1).trim();
                this.index++;
                const item = this.parseItem(baseIndent + 4);
                items.push({ [key]: item });
            } else {
                this.index++;
            }
        }
        return items;
    }

    parseItem(baseIndent) {
        const obj = {};
        while (this.index < this.tokens.length) {
            const token = this.tokens[this.index];

            if (token.indent < baseIndent) break;
            if (!token.value) { this.index++; continue; }

            const line = token.value.trim();
            if (line.includes("=")) {
                let [key, value] = line.split("=");
                key = key.trim();
                value = value.trim();

                if (value.startsWith("&")) {
                    const refName = value.slice(1);
                    value = this.references[refName] ?? null;
                } else {
                    value = this.autoCast(value);
                }

                obj[key] = value;

                if (key.startsWith("&")) this.references[key.slice(1)] = value;
            }

            this.index++;
        }
        return obj;
    }

    autoCast(value) {
        if (value.startsWith("[") && value.endsWith("]")) {
            const inner = value.slice(1, -1).trim();
            if (!inner) return [];
            return inner.split(",").map(v => this.autoCast(v.trim()));
        }

        if (value === "true") return true;
        if (value === "false") return false;

        if (!isNaN(value)) return Number(value);

        return value;
    }
}

module.exports = Parser;