cst-stringify.js 1.76 KB
'use strict';

/**
 * Stringify a CST document, token, or collection item
 *
 * Fair warning: This applies no validation whatsoever, and
 * simply concatenates the sources in their logical order.
 */
const stringify = (cst) => 'type' in cst ? stringifyToken(cst) : stringifyItem(cst);
function stringifyToken(token) {
    switch (token.type) {
        case 'block-scalar': {
            let res = '';
            for (const tok of token.props)
                res += stringifyToken(tok);
            return res + token.source;
        }
        case 'block-map':
        case 'block-seq': {
            let res = '';
            for (const item of token.items)
                res += stringifyItem(item);
            return res;
        }
        case 'flow-collection': {
            let res = token.start.source;
            for (const item of token.items)
                res += stringifyItem(item);
            for (const st of token.end)
                res += st.source;
            return res;
        }
        case 'document': {
            let res = stringifyItem(token);
            if (token.end)
                for (const st of token.end)
                    res += st.source;
            return res;
        }
        default: {
            let res = token.source;
            if ('end' in token && token.end)
                for (const st of token.end)
                    res += st.source;
            return res;
        }
    }
}
function stringifyItem({ start, key, sep, value }) {
    let res = '';
    for (const st of start)
        res += st.source;
    if (key)
        res += stringifyToken(key);
    if (sep)
        for (const st of sep)
            res += st.source;
    if (value)
        res += stringifyToken(value);
    return res;
}

exports.stringify = stringify;