@gmod/vcf/esm/parseMetaString.js

High performance streaming Variant Call Format (VCF) parser in pure JavaScript

function customSplit(str) {
    const result = [];
    const chars = [];
    let inQuotes = false;
    let inBrackets = false;
    const strLen = str.length;
    for (let i = 0; i < strLen; i++) {
        const char = str[i] ?? '';
        if (char === '"') {
            inQuotes = !inQuotes;
            chars.push(char);
        }
        else if (char === '[') {
            inBrackets = true;
            chars.push(char);
        }
        else if (char === ']') {
            inBrackets = false;
            chars.push(char);
        }
        else if (char === ',' && !inQuotes && !inBrackets) {
            result.push(chars.join('').trim());
            chars.length = 0;
        }
        else {
            chars.push(char);
        }
    }
    if (chars.length > 0) {
        result.push(chars.join('').trim());
    }
    return result;
}
function splitFirst(str, split) {
    const index = str.indexOf(split);
    return [str.slice(0, index), str.slice(index + 1)];
}
export function parseStructuredMetaVal(metaVal) {
    const keyVals = parseMetaString(metaVal);
    const id = keyVals.ID;
    delete keyVals.ID;
    if ('Number' in keyVals) {
        const n = Number(keyVals.Number);
        if (!Number.isNaN(n)) {
            keyVals.Number = n;
        }
    }
    return [id, keyVals];
}
export function parseMetaString(metaString) {
    const inside = metaString.slice(1, -1);
    const parts = customSplit(inside);
    const result = {};
    for (const f of parts) {
        const [key, val] = splitFirst(f, '=');
        if (val && val.startsWith('[') && val.endsWith(']')) {
            result[key] = val
                .slice(1, -1)
                .split(',')
                .map(s => s.trim());
        }
        else if (val && val.startsWith('"') && val.endsWith('"')) {
            result[key] = val.slice(1, -1);
        }
        else {
            result[key] = val;
        }
    }
    return result;
}
//# sourceMappingURL=parseMetaString.js.map