json-joy/esm/json-ot/types/ot-string-irreversible/apply.js

Collection of libraries for building collaborative editing apps.

export const apply = (str, op) => {
    const length = op.length;
    let res = '';
    let offset = 0;
    for (let i = 0; i < length; i++) {
        const component = op[i];
        switch (typeof component) {
            case 'string':
                res += component;
                break;
            case 'number': {
                if (component > 0) {
                    const end = offset + component;
                    res += str.substring(offset, end);
                    offset = end;
                }
                else
                    offset -= component;
                break;
            }
        }
    }
    return res + str.substring(offset);
};