1  /**
 2   * Polyfill for the optional chain operator, `?.`, given previous conversion of the expression into an array of values,
 3   * descriptors, and functions.
 4   *
 5   * Adapted from Sucrase (https://github.com/alangpierce/sucrase)
 6   * See https://github.com/alangpierce/sucrase/blob/265887868966917f3b924ce38dfad01fbab1329f/src/transformers/OptionalChainingNullishTransformer.ts#L15
 7   *
 8   * @param ops Array result of expression conversion
 9   * @returns The value of the expression
10   */
11  function _optionalChain(ops) {
12    let lastAccessLHS = undefined;
13    let value = ops[0];
14    let i = 1;
15    while (i < ops.length) {
16      const op = ops[i] ;
17      const fn = ops[i + 1] ;
18      i += 2;
19      // by checking for loose equality to `null`, we catch both `null` and `undefined`
20      if ((op === 'optionalAccess' || op === 'optionalCall') && value == null) {
21        // really we're meaning to return `undefined` as an actual value here, but it saves bytes not to write it
22        return;
23      }
24      if (op === 'access' || op === 'optionalAccess') {
25        lastAccessLHS = value;
26        value = fn(value);
27      } else if (op === 'call' || op === 'optionalCall') {
28        value = fn((...args) => (value ).call(lastAccessLHS, ...args));
29        lastAccessLHS = undefined;
30      }
31    }
32    return value;
33  }
34  
35  // Sucrase version
36  // function _optionalChain(ops) {
37  //   let lastAccessLHS = undefined;
38  //   let value = ops[0];
39  //   let i = 1;
40  //   while (i < ops.length) {
41  //     const op = ops[i];
42  //     const fn = ops[i + 1];
43  //     i += 2;
44  //     if ((op === 'optionalAccess' || op === 'optionalCall') && value == null) {
45  //       return undefined;
46  //     }
47  //     if (op === 'access' || op === 'optionalAccess') {
48  //       lastAccessLHS = value;
49  //       value = fn(value);
50  //     } else if (op === 'call' || op === 'optionalCall') {
51  //       value = fn((...args) => value.call(lastAccessLHS, ...args));
52  //       lastAccessLHS = undefined;
53  //     }
54  //   }
55  //   return value;
56  // }
57  
58  export { _optionalChain };
59  //# sourceMappingURL=_optionalChain.js.map