Ep.explodeViaTempVar = function()

in packages/transform/src/emit.js [917:949]

• 18 lines of code
• 7 McCabe index (conditional complexity)

Ep.explodeViaTempVar = function(tempVar, childPath, hasLeapingChildren, ignoreChildResult) {
  assert.ok(
    !ignoreChildResult || !tempVar,
    "Ignoring the result of a child expression but forcing it to " +
      "be assigned to a temporary variable?"
  );
  const t = util.getTypes();

  let result = this.explodeExpression(childPath, ignoreChildResult);

  if (ignoreChildResult) {
    // Side effects already emitted above.

  } else if (tempVar || (hasLeapingChildren &&
                          !t.isLiteral(result))) {
    // If tempVar was provided, then the result will always be assigned
    // to it, even if the result does not otherwise need to be assigned
    // to a temporary variable.  When no tempVar is provided, we have
    // the flexibility to decide whether a temporary variable is really
    // necessary.  Unfortunately, in general, a temporary variable is
    // required whenever any child contains a yield expression, since it
    // is difficult to prove (at all, let alone efficiently) whether
    // this result would evaluate to the same value before and after the
    // yield (see #206).  One narrow case where we can prove it doesn't
    // matter (and thus we do not need a temporary variable) is when the
    // result in question is a Literal value.
    result = this.emitAssign(
      tempVar || this.makeTempVar(),
      result
    );
  }
  return result;
};