handling local variable declaration
updating remaining TODOs
The declareVariable method solves this problem.
implemented break & continue
correctly implemented labeled break statement
compound assignment operator is now handled
factored out a common utility
added another overload with no arguments
Handled async function.

Since the code is kind of long, performance improvement is not worth the cost of maintaining multiple overloaded versions
doc improvement
added x++, x--, etc
doc improvement
redone the function call in a modern style
unified constructor call to the new function call scheme
supported constructor call
a test case for a function call that takes no arguments
a test case for a workflow method calling another workflow method