2174: todo:
2175: | TODO STRING SEMI { `AST_nop (rstoken $1 $3, snd $2) }
2176: | TODO SEMI { `AST_nop (rstoken $1 $2, "") }
2177:
The placed holder is used to denote an incomplete section of code.
A string may be included after the 'todo' keyword to serve as a reminder
of the programmers intentions.