Delayed semantic actions in Yakker
Trevor Jim, Yitzhak Mandelbaum · 2011
Yakker is a parser generator that supports semantic actions, lexical binding of semantic values, and speculative parsing techniques such as backtracking and context-free lookahead. To avoid executing semantic actions in speculative parses that will eventually be discarded, we divide parsing into two conceptually independent phases. In the first (early) phase, the parser explores multiple possible parse trees without executing semantic actions. The second (late) phase executes the delayed semantic actions once the first phase has determined they are necessary. Execution of the two phases can be overlapped.