Limitations

• What is a packrat parser not good for?

  • General CFG parsing: e.g., ambiguous grammars
    • (because of “at-most-one result” limitation)
  • Parsing highly “stateful” syntax: e.g., C, C++
    • (memoization depends on statelessness)
  • Parsing in minimal space
    • (LL/LR parser grows with stack depth, not input size)