In this paper, we present an efficient, functional, and formally verified parsing algorithm for LL(1) context-free expressions based on the concept of derivatives of formal languages.
Parsing with derivatives is an elegant parsing technique, which, in the general case, suffers from cubic worst-case time complexity and slow performance in practice.
We specialise the parsing with derivatives algorithm to LL(1) context-free expressions, where alternatives can be chosen given a single token of lookahead.
We formalise the notion of LL(1) expressions and show how to efficiently check the LL(1) property.
Next, we present a novel linear-time parsing with derivatives algorithm for LL(1) expressions operating on a zipper-inspired data structure.
We prove the algorithm correct in Coq and present an implementation as a part of Scallion, a parser combinators framework in Scala with enumeration and pretty printing capabilities.
Conference DayFri 19 JunDisplayed time zone: Pacific Time (US & Canada) change
06:20 - 07:40 | Parsing, Debugging, and Code SearchPLDI Research Papers at PLDI Research Papers live stream Chair(s): Dan BarowyWilliams College | ||
06:20 20mTalk | Faster General Parsing through Context-Free Memoization PLDI Research Papers Grzegorz HermanJagiellonian University, Poland | ||
06:40 20mTalk | Zippy LL(1) Parsing with Derivatives PLDI Research Papers | ||
07:00 20mTalk | Debug Information Validation for Optimized Code PLDI Research Papers Yuanbo LiGeorgia Institute of Technology, USA, Shuo DingGeorgia Institute of Technology, USA, Qirun ZhangGeorgia Institute of Technology, USA, Davide ItalianoApple, USA | ||
07:20 20mTalk | Semantic Code Search via Equational Reasoning PLDI Research Papers Varot PremtoonMassachusetts Institute of Technology, USA, James KoppelMassachusetts Institute of Technology, USA, Armando Solar-LezamaMassachusetts Institute of Technology, USA | ||