Wed 21 Jun 2023 17:40 - 18:00 at Cypress 2 - PLDI: Parsing & Formal Languages Chair(s): Eric Eide

Lexers and parsers are typically defined separately and connected by a token stream. This separate definition is important for modularity and reduces the potential for parsing ambiguity. However, materializing tokens as data structures and case-switching on tokens comes with a cost.

We show how to fuse separately-defined lexers and parsers, drastically improving performance without compromising modularity or increasing ambiguity. We propose a deterministic variant of Greibach Normal Form that ensures deterministic parsing with a single token of lookahead and makes fusion strikingly simple, and prove that normalizing context free expressions into the deterministic normal form is semantics-preserving. Our staged parser combinator library, flap, provides a standard interface, but generates specialized token-free code that runs two to six times faster than ocamlyacc on a range of benchmarks.

Wed 21 Jun

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16:00 - 18:00
PLDI: Parsing & Formal LanguagesPLDI Research Papers at Cypress 2
Chair(s): Eric Eide University of Utah

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16:00
20m
Talk
Search-Based Regular Expression Inference on a GPU
PLDI Research Papers
Mojtaba Valizadeh University of Sussex, Martin Berger
DOI Pre-print
16:20
20m
Talk
Derivative Based Nonbacktracking Real-World Regex Matching with Backtracking Semantics
PLDI Research Papers
Dan Moseley Microsoft DevDiv, Mario Nishio Microsoft Azure, Jose Perez Rodriguez Microsoft DevDiv, Olli Saarikivi Microsoft Research, Redmond, Stephen Toub Microsoft DevDiv, Margus Veanes Microsoft, Tiki Wan Microsoft Azure, Eric Xu Microsoft, USA
DOI
16:40
20m
Talk
Repairing Regular Expressions for Extraction
PLDI Research Papers
Nariyoshi Chida NTT Social Informatics Laboratories, Tachio Terauchi Waseda University
DOI
17:00
20m
Talk
Recursive State Machine Guided Graph Folding for Context-Free Language Reachability
PLDI Research Papers
Yuxiang Lei University of New South Wales, Yulei Sui University of New South Wales, Sydney, Shin Hwei Tan Concordia University, Qirun Zhang Georgia Institute of Technology
DOI
17:20
20m
Talk
Interval Parsing Grammars for File Format Parsing
PLDI Research Papers
Jialun Zhang Pennsylvania State University, Greg Morrisett Cornell University, Gang Tan Pennsylvania State University
DOI
17:40
20m
Talk
flap: A Deterministic Parser with Fused Lexing
PLDI Research Papers
Jeremy Yallop University of Cambridge, Ningning Xie Google DeepMind / University of Toronto, Neel Krishnaswami University of Cambridge
DOI Pre-print