Section: New Results

General Parser Combinators

Parser combinators are a well-known approach to parsing where grammars are represented using (higher-order) functions. Unfortunately, parser combinators are commonly implemented using recursive descent parsing as the underlying algorithm. As a result, most parser combinators frameworks do not support left-recursive rules, and may exhibit exponential runtime performance due to backtracking. Anastasia Izmaylova and Ali Afroozeh developed “general parser combinators” (GPC) which do not suffer from these problems: all context-free grammars are supported (even ambiguous ones) and performance is worst-case cubic. As result, GPC combines the expressiveness and performance guarantees of general parsing algorithms like GLL and GLR with the flexibility and extensibility of parser combinators.