ghc-happy-lib

Happy is a parser generator for Haskell implemented using this library

Happy is a parser generator for Haskell. Given a grammar specification in BNF, Happy generates Haskell code to parse the grammar. Happy works in a similar way to the 'yacc' tool for C. This library provides the following functionality: * Data type definitions for the Grammar AST type, capturing the information in .y-files (Happy.Grammar) * A parser for happy grammar files (.y) to produce a Grammar (Happy.Frontend.*) * Implementations of the text book algorithms that compute the LR action and goto tables for the given 'Grammar' (Happy.Tabular.*) * An LALR code generator to produce table-driven, deterministic parsing code in Haskell (Happy.Backend.LALR.*) * A (less maintained) GLR code generator to produce table-driven, non-deterministic parsing code in Haskell, where ambiguous parses produce multiple parse trees (Happy.Backend.GLR.*).