/parserlib

A c++17 recursive-descent generic parsing library that supports left recursion, tokenization, AST tree creation, multiple error handling etc..

Primary LanguageC++Apache License 2.0Apache-2.0

Parserlib

A c++17 recursive-descent parser library that:

  • provides an easy EBNF-like syntax for writing grammars.
  • allows any type of STL-like container or STL-like stream to be used as input.
  • allows case-insensitive parsing.
  • allows for multiple errors per parse (error recovery).
  • allows for parsing left-recursive grammars.

Version 1.0.0.7.

Table Of Contents

Versions

  • 1.0.0.7

    • Rewritten from scratch, to improve quality of the API.

  • 1.0.0.6

    • Added function-based parsing.

  • 1.0.0.5

    • Added custom match functions in order to allow the resolution of ambiguities while parsing.
    • allowed terminal values to be of different type that the value of the source container, in order to allow the result of a parse (the ast nodes created by a parse) to be fed to another parse function.
    • added terminal parsing via functions.
    • added parsing via standalone functions.
    • added multiple error handling.

  • 1.0.0.4

    • Rewrote the library:
      • all parser grammar classes are now inside a single template class class parser_engine<SourceT, MatchIdT>, for the following reasons:
        • compiler performance (MSVC 32-bit regularly crashed with out of memory error from the many template instantiations of previous versions).
        • library code organization; writing a grammar usually requires including all the grammar constructs, so it is reduntant to have separate files for each grammar-related class.
        • user code organization; whole grammars need to be specialized on source type.
      • coding style is closer to the standard: all identifiers are lower case, words are separated by underscores, idiomatic c++ is used whenever possible.
    • Rewrote the documentation, due to more functionality to be added in the future.

  • 1.0.0.3

    • Reorganized the library in order to support compiler front ends into a separate namespace. The main library is now in namespace parserlib::core.
    • Added namespace parserlib::cfe which now contains the compiler-front-end functionality.
    • separated tokenization and parsing phases for compiler-front-ends.
    • Added relevant documentation and unit tests.

  • 1.0.0.2

    • Rewrote the library from scratch in order to provide a better interface. Changes:

      • All the getter methods now start with 'get', in order to play better with Intellisense.
      • The ParseContext class is now configured over the Source type, with the default class being the class SourceString.
      • The class SourceString provides custom iterator which counts lines and columns, compatible with the std::string interface.
      • The functions terminal, terminalSet, terminalRange are changed to term, oneOf, oneIn.
      • Matches are now only hierarchical (as in operator >= of previous version).
      • The 'operator >= has been replaced with operator ->*, which is much more distinct than the former; no more typing accidentally '>>' where >= was intended.
      • The default match id type is no longer a string; it is an int.
      • Simplified the left recursion parsing implementation.

  • 1.0.0.1

    • Added support for compiler front-end construction.

  • 1.0.0.0

    • Initial release.

TODO

TODO list in the current version:

  • document code.
  • complete the library documentation.
  • provide API for counting lines and columns for character parsers.
  • provide translation of matches to AST nodes.