EBNFParser 2.1

very powerful and optional parser framework for python

EBNFParser

Parse Many, Any, Every

HomePage

• Python Project(Support Python 3.6+) (v 2.0)

  • Old Version : Misakawa(v0.x)

  • Old Version : Ruikowa(v1.x)

P.S: Everything except THIS README is out of date, you can refer here for more information..

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Install

• Python

  • pip

  pip installl -U EBNFParser

  • setup

    git clone https://github.com/thautwarm/EBNFParser
    cd EBNFParser/Python
    python setup.py install

An Introduce to EBNFParser

EBNFParser seems to be a parser framework for parsing EBNF syntaxes, however, the syntax of EBNF here is not the same as that standard one.

The name of current EBNFParser’s version is Ruikowa, so you can call this idiom as Ruikowa for convenience’ sake.

Here is an example for you to get a knowledge of Ruikowa for parsing Java switch syntax.

deftoken Token.Java # use the token definition at source file `./Token/Java`.

ignore [Space] # ignore tokens like Space;

Space    := R'\s+'; # define tokenizer(s) with specific name `Space`

switch   ::= 'switch' '(' expression ')' newline*
             '{'
                case*
                [default]
             '}' ;

case     ::= 'case' ':' body    ;

default  ::= 'default' ':' body ;

body     ::= block | statement  ;

block    ::= '{' statement* '}' ;

...

Now I’m going to tell you how to use EBNFParser to write a parser for Lisp quickly.

• Install

  pip install -U EBNFParser

• Write a file and name it as lispGrammar with following content.

  ignore [N]
  
  N := R'\n', R'\t', ' ';
  
  Atom    := R'[^\(\)\s\`]?'; # use Regex
  Expr  ::= Atom
          | Quote
          | '(' Expr* ')';
  
  Quote ::=  '`' Expr ;
  Stmt  ::= Expr*;

• Generate your parser and tokenizer.

  ruiko ./lispGrammar ./lispParser.py

• Test your parser.

  python testLang.py Stmt "(+ 1 2)" -o test.ast
  Stmt[
      Expr[
          "("
          Expr[
              "+"
          ]
          Expr[
              "1"
          ]
          Expr[
              "2"
          ]
          ")"
      ]
  ]

  Moreover, here is a result in JSON format at test.json.

Usage

• Command Line Tools

  • ruiko.

  ruiko ./<grammar File> ./<output Python File(endswith ".py")>
          [--testTk] # print tokenized words or not

  Use command ruiko to generate parser and token files, and then you can use testLang.py to test your parser.

  python ./test_lang.py Stmt " (+ 1 2) " -o test.json --testTk

• Use EBNFParser in your own project.

Here are some examples to refer:

EBNFParser 2.0

• Rem The Rem programming language.

Before EBNFParser 1.1.

• DBG-Lang

  A DSL for SQL development in Python areas.
• Rem(Based EBNFParser1.1)

  A full featured modern language to enhance program readability based on CPython.
• Lang.Red

  An attempt to making ASDL in CPython(unfinished yet)

Source

• Source of Ruikowa

• Core : Node.py

• Bootstrap Compiler

Will support C# and Rem.

License

MIT