====== EBNF Parser & Syntax Diagram Renderer ======
The //EBNF Parser & Syntax Diagram Renderer// can be used stand-alone or as Dokuwiki-Plugin.

===== Download and Install=====
  * https://www.dokuwiki.org/plugin:ebnf
  * Requirements: Make sure to have the [[http://www.php.net/manual/en/image.requirements.php|GD library]] ready :!:
===== How to use =====

  <ebnf> "EBNF defined in itself" {
  syntax     = [ title ] "{" { production } "}" [ comment ].
  production = identifier "=" expression ( "." | ";" ) .
  expression = term { "|" term } .
  term       = factor { factor } .
  factor     = identifier
             | literal
             | "[" expression "]"
             | "(" expression ")"
             | "{" expression "}" .
  identifier = character { character } .
  title      = literal .
  comment    = literal .
  literal    = "'" character { character } "'"
             | '"' character { character } '"' .
  }</ebnf>


<ebnf> "EBNF defined in itself" {
  syntax     = [ title ] "{" { production } "}" [ comment ].
  production = identifier "=" expression ( "." | ";" ) .
  expression = term { "|" term } .
  term       = factor { factor } .
  factor     = identifier
             | literal
             | "[" expression "]"
             | "(" expression ")"
             | "{" expression "}" .
  identifier = character { character } .
  title      = literal .
  comment    = literal .
  literal    = "'" character { character } "'"
             | '"' character { character } '"' .
} </ebnf>

The script is also available as stand-alone version under: ''your_dokuwiki/lib/plugins/ebnf/ebnf.php''
  .../ebnf.php?syntax="EBNF"{ hello = "Hello World". }"Some additional Comments"
Note: The stand-alone script supports also XML output
  .../ebnf.php?syntax={ hello = "EBNF Hello World in XML". }&format=xml

===== Syntax =====
  * See examples: [[examples]]
  * [[wp>EBNF]]
  * [[wp>Wirth_syntax_notation]]

===== Todo & Ideas =====
  * Ellipse ... for enumerations. E.g. ''digits'': 
    * temp hack in v0.2: ''function render_node($node, $lefttoright)''<code php> ...
    else {
      if ($text!="...")
	      rr($im, UNIT, 0, $w-UNIT-1, $h-1, UNIT/2, $black);
      imagestring($im, FONT, 2*UNIT, ($h-imagefontheight(FONT))/2, 
        $text, $text!="..."?$blue:$black);
    } ...</code>
  * Other fonts
  * Configurable dimensions
  * escape-chars and or unicode in terminals
  * Adding //Regexp// beside terminal and identifiers
  * using a lightweight syntaxtree instead DOM
  * using some standard parsing mechanism
  * support for comments & special-sequences ''? ... ?''
  * http://www.cs.man.ac.uk/~pjj/bnf/ebnf.html
  * replace antialias function