closed-social
/
gitea

<!doctype html><html>  <head>    <title>CodeMirror: EBNF Mode</title>    <meta charset="utf-8"/>    <link rel=stylesheet href="../../doc/docs.css">
    <link rel="stylesheet" href="../../lib/codemirror.css">    <script src="../../lib/codemirror.js"></script>    <script src="../javascript/javascript.js"></script>    <script src="ebnf.js"></script>    <style type="text/css">.CodeMirror {border-top: 1px solid black; border-bottom: 1px solid black;}</style>  </head>  <body>    <div id=nav>      <a href="http://codemirror.net"><h1>CodeMirror</h1><img id=logo src="../../doc/logo.png"></a>
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    <article>      <h2>EBNF Mode (bracesMode setting = "javascript")</h2>      <form><textarea id="code" name="code">/* description: Parses end executes mathematical expressions. */
/* lexical grammar */%lex
%%\s+                   /* skip whitespace */[0-9]+("."[0-9]+)?\b  return 'NUMBER';"*"                   return '*';"/"                   return '/';"-"                   return '-';"+"                   return '+';"^"                   return '^';"("                   return '(';")"                   return ')';"PI"                  return 'PI';"E"                   return 'E';&lt;&lt;EOF&gt;&gt;               return 'EOF';
/lex
/* operator associations and precedence */
%left '+' '-'%left '*' '/'%left '^'%left UMINUS
%start expressions
%% /* language grammar */
expressions: e EOF{print($1); return $1;};
e: e '+' e{$$ = $1+$3;}| e '-' e{$$ = $1-$3;}| e '*' e{$$ = $1*$3;}| e '/' e{$$ = $1/$3;}| e '^' e{$$ = Math.pow($1, $3);}| '-' e %prec UMINUS{$$ = -$2;}| '(' e ')'{$$ = $2;}| NUMBER{$$ = Number(yytext);}| E{$$ = Math.E;}| PI{$$ = Math.PI;};</textarea></form>      <script>        var editor = CodeMirror.fromTextArea(document.getElementById("code"), {          mode: {name: "ebnf"},          lineNumbers: true,          bracesMode: 'javascript'        });      </script>      <h3>The EBNF Mode</h3>      <p> Created by <a href="https://github.com/robertleeplummerjr">Robert Plummer</a></p>    </article>  </body></html>