<!doctype html>
<title>CodeMirror: Scheme 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="scheme.js"></script>
<style>.CodeMirror {background: #f8f8f8;}</style>
<div id=nav>
<a href="http://codemirror.net"><h1>CodeMirror</h1><img id=logo src="../../doc/logo.png"></a>
<ul>
<li><a href="../../index.html">Home</a>
<li><a href="../../doc/manual.html">Manual</a>
<li><a href="https://github.com/codemirror/codemirror">Code</a>
</ul>
<ul>
<li><a href="../index.html">Language modes</a>
<li><a class=active href="#">Scheme</a>
</ul>
</div>
<article>
<h2>Scheme mode</h2>
<form><textarea id="code" name="code">
; See if the input starts with a given symbol.
(define (match-symbol input pattern)
(cond ((null? (remain input)) #f)
((eqv? (car (remain input)) pattern) (r-cdr input))
(else #f)))
; Allow the input to start with one of a list of patterns.
(define (match-or input pattern)
(cond ((null? pattern) #f)
((match-pattern input (car pattern)))
(else (match-or input (cdr pattern)))))
; Allow a sequence of patterns.
(define (match-seq input pattern)
(if (null? pattern)
input
(let ((match (match-pattern input (car pattern))))
(if match (match-seq match (cdr pattern)) #f))))
; Match with the pattern but no problem if it does not match.
(define (match-opt input pattern)
(let ((match (match-pattern input (car pattern))))
(if match match input)))
; Match anything (other than '()), until pattern is found. The rather
; clumsy form of requiring an ending pattern is needed to decide where
; the end of the match is. If none is given, this will match the rest
; of the sentence.
(define (match-any input pattern)
(cond ((null? (remain input)) #f)
((null? pattern) (f-cons (remain input) (clear-remain input)))
(else
(let ((accum-any (collector)))
(define (match-pattern-any input pattern)
(cond ((null? (remain input)) #f)
(else (accum-any (car (remain input)))
(cond ((match-pattern (r-cdr input) pattern))
(else (match-pattern-any (r-cdr input) pattern))))))
(let ((retval (match-pattern-any input (car pattern))))
(if retval
(f-cons (accum-any) retval)
#f))))))
</textarea></form>
<script>
var editor = CodeMirror.fromTextArea(document.getElementById("code"), {});
</script>
<p><strong>MIME types defined:</strong> <code>text/x-scheme</code>.</p>
</article>