Another update from ingydotnet^djgoku

Task/S-Expressions/JavaScript/s-expressions.js

@@ -0,0 +1,38 @@
+String.prototype.parseSexpr = function() {
+	var t = this.match(/\s*("[^"]*"|\(|\)|"|[^\s()"]+)/g)
+	for (var o, c=0, i=t.length-1; i>=0; i--) {
+		var n, ti = t[i].trim()
+		if (ti == '"') return
+		else if (ti == '(') t[i]='[', c+=1
+		else if (ti == ')') t[i]=']', c-=1
+		else if ((n=+ti) == ti) t[i]=n
+		else t[i] = '\'' + ti.replace('\'', '\\\'') + '\''
+		if (i>0 && ti!=']' && t[i-1].trim()!='(' ) t.splice(i,0, ',')
+		if (!c) if (!o) o=true; else return
+	}
+	return c ? undefined : eval(t.join(''))
+}
+
+Array.prototype.toString = function() {
+	var s=''; for (var i=0, e=this.length; i<e; i++) s+=(s?' ':'')+this[i]
+	return '('+s+')'
+}
+
+Array.prototype.toPretty = function(s) {
+	if (!s) s = ''
+	var r = s + '(<br>'
+	var s2 = s + Array(6).join('&nbsp;')
+	for (var i=0, e=this.length; i<e; i+=1) {
+		var ai = this[i]
+		r += ai.constructor != Array ? s2+ai+'<br>' : ai.toPretty(s2)
+	}
+	return r + s + ')<br>'
+}
+
+var str = '((data "quoted data" 123 4.5)\n (data (!@# (4.5) "(more" "data)")))'
+document.write('text:<br>', str.replace(/\n/g,'<br>').replace(/ /g,'&nbsp;'), '<br><br>')
+var sexpr = str.parseSexpr()
+if (sexpr === undefined)
+	document.write('Invalid s-expr!', '<br>')
+else
+	document.write('s-expr:<br>', sexpr, '<br><br>', sexpr.constructor != Array ? '' : 'pretty print:<br>' + sexpr.toPretty())