complete redesign: use nodejs on server instead of php - documentation to be updated

nodejs/node_modules/stylus/lib/functions/substr.js

@@ -0,0 +1,22 @@
+var utils = require('../utils')
+  , nodes = require('../nodes');
+
+/**
+ * Returns substring of the given `val`.
+ *
+ * @param {String|Ident} val
+ * @param {Number} start
+ * @param {Number} [length]
+ * @return {String|Ident}
+ * @api public
+ */
+
+module.exports = function substr(val, start, length){
+  utils.assertString(val, 'val');
+  utils.assertType(start, 'unit', 'start');
+  length = length && length.val;
+  var res = val.string.substr(start.val, length);
+  return val instanceof nodes.Ident
+      ? new nodes.Ident(res)
+      : new nodes.String(res);
+};