1 files changed, 43 insertions, 0 deletions
diff --git a/node_modules/safe-regex/index.js b/node_modules/safe-regex/index.js
new file mode 100644
index 0000000..488f501
--- /dev/null
+++ b/node_modules/safe-regex/index.js
@@ -0,0 +1,43 @@
+var parse = require('ret');
+var types = parse.types;
+
+module.exports = function (re, opts) {
+    if (!opts) opts = {};
+    var replimit = opts.limit === undefined ? 25 : opts.limit;
+    
+    if (isRegExp(re)) re = re.source;
+    else if (typeof re !== 'string') re = String(re);
+    
+    try { re = parse(re) }
+    catch (err) { return false }
+    
+    var reps = 0;
+    return (function walk (node, starHeight) {
+        if (node.type === types.REPETITION) {
+            starHeight ++;
+            reps ++;
+            if (starHeight > 1) return false;
+            if (reps > replimit) return false;
+        }
+        
+        if (node.options) {
+            for (var i = 0, len = node.options.length; i < len; i++) {
+                var ok = walk({ stack: node.options[i] }, starHeight);
+                if (!ok) return false;
+            }
+        }
+        var stack = node.stack || (node.value && node.value.stack);
+        if (!stack) return true;
+        
+        for (var i = 0; i < stack.length; i++) {
+            var ok = walk(stack[i], starHeight);
+            if (!ok) return false;
+        }
+        
+        return true;
+    })(re, 0);
+};
+
+function isRegExp (x) {
+    return {}.toString.call(x) === '[object RegExp]';
+}