limit arguments to not support duplicate names

test.py

@@ -0,0 +1,35 @@
+import string
+from itertools import product
+import sys
+
+def generate_names(max_width, skip_keywords=None):
+    if skip_keywords is None:
+        skip_keywords = {"if", "else", "while", "forever", "for", "break", "continue",
+                         "return", "let", "import", "from", "do", "true", "false", "null",
+                         "delete", "not", "try", "catch", "in"}
+    else:
+        skip_keywords = set(skip_keywords)
+
+    chars = string.ascii_lowercase
+    first = True
+    write = sys.stdout.write
+
+    for length in range(1, max_width + 1):
+        print(length, file=sys.stderr)
+        i = 0
+        for p in product(chars, repeat=length):
+            name = ''.join(p)
+            if name in skip_keywords:
+                continue
+            if not first:
+                write('\n')
+            write(name)
+            first = False
+            if i>10000000:
+                break
+            i+=1
+
+# Example usage:
+max_width = 15
+# sys.stdout.write("let ")
+generate_names(max_width)