add handy re-indenting script

diff --git a/reindent.py b/reindent.py
new file mode 100755 (executable)
index 0000000..85a426a
--- /dev/null
+++ b/reindent.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python3
+""" handy script for re-indenting text to be in multiples of `    `"""
+import sys
+
+indent_unit = "    "
+
+
+def ind_print(v):
+    print(indent_unit * (len(indent_stack) - 1) + v)
+
+
+with open(sys.argv[1]) as f:
+    indent_stack = [""]
+    for line in f:
+        line = line.rstrip().expandtabs()
+        indent = line[:-len(line.lstrip())]
+        unindented = line[len(indent):]
+        if unindented == '':
+            print()
+            continue
+        while len(indent_stack[-1]) > len(indent):
+            indent_stack.pop()
+            assert len(indent_stack[-1]) >= len(indent), \
+                "popped intermediate indentation"
+        if len(indent_stack[-1]) < len(indent):
+            indent_stack.append(indent)
+        ind_print(unindented)