--- a/python/ppci/c3/lexer.py	Fri Dec 06 12:45:02 2013 +0100
+++ b/python/ppci/c3/lexer.py	Fri Dec 06 13:50:38 2013 +0100
@@ -8,13 +8,14 @@
 """
 
 keywords = ['and', 'or', 'not', 'true', 'false',
-        'else', 'if', 'while', 'return',
-        'function', 'var', 'type', 'const',
-        'struct', 'cast',
-        'import', 'module']
+            'else', 'if', 'while', 'return',
+            'function', 'var', 'type', 'const',
+            'struct', 'cast',
+            'import', 'module']
 
 
 class Lexer:
+    """ Generates a sequence of token from an input stream """
     def __init__(self, diag):
         self.diag = diag
 
@@ -65,7 +66,7 @@
             elif typ == 'SKIP':
                 pass
             elif incomment:
-                pass # Wait until we are not in a comment section
+                pass    # Wait until we are not in a comment section
             else:
                 if typ == 'ID':
                     if val in keywords:
@@ -82,7 +83,7 @@
                 elif typ == 'STRING':
                     val = val[1:-1]
                 loc = SourceLocation(filename, line, mo.start() - line_start,
-                        mo.end() - mo.start())
+                                     mo.end() - mo.start())
                 yield Token(typ, val, loc)
             pos = mo.end()
             mo = gettok(s, pos)