Cheetah/Utils/Indenter.py

   1 #!/usr/bin/env python
   2 # $Id: Indenter.py,v 1.7 2006/01/08 01:09:30 tavis_rudd Exp $
   3 """Indentation maker.
   4 @@TR: this code is unsupported and largely undocumented ...
   5
   6 This version is based directly on code by Robert Kuzelj
   7 <robert_kuzelj@yahoo.com> and uses his directive syntax.  Some classes and
   8 attributes have been renamed.  Indentation is output via
   9 $self._CHEETAH__indenter.indent() to prevent '_indenter' being looked up on the
  10 searchList and another one being found.  The directive syntax will
  11 soon be changed somewhat.
  12
  13 Meta-Data
  14 ================================================================================
  15 Author: Mike Orr <iron@mso.oz.net>
  16 License: This software is released for unlimited distribution under the
  17          terms of the MIT license.  See the LICENSE file.
  18 Version: $Revision: 1.7 $
  19 Start Date: 2001/11/07
  20 Last Revision Date: $Date: 2006/01/08 01:09:30 $
  21 """
  22 __author__ = "Mike Orr <iron@mso.oz.net>"
  23 __revision__ = "$Revision: 1.7 $"[11:-2]
  24
  25 import re
  26 import sys
  27
  28 def indentize(source):
  29     return IndentProcessor().process(source)
  30
  31 class IndentProcessor:
  32     """Preprocess #indent tags."""
  33     LINE_SEP = '\n'
  34     ARGS = "args"
  35     INDENT_DIR = re.compile(r'[ \t]*#indent[ \t]*(?P<args>.*)')
  36     DIRECTIVE = re.compile(r"[ \t]*#")
  37     WS = "ws"
  38     WHITESPACES = re.compile(r"(?P<ws>[ \t]*)")
  39
  40     INC = "++"
  41     DEC = "--"
  42
  43     SET = "="
  44     CHAR = "char"
  45
  46     ON = "on"
  47     OFF = "off"
  48
  49     PUSH = "push"
  50     POP = "pop"
  51
  52     def process(self, _txt):
  53         result = []
  54
  55         for line in _txt.splitlines():
  56             match = self.INDENT_DIR.match(line)
  57             if match:
  58                 #is indention directive
  59                 args = match.group(self.ARGS).strip()
  60                 if args == self.ON:
  61                     line = "#silent $self._CHEETAH__indenter.on()"
  62                 elif args == self.OFF:
  63                     line = "#silent $self._CHEETAH__indenter.off()"
  64                 elif args == self.INC:
  65                     line = "#silent $self._CHEETAH__indenter.inc()"
  66                 elif args == self.DEC:
  67                     line = "#silent $self._CHEETAH__indenter.dec()"
  68                 elif args.startswith(self.SET):
  69                     level = int(args[1:])
  70                     line = "#silent $self._CHEETAH__indenter.setLevel(%(level)d)" % {"level":level}
  71                 elif args.startswith('chars'):
  72                     self.indentChars = eval(args.split('=')[1])
  73                     line = "#silent $self._CHEETAH__indenter.setChars(%(level)d)" % {"level":level}
  74                 elif args.startswith(self.PUSH):
  75                     line = "#silent $self._CHEETAH__indenter.push()"
  76                 elif args.startswith(self.POP):
  77                     line = "#silent $self._CHEETAH__indenter.pop()"
  78             else:
  79                 match = self.DIRECTIVE.match(line)
  80                 if not match:
  81                     #is not another directive
  82                     match = self.WHITESPACES.match(line)
  83                     if match:
  84                         size = len(match.group("ws").expandtabs(4))
  85                         line = ("${self._CHEETAH__indenter.indent(%(size)d)}" % {"size":size}) + line.lstrip()
  86                     else:
  87                         line = "${self._CHEETAH__indenter.indent(0)}" + line
  88             result.append(line)
  89
  90         return self.LINE_SEP.join(result)
  91
  92 class Indenter:
  93     """A class that keeps track of the current indentation level.
  94     .indent() returns the appropriate amount of indentation.
  95     """
  96     def __init__(self):
  97         self.On = 1
  98         self.Level = 0
  99         self.Chars = " "*4
 100         self.LevelStack = []
 101     def on(self):
 102         self.On = 1
 103     def off(self):
 104         self.On = 0
 105     def inc(self):
 106         self.Level += 1
 107     def dec(self):
 108         """decrement can only be applied to values greater zero
 109             values below zero don't make any sense at all!"""
 110         if self.Level > 0:
 111             self.Level -= 1
 112     def push(self):
 113         self.LevelStack.append(self.Level)
 114     def pop(self):
 115         """the levestack can not become -1. any attempt to do so
 116            sets the level to 0!"""
 117         if len(self.LevelStack) > 0:
 118             self.Level = self.LevelStack.pop()
 119         else:
 120             self.Level = 0
 121     def setLevel(self, _level):
 122         """the leve can't be less than zero. any attempt to do so
 123            sets the level automatically to zero!"""
 124         if _level < 0:
 125             self.Level = 0
 126         else:
 127             self.Level = _level
 128     def setChar(self, _chars):
 129         self.Chars = _chars
 130     def indent(self, _default=0):
 131         if self.On:
 132             return self.Chars * self.Level
 133         else:
 134             return " " * _default
 135