Closure compiler: add pydoc for parts of third_party/closure_compiler/.

third_party/closure_compiler/processor.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+"""Process Chrome resources (HTML/CSS/JS) to handle <include> and <if> tags."""
+
 from collections import defaultdict
 import re
 import os
 
 
 class LineNumber(object):
-  def __init__(self, file, line_number):
-    self.file = file
+  """A simple wrapper to hold line information (e.g. file.js:32).
+  
+  Args:
+    source_file: A file path.
+    line_number: The line in |file|.
+  """
+  def __init__(self, source_file, line_number):
+    self.file = source_file
     self.line_number = int(line_number)
 
 
 class FileCache(object):
+  """An in-memory cache to speed up reading the same files over and over.
+  
+  Usage:
+      FileCache.read(path_to_file)
+  """
+
   _cache = defaultdict(str)
 
-  def _read(self, file):
-    file = os.path.abspath(file)
-    self._cache[file] = self._cache[file] or open(file, "r").read()
-    return self._cache[file]
+  @classmethod
+  def read(self, source_file):
+    """Read a file and return it as a string.
 
-  @staticmethod
-  def read(file):
-    return FileCache()._read(file)
+    Args:
+        source_file: a file to read and return the contents of.
+
+    Returns:
+        |file| as a string.
+    """
+    abs_file = os.path.abspath(source_file)
+    self._cache[abs_file] = self._cache[abs_file] or open(abs_file, "r").read()
+    return self._cache[abs_file]
 
 
 class Processor(object):
+  """Processes resource files, inlining the contents of <include> tags, removing
+  <if> tags, and retaining original line info.
+
+  For example
+
+      1: /* blah.js */
+      2: <if expr="is_win">
+      3: <include src="win.js">
+      4: </if>
+
+  would be turned into:
+
+      1: /* blah.js */
+      2:
+      3: /* win.js */
+      4: alert('Ew; Windows.');
+      5:
+
+  Args:
+      source_file: A file to process.
+
+  Attributes:
+      contents: Expanded contents after inlining <include>s and stripping <if>s.
+      included_files: A list of files that were inlined via <include>.
+  """
+
   _IF_TAGS_REG = "</?if[^>]*?>"
   _INCLUDE_REG = "<include[^>]+src=['\"]([^>]*)['\"]>"
 
-  def __init__(self, file):
+  def __init__(self, source_file):
     self._included_files = set()
     self._index = 0
-    self._lines = self._get_file(file)
+    self._lines = self._get_file(source_file)
 
     while self._index < len(self._lines):
       current_line = self._lines[self._index]
       match = re.search(self._INCLUDE_REG, current_line[2])
       if match:
         file_dir = os.path.dirname(current_line[0])
         self._include_file(os.path.join(file_dir, match.group(1)))
       else:
         self._index += 1
 
     for i, line in enumerate(self._lines):
       self._lines[i] = line[:2] + (re.sub(self._IF_TAGS_REG, "", line[2]),)
 
     self.contents = "\n".join(l[2] for l in self._lines)
 
   # Returns a list of tuples in the format: (file, line number, line contents).
-  def _get_file(self, file):
-    lines = FileCache.read(file).splitlines()
-    return [(file, lnum + 1, line) for lnum, line in enumerate(lines)]
+  def _get_file(self, source_file):
+    lines = FileCache.read(source_file).splitlines()
+    return [(source_file, lnum + 1, line) for lnum, line in enumerate(lines)]
 
-  def _include_file(self, file):
-    self._included_files.add(file)
-    f = self._get_file(file)
+  def _include_file(self, source_file):
+    self._included_files.add(source_file)
+    f = self._get_file(source_file)
     self._lines = self._lines[:self._index] + f + self._lines[self._index + 1:]
 
   def get_file_from_line(self, line_number):
+    """Get the original file and line number for an expanded file's line number.
+
+    Args:
+        line_number: A processed file's line number.
+    """
     line_number = int(line_number) - 1
     return LineNumber(self._lines[line_number][0], self._lines[line_number][1])
 
+  @property
   def included_files(self):
+    """A list of files that were inlined via <include>."""
     return self._included_files