Add FileFilter convenience class to llnl.util.filesystem.

lib/spack/llnl/util/filesystem.py

@@ -25,7 +25,7 @@
 __all__ = ['set_install_permissions', 'install', 'install_tree', 'traverse_tree',
            'expand_user', 'working_dir', 'touch', 'touchp', 'mkdirp',
            'force_remove', 'join_path', 'ancestor', 'can_access', 'filter_file',
-           'change_sed_delimiter', 'is_exe', 'force_symlink']
+           'FileFilter', 'change_sed_delimiter', 'is_exe', 'force_symlink']
 
 import os
 import sys
@@ -96,6 +96,15 @@ def groupid_to_group(x):
                 shutil.rmtree(backup, ignore_errors=True)
 
 
+class FileFilter(object):
+    """Convenience class for calling filter_file a lot."""
+    def __init__(self, *filenames):
+        self.filenames = filenames
+
+    def filter(self, regex, repl, **kwargs):
+        return filter_file(regex, repl, *self.filenames, **kwargs)
+
+
 def change_sed_delimiter(old_delim, new_delim, *filenames):
     """Find all sed search/replace commands and change the delimiter.
        e.g., if the file contains seds that look like 's///', you can