error: add a new UnknownIdentifier error type

This will be used by the revset and fileset code to communicate more
specific errors to higher levels so that we might be able to offer
suggestions about what function might have been similar.

mercurial/error.py

@@ -1,157 +1,166 b''
 # error.py - Mercurial exceptions
 #
 # Copyright 2005-2008 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """Mercurial exceptions.
 
 This allows us to catch exceptions at higher levels without forcing
 imports.
 """
 
 # Do not import anything here, please
 
 class RevlogError(Exception):
     pass
 
 class FilteredIndexError(IndexError):
     pass
 
 class LookupError(RevlogError, KeyError):
     def __init__(self, name, index, message):
         self.name = name
         self.index = index
         # this can't be called 'message' because at least some installs of
         # Python 2.6+ complain about the 'message' property being deprecated
         self.lookupmessage = message
         if isinstance(name, str) and len(name) == 20:
             from node import short
             name = short(name)
         RevlogError.__init__(self, '%s@%s: %s' % (index, name, message))
 
     def __str__(self):
         return RevlogError.__str__(self)
 
 class FilteredLookupError(LookupError):
     pass
 
 class ManifestLookupError(LookupError):
     pass
 
 class CommandError(Exception):
     """Exception raised on errors in parsing the command line."""
 
 class InterventionRequired(Exception):
     """Exception raised when a command requires human intervention."""
 
 class Abort(Exception):
     """Raised if a command needs to print an error and exit."""
     def __init__(self, *args, **kw):
         Exception.__init__(self, *args)
         self.hint = kw.get('hint')
 
 class HookAbort(Abort):
     """raised when a validation hook fails, aborting an operation
 
     Exists to allow more specialized catching."""
     pass
 
 class ConfigError(Abort):
     """Exception raised when parsing config files"""
 
 class OutOfBandError(Exception):
     """Exception raised when a remote repo reports failure"""
 
 class ParseError(Exception):
     """Raised when parsing config files and {rev,file}sets (msg[, pos])"""
 
+class UnknownIdentifier(ParseError):
+    """Exception raised when a {rev,file}set references an unknown identifier"""
+
+    def __init__(self, function, symbols):
+        from i18n import _
+        ParseError.__init__(self, _("unknown identifier: %s") % function)
+        self.function = function
+        self.symbols = symbols
+
 class RepoError(Exception):
     def __init__(self, *args, **kw):
         Exception.__init__(self, *args)
         self.hint = kw.get('hint')
 
 class RepoLookupError(RepoError):
     pass
 
 class FilteredRepoLookupError(RepoLookupError):
     pass
 
 class CapabilityError(RepoError):
     pass
 
 class RequirementError(RepoError):
     """Exception raised if .hg/requires has an unknown entry."""
     pass
 
 class LockError(IOError):
     def __init__(self, errno, strerror, filename, desc):
         IOError.__init__(self, errno, strerror, filename)
         self.desc = desc
 
 class LockHeld(LockError):
     def __init__(self, errno, filename, desc, locker):
         LockError.__init__(self, errno, 'Lock held', filename, desc)
         self.locker = locker
 
 class LockUnavailable(LockError):
     pass
 
 class ResponseError(Exception):
     """Raised to print an error with part of output and exit."""
 
 class UnknownCommand(Exception):
     """Exception raised if command is not in the command table."""
 
 class AmbiguousCommand(Exception):
     """Exception raised if command shortcut matches more than one command."""
 
 # derived from KeyboardInterrupt to simplify some breakout code
 class SignalInterrupt(KeyboardInterrupt):
     """Exception raised on SIGTERM and SIGHUP."""
 
 class SignatureError(Exception):
     pass
 
 class PushRaced(RuntimeError):
     """An exception raised during unbundling that indicate a push race"""
 
 # bundle2 related errors
 class BundleValueError(ValueError):
     """error raised when bundle2 cannot be processed"""
 
 class UnsupportedPartError(BundleValueError):
     def __init__(self, parttype=None, params=()):
         self.parttype = parttype
         self.params = params
         if self.parttype is None:
             msg = 'Stream Parameter'
         else:
             msg = parttype
         if self.params:
             msg = '%s - %s' % (msg, ', '.join(self.params))
         ValueError.__init__(self, msg)
 
 class ReadOnlyPartError(RuntimeError):
     """error raised when code tries to alter a part being generated"""
     pass
 
 class CensoredNodeError(RevlogError):
     """error raised when content verification fails on a censored node
 
     Also contains the tombstone data substituted for the uncensored data.
     """
 
     def __init__(self, filename, node, tombstone):
         from node import short
         RevlogError.__init__(self, '%s:%s' % (filename, short(node)))
         self.tombstone = tombstone
 
 class CensoredBaseError(RevlogError):
     """error raised when a delta is rejected because its base is censored
 
     A delta based on a censored revision must be formed as single patch
     operation which replaces the entire base with new content. This ensures
     the delta may be applied by clones which have not censored the base.
     """