def repl(repls, value):

    '''Raises error if value not in map and no special '*' entry

    @param repls dict repl:with

        repl "*" means all other input values

        with "*" means keep input value the same

        with "" means ignore input value

    '''

    try: new_value = repls[value]

    except KeyError, e:

        # Save traceback right away in case another exception raised

        fe = FormatException(e)

        try: new_value = repls['*']

        except KeyError: raise fe

    if new_value == '*': new_value = value # '*' means keep input value the same

    return new_value

def _map(items, node):

    '''See repl()

    @param items

        <last_entry> Value

        <other_entries> name=value Mappings. Special values: See repl() repls.

    '''

    value = pop_value(items)

    if value == None: return None # input is empty

    return util.none_if(repl(dict(items), value), u'') # empty value means None

funcs['_map'] = _map