# Copyright 2010 Matt Chaput. All rights reserved.
#
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# modification, are permitted provided that the following conditions are met:
#
#    1. Redistributions of source code must retain the above copyright notice,
#       this list of conditions and the following disclaimer.
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#    2. Redistributions in binary form must reproduce the above copyright
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#       documentation and/or other materials provided with the distribution.
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# THIS SOFTWARE IS PROVIDED BY MATT CHAPUT ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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# EVENT SHALL MATT CHAPUT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
# OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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# policies, either expressed or implied, of Matt Chaput.

"""
This module contains common utility objects/functions for the other query
parser modules.
"""

import sys

from whoosh.compat import string_type


class QueryParserError(Exception):
    def __init__(self, cause, msg=None):
        super(QueryParserError, self).__init__(str(cause))
        self.cause = cause


def get_single_text(field, text, **kwargs):
    """Returns the first token from an analyzer's output.
    """

    for t in field.process_text(text, mode="query", **kwargs):
        return t


def attach(q, stxnode):
    if q:
        try:
            q.startchar = stxnode.startchar
            q.endchar = stxnode.endchar
        except AttributeError:
            raise AttributeError("Can't set attribute on %s"
                                 % q.__class__.__name__)
    return q


def print_debug(level, msg, out=sys.stderr):
    if level:
        out.write("%s%s\n" % (" " * (level - 1), msg))