app/django/utils/simplejson/scanner.py
author Sverre Rabbelier <srabbelier@gmail.com>
Sun, 01 Feb 2009 22:48:48 +0000
changeset 1166 558bd62ee9d4
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Fix get args construction when there are multiple lists on the page It is now possible to go back and forward through the liast, and specify the limit (both offset and limit can be done per list). The JS driving the list boxes is buggy, if visiting an url like: http://localhost:8080/notification/list?limit_0=10 And then change the limit in the second checkbox, it directs to: http://localhost:8080/notification/list?limit_1=25 Whereas it should redirect to: http://localhost:8080/notification/list?limit_0=10&limit_1=25 The logic _does_ work properly when the limit of the changed list is already present in the url. Patch by: Sverre Rabbelier

"""
Iterator based sre token scanner
"""
import re
from re import VERBOSE, MULTILINE, DOTALL
import sre_parse
import sre_compile
import sre_constants
from sre_constants import BRANCH, SUBPATTERN

__all__ = ['Scanner', 'pattern']

FLAGS = (VERBOSE | MULTILINE | DOTALL)

class Scanner(object):
    def __init__(self, lexicon, flags=FLAGS):
        self.actions = [None]
        # Combine phrases into a compound pattern
        s = sre_parse.Pattern()
        s.flags = flags
        p = []
        for idx, token in enumerate(lexicon):
            phrase = token.pattern
            try:
                subpattern = sre_parse.SubPattern(s,
                    [(SUBPATTERN, (idx + 1, sre_parse.parse(phrase, flags)))])
            except sre_constants.error:
                raise
            p.append(subpattern)
            self.actions.append(token)

        s.groups = len(p) + 1 # NOTE(guido): Added to make SRE validation work
        p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
        self.scanner = sre_compile.compile(p)

    def iterscan(self, string, idx=0, context=None):
        """
        Yield match, end_idx for each match
        """
        match = self.scanner.scanner(string, idx).match
        actions = self.actions
        lastend = idx
        end = len(string)
        while True:
            m = match()
            if m is None:
                break
            matchbegin, matchend = m.span()
            if lastend == matchend:
                break
            action = actions[m.lastindex]
            if action is not None:
                rval, next_pos = action(m, context)
                if next_pos is not None and next_pos != matchend:
                    # "fast forward" the scanner
                    matchend = next_pos
                    match = self.scanner.scanner(string, matchend).match
                yield rval, matchend
            lastend = matchend


def pattern(pattern, flags=FLAGS):
    def decorator(fn):
        fn.pattern = pattern
        fn.regex = re.compile(pattern, flags)
        return fn
    return decorator