mirror of
git://projects.qi-hardware.com/openwrt-packages.git
synced 2024-11-23 18:12:47 +02:00
70 lines
2.0 KiB
Python
70 lines
2.0 KiB
Python
|
"""Iterator based sre token scanner
|
||
|
|
|
||
|
|
"""
|
||
|
|
|
||
|
|
import re
|
||
|
|
import sre_parse
|
||
|
|
import sre_compile
|
||
|
|
import sre_constants
|
||
|
|
|
||
|
|
from re import VERBOSE, MULTILINE, DOTALL
|
||
|
|
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
|