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tags/v1.0^2
Ben Kurtovic 10 jaren geleden
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commit
9c867b4dc3
1 gewijzigde bestanden met toevoegingen van 103 en 6 verwijderingen
  1. +103
    -6
      bitshift/query/__init__.py

+ 103
- 6
bitshift/query/__init__.py Bestand weergeven

@@ -5,7 +5,7 @@ frontend into trees that can be used by the database backend.

from __future__ import unicode_literals
from re import IGNORECASE, search
from shlex import split
from sys import maxsize

from dateutil.parser import parse as parse_date

@@ -146,12 +146,109 @@ class _QueryParser(object):

:raises: :py:class:`.QueryParseException`
"""
root = None
## TODO: balance tree
## --------------------------------------------------------------------

def SCAN_FOR_MARKER(string, markers):
best_marker, best_index = None, maxsize
for marker in markers:
index = string.find(marker)
if index > 0 and string[index - 1] == "\\" and (index == 1 or string[index - 2] != "\\"):
_, new_index = SCAN_FOR_MARKER(string[index + 1:], marker)
index += new_index + 1
if index >= 0 and index < best_index:
best_marker, best_index = marker, index
return best_marker, best_index

def SPLIT_QUERY_STRING(string, parens=False):
string = string.lstrip()
if not string:
return []
marker, index = SCAN_FOR_MARKER(string, " \"'()")

if not marker:
return [string]

before = [string[:index]] if index > 0 else []
after = string[index + 1:]

if marker == " ":
return before + SPLIT_QUERY_STRING(after, parens)

elif marker in ('"', "'"):
close_marker, close_index = SCAN_FOR_MARKER(after, marker)
if not close_marker:
return before + [after]
quoted, after = after[:close_index], after[close_index + 1:]
return before + [quoted] + SPLIT_QUERY_STRING(after, parens)

elif marker == "(":
inner = SPLIT_QUERY_STRING(after, True)
if inner and isinstance(inner[-1], tuple):
after, inner = inner.pop()[0], [inner] if inner else []
return before + inner + SPLIT_QUERY_STRING(after, parens)
return before + [inner]

elif marker == ")":
if parens:
return before + [(after,)]
return before + SPLIT_QUERY_STRING(after)

nest = SPLIT_QUERY_STRING(query.rstrip())
if not nest:
raise QueryParseException('Empty query: "%s"' % query)

return nest

###########

group = _NodeGroup()
for term in split(query):
node = self._parse_term(term)
root = BinaryOp(root, BinaryOp.AND, node) if root else node
tree = Tree(root)
return tree

while term.startswith("("):
group = _NodeList(group, explicit=True)
term = term[1:]

closes = 0
while term.endswith(")"):
closes += 1
term = term[:-1]

if not term:
for i in xrange(closes):
group = reduce_group(group, explicit=True)
continue

lcase = term.lower()

if lcase == "not":
UnaryOp.NOT
elif lcase == "or":
BinaryOp.OR
elif lcase == "and":
if group.pending_op:
pass
else:
group.pending_op = BinaryOP.AND
else:
group.nodes.append(self._parse_term(term))

return Tree(reduce_group(group, explicit=False))

## --------------------------------------------------------------------

# root = None
# for node in reversed(nodes):
# root = BinaryOp(node, BinaryOp.AND, root) if root else node
# tree = Tree(root)
# return tree

class _NodeGroup(object):
def __init__(self, parent=None):
self.parent = parent
self.op = None
self.left = None
self.right = None


parse_query = _QueryParser().parse

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