def parse_query(expr_str):
def parse_terminal(pstate):
next_tag = pstate.next_tag()
if next_tag is _tag:
return make_tag_query(pstate.next_str_and_advance())
elif next_tag is _negtag:
return NotQuery(make_tag_query(pstate.next_str_and_advance()[1:]))
elif next_tag is _fulltext:
return FulltextQuery(pstate.next_str_and_advance()[1:-1])
elif next_tag is _dated:
pstate.advance()
return DatedQuery()
elif next_tag in _STATELESS_TERMINALS:
pstate.advance()
return _STATELESS_TERMINALS[next_tag]
elif next_tag in [_id]:
result = IdQuery(int(pstate.next_match_obj().group(1)))
pstate.advance()
return result
elif next_tag in [_before, _after]:
from parsedatetime.parsedatetime import Calendar
cal = Calendar()
timetup = cal.parse(pstate.next_match_obj().group(1))
pstate.advance()
import time
return DateQuery(next_tag == _before, time.mktime(timetup[0]))
else:
pstate.expected("terminal")
def inner_parse(pstate, min_precedence=0):
pstate.expect_not_end()
if pstate.is_next(_not):
pstate.advance()
left_query = make_not_query(inner_parse(pstate, _PREC_NOT))
elif pstate.is_next(_openpar):
pstate.advance()
left_query = inner_parse(pstate)
pstate.expect(_closepar)
pstate.advance()
else:
left_query = parse_terminal(pstate)
did_something = True
while did_something:
did_something = False
if pstate.is_at_end():
return left_query
next_tag = pstate.next_tag()
if next_tag is _and and _PREC_AND > min_precedence:
pstate.advance()
left_query = make_and_query(
[left_query, inner_parse(pstate, _PREC_AND)])
did_something = True
elif next_tag is _or and _PREC_OR > min_precedence:
pstate.advance()
left_query = make_or_query(
[left_query, inner_parse(pstate, _PREC_OR)])
did_something = True
elif (next_tag in _TERMINALS + [_not, _openpar]
and _PREC_AND > min_precedence):
left_query = make_and_query(
[left_query, inner_parse(pstate, _PREC_AND)])
did_something = True
return left_query
from pytools.lex import LexIterator, lex
pstate = LexIterator(
[(tag, s, idx, matchobj)
for (tag, s, idx,
matchobj) in lex(_LEX_TABLE, expr_str, match_objects=True)
if tag is not _whitespace], expr_str)
if pstate.is_at_end():
return TagQuery(u"home")
result = inner_parse(pstate)
if not pstate.is_at_end():
pstate.raise_parse_error("leftover input after completed parse")
return result
def parse_query(course, expr_str):
from django.db.models import Q
def parse_terminal(pstate):
next_tag = pstate.next_tag()
if next_tag is _id:
result = Q(user__id=int(pstate.next_match_obj().group(1)))
pstate.advance()
return result
elif next_tag is _email:
result = Q(user__email__iexact=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _email_contains:
result = Q(user__email__icontains=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _user:
result = Q(user__username__exact=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _user_contains:
result = Q(
user__username__contains=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _institutional_id:
result = Q(user__institutional_id__iexact=pstate.next_match_obj().
group(1))
pstate.advance()
return result
elif next_tag is _institutional_id_contains:
result = Q(user__institutional_id__icontains=pstate.next_match_obj(
).group(1))
pstate.advance()
return result
elif next_tag is _tagged:
ptag, created = ParticipationTag.objects.get_or_create(
course=course, name=pstate.next_match_obj().group(1))
result = Q(tags__pk=ptag.pk)
pstate.advance()
return result
elif next_tag is _role:
result = Q(role=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _status:
result = Q(status=pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _has_started:
flow_id = pstate.next_match_obj().group(1)
result = (Q(flow_sessions__flow_id=flow_id)
& Q(flow_sessions__course=course))
pstate.advance()
return result
elif next_tag is _has_submitted:
flow_id = pstate.next_match_obj().group(1)
result = (Q(flow_sessions__flow_id=flow_id)
& Q(flow_sessions__course=course)
& Q(flow_sessions__in_progress=False))
pstate.advance()
return result
else:
pstate.expected("terminal")
def inner_parse(pstate, min_precedence=0):
pstate.expect_not_end()
if pstate.is_next(_not):
pstate.advance()
left_query = ~inner_parse(pstate, _PREC_NOT)
elif pstate.is_next(_openpar):
pstate.advance()
left_query = inner_parse(pstate)
pstate.expect(_closepar)
pstate.advance()
else:
left_query = parse_terminal(pstate)
did_something = True
while did_something:
did_something = False
if pstate.is_at_end():
return left_query
next_tag = pstate.next_tag()
if next_tag is _and and _PREC_AND > min_precedence:
pstate.advance()
left_query = left_query & inner_parse(pstate, _PREC_AND)
did_something = True
elif next_tag is _or and _PREC_OR > min_precedence:
pstate.advance()
left_query = left_query | inner_parse(pstate, _PREC_OR)
did_something = True
elif (next_tag in _TERMINALS + [_not, _openpar]
and _PREC_AND > min_precedence):
left_query = left_query & inner_parse(pstate, _PREC_AND)
did_something = True
return left_query
from pytools.lex import LexIterator, lex
pstate = LexIterator(
[(tag, s, idx, matchobj)
for (tag, s, idx,
matchobj) in lex(_LEX_TABLE, expr_str, match_objects=True)
if tag is not _whitespace], expr_str)
if pstate.is_at_end():
pstate.raise_parse_error("unexpected end of input")
result = inner_parse(pstate)
if not pstate.is_at_end():
pstate.raise_parse_error("leftover input after completed parse")
return result
def parse_match(expr):
"""Syntax examples::
* ``id:yoink and writes:a_temp``
* ``id:yoink and (not writes:a_temp or tag:input)``
"""
if not expr:
return All()
def parse_terminal(pstate):
next_tag = pstate.next_tag()
if next_tag is _id:
result = Id(pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _tag:
result = Tagged(pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _writes:
result = Writes(pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _reads:
result = Reads(pstate.next_match_obj().group(1))
pstate.advance()
return result
elif next_tag is _iname:
result = Iname(pstate.next_match_obj().group(1))
pstate.advance()
return result
else:
pstate.expected("terminal")
def inner_parse(pstate, min_precedence=0):
pstate.expect_not_end()
if pstate.is_next(_not):
pstate.advance()
left_query = Not(inner_parse(pstate, _PREC_NOT))
elif pstate.is_next(_openpar):
pstate.advance()
left_query = inner_parse(pstate)
pstate.expect(_closepar)
pstate.advance()
else:
left_query = parse_terminal(pstate)
did_something = True
while did_something:
did_something = False
if pstate.is_at_end():
return left_query
next_tag = pstate.next_tag()
if next_tag is _and and _PREC_AND > min_precedence:
pstate.advance()
left_query = And((left_query, inner_parse(pstate, _PREC_AND)))
did_something = True
elif next_tag is _or and _PREC_OR > min_precedence:
pstate.advance()
left_query = Or((left_query, inner_parse(pstate, _PREC_OR)))
did_something = True
return left_query
if isinstance(expr, MatchExpressionBase):
return expr
from pytools.lex import LexIterator, lex, InvalidTokenError
try:
pstate = LexIterator(
[(tag, s, idx, matchobj)
for (tag, s, idx,
matchobj) in lex(_LEX_TABLE, expr, match_objects=True)
if tag is not _whitespace], expr)
except InvalidTokenError as e:
from loopy.diagnostic import LoopyError
raise LoopyError(
"invalid match expression: '{match_expr}' ({err_type}: {err_str})".
format(match_expr=expr, err_type=type(e).__name__, err_str=str(e)))
if pstate.is_at_end():
pstate.raise_parse_error("unexpected end of input")
result = inner_parse(pstate)
if not pstate.is_at_end():
pstate.raise_parse_error("leftover input after completed parse")
return result
