def build(self):
'''
Construct the parser.
'''
# Avoid dependency loops
from lepl.matchers.derived import Drop, Eos, AnyBut, Upper
from lepl.matchers.core import Any, Lookahead, Literal, Delayed
from lepl.matchers.error import make_error
from lepl.matchers.variables import TraceVariables
from lepl.support.node import node_throw
with TraceVariables(False):
# these two definitions enforce the conditions above, providing only
# special characters appear as literals in the grammar
escaped = Drop(self.alphabet.escape) & self.alphabet.escaped
raw = ~Lookahead(self.alphabet.escape) & \
AnyBut(self.alphabet.illegal)
close = Drop(')')
extend = (Drop('(*') & Upper()[1:,...] & close) >> self.extend
single = escaped | raw | extend
any_ = Literal('.') >> self.dot
letter = single >> self.dup
pair = single & Drop('-') & single > self.tup
interval = pair | letter
brackets = Drop('[') & interval[1:] & Drop(']')
inverted = Drop('[^') & interval[1:] & Drop(']') >= self.invert
char = inverted | brackets | letter | any_ | extend > self.char
item = Delayed()
open = Drop('(?:')
range = Drop(self.alphabet.escape) & self.alphabet.range
seq = (char | item | range)[0:] > self.sequence
group = open & seq & close
alts = open & seq[2:, Drop('|')] & close > self.choice
star = (alts | group | char) & Drop('*') > self.star
plus = (alts | group | char) & Drop('+') > self.plus
opt = (alts | group | char) & Drop('?') > self.option
bad_grp = (Drop('(') & ~Lookahead('?:') & seq & close) \
** make_error(
"Lepl's own regular expressions do not currently "
"support matched groups.\n"
"Use '(?:...)' to group expressions without "
"matching.")
item += alts | group | star | plus | opt | bad_grp
expr = ((char | item)[:] & Drop(Eos())) >> node_throw
# Empty config here avoids loops if the default config includes
# references to alphabets
expr.config.clear()
return expr.parse_string
def build(self):
'''
Construct the parser.
'''
# Avoid dependency loops
from lepl.matchers.derived import Drop, Eos, AnyBut, Upper
from lepl.matchers.core import Any, Lookahead, Literal, Delayed
from lepl.matchers.error import make_error
from lepl.matchers.variables import TraceVariables
from lepl.support.node import node_throw
with TraceVariables(False):
# these two definitions enforce the conditions above, providing only
# special characters appear as literals in the grammar
escaped = Drop(self.alphabet.escape) & self.alphabet.escaped
raw = ~Lookahead(self.alphabet.escape) & \
AnyBut(self.alphabet.illegal)
close = Drop(')')
extend = (Drop('(*') & Upper()[1:, ...] & close) >> self.extend
single = escaped | raw | extend
any_ = Literal('.') >> self.dot
letter = single >> self.dup
pair = single & Drop('-') & single > self.tup
interval = pair | letter
brackets = Drop('[') & interval[1:] & Drop(']')
inverted = Drop('[^') & interval[1:] & Drop(']') >= self.invert
char = inverted | brackets | letter | any_ | extend > self.char
item = Delayed()
open = Drop('(?:')
range = Drop(self.alphabet.escape) & self.alphabet.range
seq = (char | item | range)[0:] > self.sequence
group = open & seq & close
alts = open & seq[2:, Drop('|')] & close > self.choice
star = (alts | group | char) & Drop('*') > self.star
plus = (alts | group | char) & Drop('+') > self.plus
opt = (alts | group | char) & Drop('?') > self.option
bad_grp = (Drop('(') & ~Lookahead('?:') & seq & close) \
** make_error(
"Lepl's own regular expressions do not currently "
"support matched groups.\n"
"Use '(?:...)' to group expressions without "
"matching.")
item += alts | group | star | plus | opt | bad_grp
expr = ((char | item)[:] & Drop(Eos())) >> node_throw
# Empty config here avoids loops if the default config includes
# references to alphabets
expr.config.clear()
return expr.parse_string
def test_bad_format(self):
'''
Test a message with bad formatting.
'''
try:
parser = (Literal('abc') > 'name')**make_error('msg {0}')
parser.config.no_full_first_match()
list(parser.match('abc'))
assert False, 'expected error'
except IndexError:
pass
def test_formatted(self):
'''
Test a message with formatting.
'''
parser = (Literal('abc') > 'name')**make_error('msg {stream_in}')
parser.config.no_full_first_match()
node = parser.parse('abc')[0]
assert isinstance(node, Error)
assert node[0] == 'msg abc', node[0]
assert str(node).startswith('msg abc ('), str(node)
assert isinstance(node, Exception), type(node)
def test_bad_format(self):
'''
Test a message with bad formatting.
'''
try:
parser = (Literal('abc') > 'name') ** make_error('msg {0}')
parser.config.no_full_first_match()
list(parser.match('abc'))
assert False, 'expected error'
except IndexError:
pass
def test_formatted(self):
'''
Test a message with formatting.
'''
parser = (Literal('abc') > 'name') ** make_error('msg {stream_in}')
parser.config.no_full_first_match()
node = parser.parse('abc')[0]
assert isinstance(node, Error)
assert node[0] == 'msg abc', node[0]
assert str(node).startswith('msg abc ('), str(node)
assert isinstance(node, Exception), type(node)
def test_fmtted(self):
'''
Test a message with fmtting.
'''
parser = (Literal('abc') > 'name')**make_error('msg {in_rest}')
parser.config.no_full_first_match()
node = parser.parse('abc')[0]
assert isinstance(node, Error)
assert node[0] == "msg 'abc'", node[0]
assert str(node).startswith("msg 'abc' ("), str(node)
assert isinstance(node, Exception), type(node)
def test_fmtted(self):
'''
Test a message with fmtting.
'''
parser = (Literal('abc') > 'name') ** make_error('msg {in_rest}')
parser.config.no_full_first_match()
node = parser.parse('abc')[0]
assert isinstance(node, Error)
assert node[0] == "msg 'abc'", node[0]
assert str(node).startswith("msg 'abc' ("), str(node)
assert isinstance(node, Exception), type(node)
def test_list(self):
'''
Code has an exception for handling lists.
'''
#basicConfig(level=DEBUG)
with TraceVariables():
parser = (Literal([1, 2, 3]) > 'name')**make_error('msg {in_str}')
parser.config.no_full_first_match()
node = parser.parse([1, 2, 3])[0]
assert isinstance(node, Error)
assert node[0] == 'msg 1', node[0]
assert str(node).startswith('msg 1 ('), str(node)
assert isinstance(node, Exception), type(node)
def test_list(self):
'''
Code has an exception for handling lists.
'''
#basicConfig(level=DEBUG)
with TraceVariables():
parser = (Literal([1, 2, 3]) > 'name') ** make_error('msg {stream_in}')
parser.config.no_full_first_match()
node = parser.parse([1, 2, 3])[0]
assert isinstance(node, Error)
assert node[0] == 'msg [1, 2, 3]', node[0]
assert str(node).startswith('msg [1, 2, 3] ('), str(node)
assert isinstance(node, Exception), type(node)