def __init__(self, grammar, ruleName, callback=None, globals=None):
self.grammar = grammar
self.position = 0
self.callback = callback
self.globals = globals or {}
self.rules = decomposeGrammar(grammar)
self.next = self.apply(ruleName, None, ())
self._localsStack = []
self.currentResult = None
self.input = InputStream([], 0)
self.ended = False
v, err = self._eval(run, args[1])
self._localsStack[-1][args[0].data] = v
return v, err
elif name == "Predicate":
val, err = self._eval(run, args[0])
if not val:
raise err
else:
return True, err
elif name == "List":
v, e = run.rule_anything()
oldInput = run.input
try:
run.input = InputStream.fromIterable(v)
except TypeError:
raise e.withMessage(expected("an iterable"))
self._eval(run, args[0])
run.end()
run.input = oldInput
return v, e
elif name in ("Action", "Python"):
lo = self._localsStack[-1]
val = eval(args[0].data, self._globals, lo)
return (val, run.input.nullError())
elif name == "ConsumedBy":
oldInput = run.input
_, err = self._eval(run, args[0])
def _eval(self, run, expr):
name = expr.tag.name
args = expr.args
if name == "Apply":
ruleName = args[0].data
return self._apply(run, ruleName, args[2].args)
elif name == "Exactly":
return run.exactly(args[0].data)
elif name == "Label":
label = args[1].data
try:
val, err = self._eval(run, args[0])
return val, err.withMessage([("Custom Exception:", label, None)])
except ParseError as err:
e=err
raise e.withMessage([("Custom Exception:", label, None)])
elif name == "Token":
if run.tree:
return run._apply(run.rule_exactly, "exactly", [args[0].data])
else:
return run._apply(run.rule_token, "token", [args[0].data])
elif name in ("Many", "Many1"):
ans = [self._eval(run, args[0])[0]] if name == "Many1" else []
err = None
while True:
try:
m = run.input
v, _ = self._eval(run, args[0])
ans.append(v)
except ParseError as e:
err = e
run.input = m
break
return ans, err
elif name == "Repeat":
if args[0].tag.name == '.int.':
min = args[0].data
else:
min = self._localsStack[-1][args[0].data]
if args[1].tag.name == '.int.':
max = args[1].data
elif args[1].tag.name == 'null':
max = None
else:
max = self._localsStack[-1][args[1].data]
if min == max == 0:
return "", None
ans = []
e = None
for i in range(min):
v, e = self._eval(run, args[2])
ans.append(v)
for i in range(min, max):
try:
m = run.input
v, e = self._eval(run, args[2])
ans.append(v)
except ParseError as err:
e = err
run.input = m
break
return ans, e
elif name == "Optional":
i = run.input
try:
return self._eval(run, args[0])
except ParseError:
run.input = i
return (None, run.input.nullError())
elif name == "Or":
errors = []
for e in args[0].args:
try:
m = run.input
x = self._eval(run, e)
ret, err = x
errors.append(err)
return ret, joinErrors(errors)
except ParseError as err:
errors.append(err)
run.input = m
raise joinErrors(errors)
elif name == "Not":
m = run.input
try:
self._eval(run, args[0])
except ParseError as err:
run.input = m
return True, run.input.nullError()
else:
raise run.input.nullError()
elif name == "Lookahead":
try:
m = run.input
return self._eval(run, args[0])
finally:
run.input = m
elif name == "And":
v = None, run.input.nullError()
for e in args[0].args:
v = self._eval(run, e)
return v
elif name == "Bind":
v, err = self._eval(run, args[1])
if args[0].data:
self._localsStack[-1][args[0].data] = v
else:
for n, val in zip(args[0].args, v):
self._localsStack[-1][n.data] = val
return v, err
elif name == "Predicate":
val, err = self._eval(run, args[0])
if not val:
raise err
else:
return True, err
elif name == "List":
v, e = run.rule_anything()
oldInput = run.input
try:
run.input = InputStream.fromIterable(v)
except TypeError:
raise e.withMessage(expected("an iterable"))
self._eval(run, args[0])
run.end()
run.input = oldInput
return v, e
elif name in ("Action", "Python"):
lo = self._localsStack[-1]
val = eval(args[0].data, self._globals, lo)
return (val, run.input.nullError())
elif name == "ConsumedBy":
oldInput = run.input
_, err = self._eval(run, args[0])
slice = oldInput.data[oldInput.position:run.input.position]
return slice, err
else:
raise ValueError("Unrecognized term: %r" % (name,))
v, err = self._eval(run, args[1])
self._localsStack[-1][args[0].data] = v
return v, err
elif name == "Predicate":
val, err = self._eval(run, args[0])
if not val:
raise err
else:
return True, err
elif name == "List":
v, e = run.rule_anything()
oldInput = run.input
try:
run.input = InputStream.fromIterable(v)
except TypeError:
raise e.withMessage(expected("an iterable"))
self._eval(run, args[0])
run.end()
run.input = oldInput
return v, e
elif name in ("Action", "Python"):
lo = self._localsStack[-1]
val = eval(args[0].data, self._globals, lo)
return (val, run.input.nullError())
elif name == "ConsumedBy":
oldInput = run.input
_, err = self._eval(run, args[0])
def makeTokenStream(text, origin="<string>"):
lexer = MonteLexer(StringFeeder(text, origin))
toks = [tok for tok in lexer if tok.tag.name != '#'
and tok.tag.name != 'UPDOC']
return InputStream.fromIterable(toks)
def _eval(self, run, expr):
name = expr.tag.name
args = expr.args
if name == "Apply":
ruleName = args[0].data
return self._apply(run, ruleName, args[2].args)
elif name == "Exactly":
return run.exactly(args[0].data)
elif name == "Label":
label = args[1].data
try:
val, err = self._eval(run, args[0])
return val, err.withMessage([("Custom Exception:", label, None)
])
except ParseError as err:
e = err
raise e.withMessage([("Custom Exception:", label, None)])
elif name == "Token":
if run.tree:
return run._apply(run.rule_exactly, "exactly", [args[0].data])
else:
return run._apply(run.rule_token, "token", [args[0].data])
elif name in ("Many", "Many1"):
ans = [self._eval(run, args[0])[0]] if name == "Many1" else []
err = None
while True:
try:
m = run.input
v, _ = self._eval(run, args[0])
ans.append(v)
except ParseError as e:
err = e
run.input = m
break
return ans, err
elif name == "Repeat":
if args[0].tag.name == '.int.':
min = args[0].data
else:
min = self._localsStack[-1][args[0].data]
if args[1].tag.name == '.int.':
max = args[1].data
elif args[1].tag.name == 'null':
max = None
else:
max = self._localsStack[-1][args[1].data]
if min == max == 0:
return "", None
ans = []
e = None
for i in range(min):
v, e = self._eval(run, args[2])
ans.append(v)
for i in range(min, max):
try:
m = run.input
v, e = self._eval(run, args[2])
ans.append(v)
except ParseError as err:
e = err
run.input = m
break
return ans, e
elif name == "Optional":
i = run.input
try:
return self._eval(run, args[0])
except ParseError:
run.input = i
return (None, run.input.nullError())
elif name == "Or":
errors = []
for e in args[0].args:
try:
m = run.input
x = self._eval(run, e)
ret, err = x
errors.append(err)
return ret, joinErrors(errors)
except ParseError as err:
errors.append(err)
run.input = m
raise joinErrors(errors)
elif name == "Not":
m = run.input
try:
self._eval(run, args[0])
except ParseError as err:
run.input = m
return True, run.input.nullError()
else:
raise run.input.nullError()
elif name == "Lookahead":
try:
m = run.input
return self._eval(run, args[0])
finally:
run.input = m
elif name == "And":
v = None, run.input.nullError()
for e in args[0].args:
v = self._eval(run, e)
return v
elif name == "Bind":
v, err = self._eval(run, args[1])
if args[0].data:
self._localsStack[-1][args[0].data] = v
else:
for n, val in zip(args[0].args, v):
self._localsStack[-1][n.data] = val
return v, err
elif name == "Predicate":
val, err = self._eval(run, args[0])
if not val:
raise err
else:
return True, err
elif name == "List":
v, e = run.rule_anything()
oldInput = run.input
try:
run.input = InputStream.fromIterable(v)
except TypeError:
raise e.withMessage(expected("an iterable"))
self._eval(run, args[0])
run.end()
run.input = oldInput
return v, e
elif name in ("Action", "Python"):
lo = self._localsStack[-1]
val = eval(args[0].data, self._globals, lo)
return (val, run.input.nullError())
elif name == "ConsumedBy":
oldInput = run.input
_, err = self._eval(run, args[0])
slice = oldInput.data[oldInput.position:run.input.position]
return slice, err
else:
raise ValueError("Unrecognized term: %r" % (name, ))
def makeTokenStream(text, origin="<string>"):
lexer = MonteLexer(StringFeeder(text, origin))
toks = [tok for tok in lexer if tok.tag.name != '#'
and tok.tag.name != 'UPDOC']
return InputStream.fromIterable(toks)