def Choice(*expressions: _Def):
exprs = list(map(_validate, expressions))
if len(exprs) == 1:
return exprs[0]
else:
_exprs: List[Definition] = []
for expr in exprs:
if expr.op == CHC:
_exprs.extend(expr.args[0])
else:
_exprs.append(expr)
return Definition(CHC, (_exprs, ))
def Class(arg, negate: bool = False):
ranges: List[Tuple[str, Union[str, None]]]
if isinstance(arg, list):
ranges = arg
else:
assert isinstance(arg, str)
ranges = []
i = 0
while i < len(arg) - 2:
if arg[i + 1] == '-':
ranges.append((arg[i], arg[i + 2]))
i += 3
else:
ranges.append((arg[i], None))
i += 1
while i < len(arg):
ranges.append((arg[i], None))
i += 1
return Definition(CLS, (ranges, negate))
def Regex(pattern: Union[str, Pattern], flags: int = 0):
return Definition(RGX, (pattern, flags))
def Literal(string: str):
return Definition(LIT, (string, ))
def Debug(expression: _Def):
return Definition(DBG, (_validate(expression), ))
def Dot():
return Definition(DOT, ())
def Bind(expression: _Def, name: str):
assert isinstance(name, str)
return Definition(BND, (_validate(expression), name))
def Rule(expression: _Def, action: Callable, name: str = ANONYMOUS):
if action and not isinstance(action, Action):
action = Call(action)
return Definition(RUL, (_validate(expression), action, name))
def Not(expression: _Def):
return Definition(NOT, (_validate(expression), ))
def Capture(expression: _Def):
return Definition(CAP, (_validate(expression), ))
def And(expression: _Def):
return Definition(AND, (_validate(expression), ))
def Nonterminal(name: str):
return Definition(SYM, (name, ))
def Plus(expression: _Def):
expression = _validate(expression)
if expression.op in (OPT, STR, PLS):
raise GrammarError('multiple repeat operators')
return Definition(PLS, (expression, ))
def _debug_combining(defn: Definition, defs):
inner = [_debug(sub, defs) for sub in defn.args[0]]
dbg_defn = Definition(defn.op, (inner, ) + defn.args[1:])
return Debug(dbg_defn)
def _debug_recursive(defn: Definition, defs):
inner = _debug(defn.args[0], defs)
dbg_defn = Definition(defn.op, (inner, ) + defn.args[1:])
return Debug(dbg_defn)