"""
# Python imports
-import os.path
+import os
import pickle
import tempfile
+from typing import Any, Dict, List, Optional, Text, Tuple, TypeVar, Union
# Local imports
from . import token
+_P = TypeVar("_P", bound="Grammar")
+Label = Tuple[int, Optional[Text]]
+DFA = List[List[Tuple[int, int]]]
+DFAS = Tuple[DFA, Dict[int, int]]
+Path = Union[str, "os.PathLike[str]"]
+
class Grammar(object):
"""Pgen parsing tables conversion class.
"""
- def __init__(self):
- self.symbol2number = {}
- self.number2symbol = {}
- self.states = []
- self.dfas = {}
- self.labels = [(0, "EMPTY")]
- self.keywords = {}
- self.tokens = {}
- self.symbol2label = {}
+ def __init__(self) -> None:
+ self.symbol2number: Dict[str, int] = {}
+ self.number2symbol: Dict[int, str] = {}
+ self.states: List[DFA] = []
+ self.dfas: Dict[int, DFAS] = {}
+ self.labels: List[Label] = [(0, "EMPTY")]
+ self.keywords: Dict[str, int] = {}
+ self.tokens: Dict[int, int] = {}
+ self.symbol2label: Dict[str, int] = {}
self.start = 256
+ # Python 3.7+ parses async as a keyword, not an identifier
+ self.async_keywords = False
- def dump(self, filename):
+ def dump(self, filename: Path) -> None:
"""Dump the grammar tables to a pickle file."""
- with tempfile.NamedTemporaryFile(dir=os.path.dirname(filename), delete=False) as f:
- pickle.dump(self.__dict__, f, pickle.HIGHEST_PROTOCOL)
+
+ # mypyc generates objects that don't have a __dict__, but they
+ # do have __getstate__ methods that will return an equivalent
+ # dictionary
+ if hasattr(self, "__dict__"):
+ d = self.__dict__
+ else:
+ d = self.__getstate__() # type: ignore
+
+ with tempfile.NamedTemporaryFile(
+ dir=os.path.dirname(filename), delete=False
+ ) as f:
+ pickle.dump(d, f, pickle.HIGHEST_PROTOCOL)
os.replace(f.name, filename)
- def load(self, filename):
+ def _update(self, attrs: Dict[str, Any]) -> None:
+ for k, v in attrs.items():
+ setattr(self, k, v)
+
+ def load(self, filename: Path) -> None:
"""Load the grammar tables from a pickle file."""
with open(filename, "rb") as f:
d = pickle.load(f)
- self.__dict__.update(d)
+ self._update(d)
- def loads(self, pkl):
+ def loads(self, pkl: bytes) -> None:
"""Load the grammar tables from a pickle bytes object."""
- self.__dict__.update(pickle.loads(pkl))
+ self._update(pickle.loads(pkl))
- def copy(self):
+ def copy(self: _P) -> _P:
"""
Copy the grammar.
"""
new = self.__class__()
- for dict_attr in ("symbol2number", "number2symbol", "dfas", "keywords",
- "tokens", "symbol2label"):
+ for dict_attr in (
+ "symbol2number",
+ "number2symbol",
+ "dfas",
+ "keywords",
+ "tokens",
+ "symbol2label",
+ ):
setattr(new, dict_attr, getattr(self, dict_attr).copy())
new.labels = self.labels[:]
new.states = self.states[:]
new.start = self.start
+ new.async_keywords = self.async_keywords
return new
- def report(self):
+ def report(self) -> None:
"""Dump the grammar tables to standard output, for debugging."""
from pprint import pprint
+
print("s2n")
pprint(self.symbol2number)
print("n2s")
// DOUBLESLASH
//= DOUBLESLASHEQUAL
-> RARROW
+:= COLONEQUAL
"""
opmap = {}