X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/3f68af9813542a5e277b7a51b316644241c372d7..dc71922c768e543c9c3bbb1db5ea6d7fa801a814:/.vim/bundle/black/src/blib2to3/pgen2/grammar.py diff --git a/.vim/bundle/black/src/blib2to3/pgen2/grammar.py b/.vim/bundle/black/src/blib2to3/pgen2/grammar.py new file mode 100644 index 0000000..2882cda --- /dev/null +++ b/.vim/bundle/black/src/blib2to3/pgen2/grammar.py @@ -0,0 +1,223 @@ +# Copyright 2004-2005 Elemental Security, Inc. All Rights Reserved. +# Licensed to PSF under a Contributor Agreement. + +"""This module defines the data structures used to represent a grammar. + +These are a bit arcane because they are derived from the data +structures used by Python's 'pgen' parser generator. + +There's also a table here mapping operators to their names in the +token module; the Python tokenize module reports all operators as the +fallback token code OP, but the parser needs the actual token code. + +""" + +# Python imports +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. + + Once initialized, this class supplies the grammar tables for the + parsing engine implemented by parse.py. The parsing engine + accesses the instance variables directly. The class here does not + provide initialization of the tables; several subclasses exist to + do this (see the conv and pgen modules). + + The load() method reads the tables from a pickle file, which is + much faster than the other ways offered by subclasses. The pickle + file is written by calling dump() (after loading the grammar + tables using a subclass). The report() method prints a readable + representation of the tables to stdout, for debugging. + + The instance variables are as follows: + + symbol2number -- a dict mapping symbol names to numbers. Symbol + numbers are always 256 or higher, to distinguish + them from token numbers, which are between 0 and + 255 (inclusive). + + number2symbol -- a dict mapping numbers to symbol names; + these two are each other's inverse. + + states -- a list of DFAs, where each DFA is a list of + states, each state is a list of arcs, and each + arc is a (i, j) pair where i is a label and j is + a state number. The DFA number is the index into + this list. (This name is slightly confusing.) + Final states are represented by a special arc of + the form (0, j) where j is its own state number. + + dfas -- a dict mapping symbol numbers to (DFA, first) + pairs, where DFA is an item from the states list + above, and first is a set of tokens that can + begin this grammar rule (represented by a dict + whose values are always 1). + + labels -- a list of (x, y) pairs where x is either a token + number or a symbol number, and y is either None + or a string; the strings are keywords. The label + number is the index in this list; label numbers + are used to mark state transitions (arcs) in the + DFAs. + + start -- the number of the grammar's start symbol. + + keywords -- a dict mapping keyword strings to arc labels. + + tokens -- a dict mapping token numbers to arc labels. + + """ + + 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: Path) -> None: + """Dump the grammar tables to a pickle file.""" + + # 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 _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._update(d) + + def loads(self, pkl: bytes) -> None: + """Load the grammar tables from a pickle bytes object.""" + self._update(pickle.loads(pkl)) + + def copy(self: _P) -> _P: + """ + Copy the grammar. + """ + new = self.__class__() + 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) -> None: + """Dump the grammar tables to standard output, for debugging.""" + from pprint import pprint + + print("s2n") + pprint(self.symbol2number) + print("n2s") + pprint(self.number2symbol) + print("states") + pprint(self.states) + print("dfas") + pprint(self.dfas) + print("labels") + pprint(self.labels) + print("start", self.start) + + +# Map from operator to number (since tokenize doesn't do this) + +opmap_raw = """ +( LPAR +) RPAR +[ LSQB +] RSQB +: COLON +, COMMA +; SEMI ++ PLUS +- MINUS +* STAR +/ SLASH +| VBAR +& AMPER +< LESS +> GREATER += EQUAL +. DOT +% PERCENT +` BACKQUOTE +{ LBRACE +} RBRACE +@ AT +@= ATEQUAL +== EQEQUAL +!= NOTEQUAL +<> NOTEQUAL +<= LESSEQUAL +>= GREATEREQUAL +~ TILDE +^ CIRCUMFLEX +<< LEFTSHIFT +>> RIGHTSHIFT +** DOUBLESTAR ++= PLUSEQUAL +-= MINEQUAL +*= STAREQUAL +/= SLASHEQUAL +%= PERCENTEQUAL +&= AMPEREQUAL +|= VBAREQUAL +^= CIRCUMFLEXEQUAL +<<= LEFTSHIFTEQUAL +>>= RIGHTSHIFTEQUAL +**= DOUBLESTAREQUAL +// DOUBLESLASH +//= DOUBLESLASHEQUAL +-> RARROW +:= COLONEQUAL +""" + +opmap = {} +for line in opmap_raw.splitlines(): + if line: + op, name = line.split() + opmap[op] = getattr(token, name)