]> git.madduck.net Git - etc/vim.git/blobdiff - src/blib2to3/pgen2/parse.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Don't let TokenError bubble up from lib2to3_parse (GH-2343)
[etc/vim.git] / src / blib2to3 / pgen2 / parse.py
index dc405264bad454a92469cb613b6dd962c394e837..792e8e66698246f578fef7ce88d7bf69258af3e9 100644 (file)
@@ -29,7 +29,7 @@ from typing import (
     TYPE_CHECKING,
 )
 from blib2to3.pgen2.grammar import Grammar
-from blib2to3.pytree import NL, Context, RawNode, Leaf, Node
+from blib2to3.pytree import convert, NL, Context, RawNode, Leaf, Node
 
 if TYPE_CHECKING:
     from blib2to3.driver import TokenProxy
@@ -70,9 +70,7 @@ class Recorder:
         finally:
             self.parser.stack = self._start_point
 
-    def add_token(
-        self, tok_type: int, tok_val: Optional[Text], raw: bool = False
-    ) -> None:
+    def add_token(self, tok_type: int, tok_val: Text, raw: bool = False) -> None:
         func: Callable[..., Any]
         if raw:
             func = self.parser._addtoken
@@ -86,9 +84,7 @@ class Recorder:
                     args.insert(0, ilabel)
                 func(*args)
 
-    def determine_route(
-        self, value: Optional[Text] = None, force: bool = False
-    ) -> Optional[int]:
+    def determine_route(self, value: Text = None, force: bool = False) -> Optional[int]:
         alive_ilabels = self.ilabels
         if len(alive_ilabels) == 0:
             *_, most_successful_ilabel = self._dead_ilabels
@@ -164,6 +160,11 @@ class Parser(object):
         to be converted.  The syntax tree is converted from the bottom
         up.
 
+        **post-note: the convert argument is ignored since for Black's
+        usage, convert will always be blib2to3.pytree.convert. Allowing
+        this to be dynamic hurts mypyc's ability to use early binding.
+        These docs are left for historical and informational value.
+
         A concrete syntax tree node is a (type, value, context, nodes)
         tuple, where type is the node type (a token or symbol number),
         value is None for symbols and a string for tokens, context is
@@ -176,6 +177,7 @@ class Parser(object):
 
         """
         self.grammar = grammar
+        # See note in docstring above. TL;DR this is ignored.
         self.convert = convert or lam_sub
 
     def setup(self, proxy: "TokenProxy", start: Optional[int] = None) -> None:
@@ -203,7 +205,7 @@ class Parser(object):
         self.used_names: Set[str] = set()
         self.proxy = proxy
 
-    def addtoken(self, type: int, value: Optional[Text], context: Context) -> bool:
+    def addtoken(self, type: int, value: Text, context: Context) -> bool:
         """Add a token; return True iff this is the end of the program."""
         # Map from token to label
         ilabels = self.classify(type, value, context)
@@ -237,7 +239,7 @@ class Parser(object):
 
                 next_token_type, next_token_value, *_ = proxy.eat(counter)
                 if next_token_type == tokenize.OP:
-                    next_token_type = grammar.opmap[cast(str, next_token_value)]
+                    next_token_type = grammar.opmap[next_token_value]
 
                 recorder.add_token(next_token_type, next_token_value)
                 counter += 1
@@ -247,9 +249,7 @@ class Parser(object):
 
         return self._addtoken(ilabel, type, value, context)
 
-    def _addtoken(
-        self, ilabel: int, type: int, value: Optional[Text], context: Context
-    ) -> bool:
+    def _addtoken(self, ilabel: int, type: int, value: Text, context: Context) -> bool:
         # Loop until the token is shifted; may raise exceptions
         while True:
             dfa, state, node = self.stack[-1]
@@ -257,10 +257,18 @@ class Parser(object):
             arcs = states[state]
             # Look for a state with this label
             for i, newstate in arcs:
-                t, v = self.grammar.labels[i]
-                if ilabel == i:
+                t = self.grammar.labels[i][0]
+                if t >= 256:
+                    # See if it's a symbol and if we're in its first set
+                    itsdfa = self.grammar.dfas[t]
+                    itsstates, itsfirst = itsdfa
+                    if ilabel in itsfirst:
+                        # Push a symbol
+                        self.push(t, itsdfa, newstate, context)
+                        break  # To continue the outer while loop
+
+                elif ilabel == i:
                     # Look it up in the list of labels
-                    assert t < 256
                     # Shift a token; we're done with it
                     self.shift(type, value, newstate, context)
                     # Pop while we are in an accept-only state
@@ -274,14 +282,7 @@ class Parser(object):
                         states, first = dfa
                     # Done with this token
                     return False
-                elif t >= 256:
-                    # See if it's a symbol and if we're in its first set
-                    itsdfa = self.grammar.dfas[t]
-                    itsstates, itsfirst = itsdfa
-                    if ilabel in itsfirst:
-                        # Push a symbol
-                        self.push(t, self.grammar.dfas[t], newstate, context)
-                        break  # To continue the outer while loop
+
             else:
                 if (0, state) in arcs:
                     # An accepting state, pop it and try something else
@@ -293,14 +294,13 @@ class Parser(object):
                     # No success finding a transition
                     raise ParseError("bad input", type, value, context)
 
-    def classify(self, type: int, value: Optional[Text], context: Context) -> List[int]:
+    def classify(self, type: int, value: Text, context: Context) -> List[int]:
         """Turn a token into a label.  (Internal)
 
         Depending on whether the value is a soft-keyword or not,
         this function may return multiple labels to choose from."""
         if type == token.NAME:
             # Keep a listing of all used names
-            assert value is not None
             self.used_names.add(value)
             # Check for reserved words
             if value in self.grammar.keywords:
@@ -317,18 +317,13 @@ class Parser(object):
             raise ParseError("bad token", type, value, context)
         return [ilabel]
 
-    def shift(
-        self, type: int, value: Optional[Text], newstate: int, context: Context
-    ) -> None:
+    def shift(self, type: int, value: Text, newstate: int, context: Context) -> None:
         """Shift a token.  (Internal)"""
         dfa, state, node = self.stack[-1]
-        assert value is not None
-        assert context is not None
         rawnode: RawNode = (type, value, context, None)
-        newnode = self.convert(self.grammar, rawnode)
-        if newnode is not None:
-            assert node[-1] is not None
-            node[-1].append(newnode)
+        newnode = convert(self.grammar, rawnode)
+        assert node[-1] is not None
+        node[-1].append(newnode)
         self.stack[-1] = (dfa, newstate, node)
 
     def push(self, type: int, newdfa: DFAS, newstate: int, context: Context) -> None:
@@ -341,12 +336,11 @@ class Parser(object):
     def pop(self) -> None:
         """Pop a nonterminal.  (Internal)"""
         popdfa, popstate, popnode = self.stack.pop()
-        newnode = self.convert(self.grammar, popnode)
-        if newnode is not None:
-            if self.stack:
-                dfa, state, node = self.stack[-1]
-                assert node[-1] is not None
-                node[-1].append(newnode)
-            else:
-                self.rootnode = newnode
-                self.rootnode.used_names = self.used_names
+        newnode = convert(self.grammar, popnode)
+        if self.stack:
+            dfa, state, node = self.stack[-1]
+            assert node[-1] is not None
+            node[-1].append(newnode)
+        else:
+            self.rootnode = newnode
+            self.rootnode.used_names = self.used_names