Speed up new backtracking parser (#2728)

[etc/vim.git] / src / black / mode.py

diff --git a/src/black/mode.py b/src/black/mode.py
index e2417531240b7c38ae0a61d782a84f9cdf9ee7fd..5e04525cfc989a5619255e4119581c7c263761d0 100644 (file)
--- a/src/black/mode.py
+++ b/src/black/mode.py
@@ -4,16 +4,22 @@ Mostly around Python language feature support per version and Black configuratio
 chosen by the user.
 """
 
+import sys
+
 from dataclasses import dataclass, field
 from enum import Enum
 from operator import attrgetter
 from typing import Dict, Set
 
+if sys.version_info < (3, 8):
+    from typing_extensions import Final
+else:
+    from typing import Final
+
 from black.const import DEFAULT_LINE_LENGTH
 
 
 class TargetVersion(Enum):
-    PY27 = 2
     PY33 = 3
     PY34 = 4
     PY35 = 5
@@ -23,13 +29,8 @@ class TargetVersion(Enum):
     PY39 = 9
     PY310 = 10
 
-    def is_python2(self) -> bool:
-        return self is TargetVersion.PY27
-
 
 class Feature(Enum):
-    # All string literals are unicode
-    UNICODE_LITERALS = 1
     F_STRINGS = 2
     NUMERIC_UNDERSCORES = 3
     TRAILING_COMMA_IN_CALL = 4
@@ -42,40 +43,24 @@ class Feature(Enum):
     POS_ONLY_ARGUMENTS = 9
     RELAXED_DECORATORS = 10
     PATTERN_MATCHING = 11
+    UNPACKING_ON_FLOW = 12
+    ANN_ASSIGN_EXTENDED_RHS = 13
     FORCE_OPTIONAL_PARENTHESES = 50
 
-    # temporary for Python 2 deprecation
-    PRINT_STMT = 200
-    EXEC_STMT = 201
-    AUTOMATIC_PARAMETER_UNPACKING = 202
-    COMMA_STYLE_EXCEPT = 203
-    COMMA_STYLE_RAISE = 204
-    LONG_INT_LITERAL = 205
-    OCTAL_INT_LITERAL = 206
-    BACKQUOTE_REPR = 207
+    # __future__ flags
+    FUTURE_ANNOTATIONS = 51
+
+
+FUTURE_FLAG_TO_FEATURE: Final = {
+    "annotations": Feature.FUTURE_ANNOTATIONS,
+}
 
 
 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
-    TargetVersion.PY27: {
-        Feature.ASYNC_IDENTIFIERS,
-        Feature.PRINT_STMT,
-        Feature.EXEC_STMT,
-        Feature.AUTOMATIC_PARAMETER_UNPACKING,
-        Feature.COMMA_STYLE_EXCEPT,
-        Feature.COMMA_STYLE_RAISE,
-        Feature.LONG_INT_LITERAL,
-        Feature.OCTAL_INT_LITERAL,
-        Feature.BACKQUOTE_REPR,
-    },
-    TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
-    TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
-    TargetVersion.PY35: {
-        Feature.UNICODE_LITERALS,
-        Feature.TRAILING_COMMA_IN_CALL,
-        Feature.ASYNC_IDENTIFIERS,
-    },
+    TargetVersion.PY33: {Feature.ASYNC_IDENTIFIERS},
+    TargetVersion.PY34: {Feature.ASYNC_IDENTIFIERS},
+    TargetVersion.PY35: {Feature.TRAILING_COMMA_IN_CALL, Feature.ASYNC_IDENTIFIERS},
     TargetVersion.PY36: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
@@ -83,44 +68,50 @@ VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
         Feature.ASYNC_IDENTIFIERS,
     },
     TargetVersion.PY37: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
         Feature.ASYNC_KEYWORDS,
+        Feature.FUTURE_ANNOTATIONS,
     },
     TargetVersion.PY38: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
         Feature.ASYNC_KEYWORDS,
+        Feature.FUTURE_ANNOTATIONS,
         Feature.ASSIGNMENT_EXPRESSIONS,
         Feature.POS_ONLY_ARGUMENTS,
+        Feature.UNPACKING_ON_FLOW,
+        Feature.ANN_ASSIGN_EXTENDED_RHS,
     },
     TargetVersion.PY39: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
         Feature.ASYNC_KEYWORDS,
+        Feature.FUTURE_ANNOTATIONS,
         Feature.ASSIGNMENT_EXPRESSIONS,
         Feature.RELAXED_DECORATORS,
         Feature.POS_ONLY_ARGUMENTS,
+        Feature.UNPACKING_ON_FLOW,
+        Feature.ANN_ASSIGN_EXTENDED_RHS,
     },
     TargetVersion.PY310: {
-        Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
         Feature.ASYNC_KEYWORDS,
+        Feature.FUTURE_ANNOTATIONS,
         Feature.ASSIGNMENT_EXPRESSIONS,
         Feature.RELAXED_DECORATORS,
         Feature.POS_ONLY_ARGUMENTS,
+        Feature.UNPACKING_ON_FLOW,
+        Feature.ANN_ASSIGN_EXTENDED_RHS,
         Feature.PATTERN_MATCHING,
     },
 }