Fix grammar for type alias support (#3949)

Fixes #3948

diff --git a/CHANGES.md b/CHANGES.md
index 1f6a008d643cc6fe9159b7861147f10e85511a03..610a9de0e431af4bfff2a4fd39f2bfabeb31a4c9 100644 (file)
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -37,6 +37,9 @@
 
 <!-- Changes to the parser or to version autodetection -->
 
+- Add support for PEP 695 type aliases containing lambdas and other unusual expressions
+  (#3949)
+
 ### Performance
 
 <!-- Changes that improve Black's performance. -->

diff --git a/src/blib2to3/Grammar.txt b/src/blib2to3/Grammar.txt
index be91df757408cc226019898b47bb05bd6d5b2dcd..5db78723cecd4e4fdd474bb9a528448fc27ea4e4 100644 (file)
--- a/src/blib2to3/Grammar.txt
+++ b/src/blib2to3/Grammar.txt
@@ -108,7 +108,7 @@ dotted_as_names: dotted_as_name (',' dotted_as_name)*
 dotted_name: NAME ('.' NAME)*
 global_stmt: ('global' | 'nonlocal') NAME (',' NAME)*
 assert_stmt: 'assert' test [',' test]
-type_stmt: "type" NAME [typeparams] '=' expr
+type_stmt: "type" NAME [typeparams] '=' test
 
 compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated | async_stmt | match_stmt
 async_stmt: ASYNC (funcdef | with_stmt | for_stmt)

diff --git a/tests/data/cases/type_aliases.py b/tests/data/cases/type_aliases.py
index a3c1931c9fc08d63ca438a770dee65b64ce94249..9631bfd5ccc3c3cf815ab2421ac531f37810ff18 100644 (file)
--- a/tests/data/cases/type_aliases.py
+++ b/tests/data/cases/type_aliases.py
@@ -1,6 +1,10 @@
 # flags: --minimum-version=3.12
+
 type A=int
 type Gen[T]=list[T]
+type Alias[T]=lambda: T
+type And[T]=T and T
+type IfElse[T]=T if T else T
 
 type = aliased
 print(type(42))
@@ -9,6 +13,9 @@ print(type(42))
 
 type A = int
 type Gen[T] = list[T]
+type Alias[T] = lambda: T
+type And[T] = T and T
+type IfElse[T] = T if T else T
 
 type = aliased
 print(type(42))