Allow walrus in slices

zsol · zsol · commit 110109aee674 · 2023-05-27T10:07:19.000+01:00
See python/cpython#23317 Raised in #930.
diff --git a/native/libcst/src/parser/grammar.rs b/native/libcst/src/parser/grammar.rs
@@ -1004,7 +1004,7 @@ parser! {
                     make_slice(l, col, u, rest)
             }
             / e:starred_expression() { make_index_from_arg(e) }
-            / v:expression() { make_index(v) }
+            / v:named_expression() { make_index(v) }
 
         rule atom() -> Expression<'input, 'a>
             = n:name() { Expression::Name(Box::new(n)) }
diff --git a/native/libcst/tests/fixtures/wonky_walrus.py b/native/libcst/tests/fixtures/wonky_walrus.py
@@ -10,4 +10,6 @@
 if f := x(): pass
 
 f(y:=1)
-f(x,  y   :=    1     )
+f(x,  y   :=    1     )
+
+_[_:=10]

Original file line number	Diff line number	Diff line change
`@@ -1004,7 +1004,7 @@ parser! {`
`1004`	`1004`	`make_slice(l, col, u, rest)`
`1005`	`1005`	`}`
`1006`	`1006`	`/ e:starred_expression() { make_index_from_arg(e) }`
`1007`		`- / v:expression() { make_index(v) }`
	`1007`	`+ / v:named_expression() { make_index(v) }`
`1008`	`1008`
`1009`	`1009`	`rule atom() -> Expression<'input, 'a>`
`1010`	`1010`	`= n:name() { Expression::Name(Box::new(n)) }`