Fix missing capturing of assignments

The previous commit was a bit overambitious. The left-hand side of assignments should actually be fully captured: Argument lists in `at` calls can contain captured variables. And if the assigned variable itself is captured, then the function is faulty anyway. (And we ensure the correct error message by capturing it.)

Fixes #2169

1 files changed, 0 insertions, 12 deletions

diff --git a/crates/typst-syntax/src/ast.rs b/crates/typst-syntax/src/ast.rs
index 0df3d6d3..cb1d05b2 100644
--- a/crates/typst-syntax/src/ast.rs
+++ b/crates/typst-syntax/src/ast.rs
@@ -1440,18 +1440,6 @@ impl BinOp {
         })
     }
 
-    /// Whether this is an assignment operator.
-    pub fn is_assignment(self) -> bool {
-        matches!(
-            self,
-            Self::Assign
-                | Self::AddAssign
-                | Self::SubAssign
-                | Self::MulAssign
-                | Self::DivAssign
-        )
-    }
-
     /// The precedence of this operator.
     pub fn precedence(self) -> usize {
         match self {