Use interpolated_or_expr_span in one suitable place.

Author: nnethercote

compiler/rustc_parse/src/parser/expr.rs

@@ -193,13 +193,7 @@ impl<'a> Parser<'a> {
 
         self.expected_tokens.push(TokenType::Operator);
         while let Some(op) = self.check_assoc_op() {
-            // Adjust the span for interpolated LHS to point to the `$lhs` token
-            // and not to what it refers to.
-            let lhs_span = match self.prev_token.kind {
-                TokenKind::Interpolated(..) => self.prev_token.span,
-                _ => lhs.span,
-            };
-
+            let lhs_span = self.interpolated_or_expr_span(&lhs);
             let cur_op_span = self.token.span;
             let restrictions = if op.node.is_assign_like() {
                 self.restrictions & Restrictions::NO_STRUCT_LITERAL
@@ -702,7 +696,8 @@ impl<'a> Parser<'a> {
         self.parse_expr_unary(lo, UnOp::Not)
     }
 
-    /// Returns the span of expr, if it was not interpolated or the span of the interpolated token.
+    /// Returns the span of `expr` if it was not interpolated, or the span of the interpolated
+    /// token.
     fn interpolated_or_expr_span(&self, expr: &Expr) -> Span {
         match self.prev_token.kind {
             TokenKind::Interpolated(..) => self.prev_token.span,