parser: improve handling of vmap exprs to allow further comparisons

src/parser.rs

@@ -509,10 +509,11 @@ impl Parser {
                         self.consume(TokenKind::RightBrace, "Expected '}' to close vmap")?;
 
                         // Return a vmap expression with the previous expression as the mapping target
-                        return Ok(Expression::Vmap {
+                        expr = Expression::Vmap {
                             expr: Some(Box::new(expr)),
                             map,
-                        });
+                        };
+                        continue; // allow the outer `while` to detect ==, != … afterwards
                     }
                     break;
                 }