fn walkFor(w: *Walk, for_node: Ast.full.For) Error!void
fn walkFor(w: *Walk, for_node: Ast.full.For) Error!void { try walkExpressions(w, for_node.ast.inputs); try walkExpression(w, for_node.ast.then_expr); if (for_node.ast.else_expr.unwrap()) |else_expr| { try walkExpression(w, else_expr); } }