fix a bug

src/compiler.h

@@ -301,6 +301,9 @@ class Compiler {
         EXPR_TUPLE();   // () is just for change precedence
         match_newlines_repl();
         consume(TK(")"));
+        if(ctx()->s_expr.top()->is_tuple()) return;
+        Expr_ g = make_expr<GroupedExpr>(ctx()->s_expr.popx());
+        ctx()->s_expr.push(std::move(g));
     }
 
     template<typename T>

src/expr.h

@@ -24,6 +24,7 @@ struct Expr{
     virtual bool is_attrib() const { return false; }
     virtual bool is_compare() const { return false; }
     virtual int star_level() const { return 0; }
+    virtual bool is_tuple() const { return false; }
     bool is_starred() const { return star_level() > 0; }
 
     // for OP_DELETE_XXX
@@ -445,6 +446,7 @@ struct SetExpr: SequenceExpr{
 struct TupleExpr: SequenceExpr{
     using SequenceExpr::SequenceExpr;
     std::string str() const override { return "Tuple()"; }
+    bool is_tuple() const override { return true; }
     Opcode opcode() const override {
         for(auto& e: items) if(e->is_starred()) return OP_BUILD_TUPLE_UNPACK;
         return OP_BUILD_TUPLE;
@@ -734,6 +736,17 @@ struct CallExpr: Expr{
     }
 };
 
+struct GroupedExpr: Expr{
+    Expr_ a;
+    std::string str() const override { return "Grouped()"; }
+
+    GroupedExpr(Expr_&& a): a(std::move(a)) {}
+
+    void emit(CodeEmitContext* ctx) override{
+        a->emit(ctx);
+    }
+};
+
 struct BinaryExpr: Expr{
     TokenIndex op;
     Expr_ lhs;

tests/31_cmp.py

@@ -13,4 +13,7 @@ assert 1<1+1<3<2+2<5
 a = [1,2,3]
 assert a[0] < a[1] < a[2]
 assert a[0]+1 == a[1] < a[2]
-assert a[0]+1 == a[1] < a[2]+1 < 5
+assert a[0]+1 == a[1] < a[2]+1 < 5
+
+assert (4>3<2) == False
+# assert ((4>3)<2) == True