f

src/compiler.h

@@ -74,8 +74,6 @@ public:
         rules[TK("@str")] =     { METHOD(exprLiteral),   NO_INFIX };
         rules[TK("@fstr")] =    { METHOD(exprFString),   NO_INFIX };
         rules[TK("?")] =        { nullptr,               METHOD(exprTernary),        PREC_TERNARY };
-        // do not include standalone, as it allows naked assignment
-        //rules[TK(":=")] =        { nullptr,               METHOD(exprWalrus),         PREC_ASSIGNMENT };
         rules[TK("=")] =        { nullptr,               METHOD(exprAssign),         PREC_ASSIGNMENT };
         rules[TK("+=")] =       { nullptr,               METHOD(exprAssign),         PREC_ASSIGNMENT };
         rules[TK("-=")] =       { nullptr,               METHOD(exprAssign),         PREC_ASSIGNMENT };
@@ -402,13 +400,6 @@ private:
         emit(OP_LOAD_LAMBDA, co()->add_const(vm->PyFunction(func)));
     }
 
-    void exprWalrus() {
-        // NAME is on stack
-        EXPR_TUPLE();
-        // EXPR is on stack
-        emit(OP_STORE_REF); // will pop the value and the name off the stack,
-        // we need to return the value now
-    }
     void exprAssign() {
         co()->_rvalue = true;
         TokenIndex op = parser->prev.type;
@@ -512,21 +503,10 @@ private:
     }
 
     void exprGrouping() {
-        //  either a expr in parens,
-        // or a tuple.
         match_newlines(mode()==REPL_MODE);
-        // do {
-        //     if (peek() == TK("@id")) {
-        //         consume(TK("@id"));
-        //         exprAssign();
-        //     }
-        //     else {
-        //         EXPR();
-        //     }
-        // } while (match(TK(",")));
-    //    EXPR_TUPLE();
         do {
             if (peek() == TK(")")) break;
+            // match walrus operator
             if(peek() == TK("@id") && peek_next() == TK(":=")) {
                 consume(TK("@id"));
                 Token tkname = parser->prev;
@@ -534,26 +514,18 @@ private:
                     tkname.str(),
                     codes.size()>1 ? NAME_LOCAL : NAME_GLOBAL
                 );
+                // store the expr into NAME,
+                // and push it on the stack as well,
+                // so it is available as a value
+                // in the expression
                 emit(OP_LOAD_NAME_REF, index);
                 consume(TK(":="));
-                exprWalrus();
+                EXPR();
+                emit(OP_STORE_REF);
                 emit(OP_LOAD_NAME, index);
-
-                // const Str& key = parser->prev.str();
-                // emit(OP_LOAD_CONST, co()->add_const(vm->PyStr(key)));
-                // consume(TK("="));
-                // co()->_rvalue=true; EXPR(); co()->_rvalue=false;
-            }
-            else {
-                EXPR_TUPLE();
             }
+            else  EXPR_TUPLE();
         } while (match(TK(",")));
-        // if (peek() == TK("@id")) {
-        //     consume(TK("@id"));
-        //     exprAssign();
-        // } else {
-        //     EXPR_TUPLE();
-        // }
         match_newlines(mode()==REPL_MODE);
         consume(TK(")"));
     }

tests/_basic.py

@@ -4,7 +4,7 @@ assert 0xffff == 65535
 assert 0xAAFFFF == 11206655
 assert 0x7fffffff == 2147483647
 
-# test == != >= <= < > 
+# test == != >= <= < >
 # generate 2 cases for each operator
 assert -1 == -1
 assert -1 != 1
@@ -99,7 +99,7 @@ assert [1, 2, 3] == [1, 2, 3]
 assert [1, 2, 3] != [1, 2, 4]
 
 # test + *=
-assert [1, 2, 3] + [4, 5, 6] == [1, 2, 3, 4, 5, 6]          
+assert [1, 2, 3] + [4, 5, 6] == [1, 2, 3, 4, 5, 6]
 assert [1, 2, 3] * 3 == [1, 2, 3, 1, 2, 3, 1, 2, 3]
 
 # test ?:
@@ -117,3 +117,13 @@ assert round(23.2) == 23
 assert round(23.8) == 24
 assert round(-23.2) == -23
 assert round(-23.8) == -24
+
+assert (x := 1) == 1
+assert (a := 1, b := 2)
+assert a == 1
+assert b == 2
+
+assert (x := (a := 1, b := 2)) == (1, 2)
+assert x == 1
+assert (x := 0) + 1 == 1
+assert (x := 1, y := 2, 3) == (1,2,3)

tests/_controlflow.py

@@ -1,16 +1,16 @@
 # if tests
 flag = False
 name = 'luren'
-if name == 'python':         
-    flag = True              
+if name == 'python':
+    flag = True
 else:
-    flag               
+    flag
 assert flag == False
 
 
 num = 9
 flag = 0
-if num >= 0 and num <= 10:    
+if num >= 0 and num <= 10:
     flag = 1
 else:
     flag
@@ -18,27 +18,27 @@ assert flag == 1
 
 num = 10
 flag = 0
-if num < 0 or num > 10:    
+if num < 0 or num > 10:
     flag = 1
 else:
     flag
 assert flag == 0
 
 num = 5
-result = 0     
-if num == 3:            
-    result = num        
+result = 0
+if num == 3:
+    result = num
 elif num == 2:
     result = num
 elif num == 1:
     result = num
-elif num < 0:           
+elif num < 0:
     result = num
 else:
     result = num
-assert result == 5    
+assert result == 5
 
-# for tests 
+# for tests
 
 k = 0
 for i in range(2, 1000):
@@ -64,4 +64,3 @@ count = 0
 while (count < 1000):
    count = count + 1
 assert count == 1000
-

tests/_walrus.py

@@ -1,7 +0,0 @@
-assert ( x := 1) == 1
-assert ( y := 1) + 2 == 3
-
-a = (y := 4) + 5
-assert a == 9
-assert y == 4
-