patch 9.0.2027: Vim9: no support for bitwise operators in lambda funcs

Problem:  Vim9: no support for bitwise operators in lambda funcs
Solution: move "evaluate" assignment a bit up in order to decide
          to perform bitwise operations

closes: #13342
closes: #13345

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Yegappan Lakshmanan <yegappan@yahoo.com>

src/eval.c

@@ -3515,7 +3515,8 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	    return OK;
 
 	// Handle a bitwise left or right shift operator
-	if (rettv->v_type != VAR_NUMBER)
+	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
+	if (evaluate && rettv->v_type != VAR_NUMBER)
 	{
 	    // left operand should be a number
 	    emsg(_(e_bitshift_ops_must_be_number));
@@ -3523,7 +3524,6 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	    return FAIL;
 	}
 
-	evaluate = evalarg == NULL ? 0 : (evalarg->eval_flags & EVAL_EVALUATE);
 	vim9script = in_vim9script();
 	if (getnext)
 	{
@@ -3553,6 +3553,8 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 	    return FAIL;
 	}
 
+	if (evaluate)
+	{
 	    if (var2.v_type != VAR_NUMBER || var2.vval.v_number < 0)
 	    {
 		// right operand should be a positive number
@@ -3565,8 +3567,6 @@ eval5(char_u **arg, typval_T *rettv, evalarg_T *evalarg)
 		return FAIL;
 	    }
 
-	if (evaluate)
-	{
 	    if (var2.vval.v_number > MAX_LSHIFT_BITS)
 		// shifting more bits than we have always results in zero
 		rettv->vval.v_number = 0;

src/testdir/test_expr.vim

@@ -1041,6 +1041,50 @@ func Test_bitwise_shift()
      assert_equal(16, a)
   END
   call v9.CheckDefAndScriptSuccess(lines)
+
+  let lines =<< trim END
+    # Use in a lambda function
+    const DivBy2Ref_A = (n: number): number => n >> 1
+    assert_equal(16, DivBy2Ref_A(32))
+    const DivBy2Ref_B = (n: number): number => (<number>n) >> 1
+    assert_equal(16, DivBy2Ref_B(32))
+    const MultBy2Ref_A = (n: number): number => n << 1
+    assert_equal(8, MultBy2Ref_A(4))
+    const MultBy2Ref_B = (n: number): number => (<number>n) << 1
+    assert_equal(8, MultBy2Ref_B(4))
+
+    def DivBy2_A(): func(number): number
+      return (n: number): number => n >> 1
+    enddef
+    assert_equal(16, DivBy2_A()(32))
+    def DivBy2_B(): func(number): number
+      return (n: number): number => (<number>n) >> 1
+    enddef
+    assert_equal(16, DivBy2_B()(32))
+    def MultBy2_A(): func(number): number
+      return (n: number): number => n << 1
+    enddef
+    assert_equal(64, MultBy2_A()(32))
+    def MultBy2_B(): func(number): number
+      return (n: number): number => (<number>n) << 1
+    enddef
+    assert_equal(64, MultBy2_B()(32))
+  END
+  call v9.CheckDefAndScriptSuccess(lines)
+
+  " Use in a legacy lambda function
+  const DivBy2Ref_A = {n -> n >> 1}
+  call assert_equal(16, DivBy2Ref_A(32))
+  func DivBy2_A()
+    return {n -> n >> 1}
+  endfunc
+  call assert_equal(16, DivBy2_A()(32))
+  const MultBy2Ref_A = {n -> n << 1}
+  call assert_equal(64, MultBy2Ref_A(32))
+  func MultBy2_A()
+    return {n -> n << 1}
+  endfunc
+  call assert_equal(64, MultBy2_A()(32))
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2027,
 /**/
     2026,
 /**/