FEAT: implemented odd? and even? on pair!

resolves: Oldes/Rebol-issues#1884

Author: Oldes

src/core/t-pair.c

@@ -181,6 +181,7 @@
 	REBINT n = 0;
 	REBD32 x1, x2 = 0.0;
 	REBD32 y1, y2 = 0.0;
+	REBINT x, y;
 
 	val = D_ARG(1);
 	x1 = VAL_PAIR_X(val);
@@ -239,13 +240,6 @@
 	else {
 		switch(action) {
 
-#ifdef temp
-		case A_ODDQ:
-			DECIDE((x1 & 1) && (y1 & 1));
-
-		case A_EVENQ:
-			DECIDE((x1 & 1) == 0 && (y1 & 1) == 0);
-#endif
 		case A_NEGATE:
 			x1 = -x1;
 			y1 = -y1;
@@ -345,6 +339,16 @@
 					return R_RET;
 			}
 			Trap_Make(REB_PAIR, val);
+
+		case A_ODDQ:
+		case A_EVENQ:
+			x = VAL_PAIR_X_INT(val) & 1;
+			y = VAL_PAIR_Y_INT(val) & 1;
+			if (action == A_ODDQ)
+				DECIDE(x && y);
+			else	
+				DECIDE(x == 0 && y == 0);
+
 		}
 	}
 	Trap_Action(REB_PAIR, action);
@@ -355,10 +359,10 @@
 	VAL_PAIR_Y(DS_RETURN) = y1;
 	return R_RET;
 
-//is_false:
-//	return R_FALSE;
+is_false:
+	return R_FALSE;
 
-//is_true:
-//	return R_TRUE;
+is_true:
+	return R_TRUE;
 }
 

src/tests/units/pair-test.r3

@@ -238,6 +238,28 @@ Rebol [
 
 ===end-group===
 
+===start-group=== "pair - even?/odd?"
+	;@@ https://github.com/Oldes/Rebol-issues/issues/1884
+	--test-- "odd?"
+		--assert not odd? 0x0
+		--assert not odd? 0x1
+		--assert not odd? 1x0
+		--assert     odd? 1x1
+		--assert not odd? 2x2
+		--assert     odd? 1.1x2.9
+		--assert not odd? 1.1x2.2
+		
+	--test-- "even?"
+		--assert     even? 0x0
+		--assert not even? 0x1
+		--assert not even? 1x0
+		--assert not even? 1x1
+		--assert     even? 2x2
+		--assert     even? 1.9x2.1
+		--assert not even? 1.1x2.2
+
+===end-group===
+
 ===start-group=== "pair - issues"
 
 	--test-- "invalid construction"