added sum types

src/lib/objects/o_sum.c

@@ -0,0 +1,66 @@
+#include "../common/defs.h" 
+#include "objects.h"
+
+static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp);
+static bool istypeof(Object *self, Object *other, Heap *heap, Error *error);
+
+typedef struct {
+    Object  base;
+    Object *items[2];
+} SumObject;
+
+static TypeObject t_sum = {
+    .base = (Object) { .type = &t_type, .flags = Object_STATIC },
+    .name = TYPENAME_SUM,
+    .size = sizeof(SumObject),
+    .init = NULL,
+    .free = NULL,
+    .hash = NULL,
+    .copy = NULL,
+    .call = NULL,
+    .print = NULL,
+
+    .select = NULL,
+    .delete = NULL,
+    .insert = NULL,
+    .count  = NULL,
+
+    .istypeof = istypeof,
+
+    .op_eql = NULL,
+    .walk = walk,
+    .walkexts = NULL,
+};
+
+TypeObject *Object_GetSumType()
+{
+    return &t_sum;
+}
+
+Object *Object_NewSum(Object *item0, Object *item1, Heap *heap, Error *error)
+{
+    SumObject *sum = (SumObject*) Heap_Malloc(heap, &t_sum, error);
+    if (sum != NULL) {
+        sum->items[0] = item0;
+        sum->items[1] = item1;
+    }
+    return (Object*) sum;
+}
+
+static bool 
+istypeof(Object *self, 
+         Object *other, 
+         Heap   *heap, 
+         Error  *error)
+{
+    SumObject *sum = (SumObject*) self;
+    return Object_IsTypeOf(sum->items[0], other, heap, error)
+        || Object_IsTypeOf(sum->items[1], other, heap, error);
+}
+
+static void walk(Object *self, void (*callback)(Object **referer, void *userp), void *userp)
+{
+    SumObject *sum = (SumObject*) self;
+    callback(sum->items + 0, userp);
+    callback(sum->items + 1, userp);
+}