vlist.c

implementations/C/vlist.c

@@ -0,0 +1,49 @@
+#include <gc.h>
+#include "joy.h"
+
+
+typedef struct vlist {
+	struct vlist *base;
+	int offset, size, last_used;
+	JoyTypePtr *data;
+} VList;
+
+typedef struct {
+	VList *base;
+	int offset;
+} VListNode;
+
+
+VListNode *
+vlist_cons(JoyTypePtr thing, VListNode *vlnode)
+{
+	VListNode *result = GC_malloc(sizeof(VListNode));
+	if (!vlnode) {
+		result->base = GC_malloc(sizeof(VList));
+		result->offset = 0;
+		result->base->base = NULL;
+		result->base->offset = 0;
+		result->base->size = 1;
+		result->base->last_used = 1;
+		result->base->data[0] = thing;
+		return result;
+	}
+	if (vlnode->offset == vlnode->base->last_used - 1 && vlnode->base->last_used < vlnode->base->size) {
+		result->base = vlnode->base;
+		result->offset = vlnode->offset + 1;
+		vlnode->base->data[result->offset] = thing;
+		vlnode->base->last_used += 1;
+		return result;
+	}
+	result->base = GC_malloc(sizeof(VList));
+	result->offset = 0;
+	result->base->base = vlnode->base;
+	result->base->offset = 0;
+	result->base->size = vlnode->base->size << 1;
+	result->base->last_used = 1;
+	result->base->data = GC_malloc(result->base->size * sizeof(JoyTypePtr));
+	result->base->data[0] = thing;
+	return result;
+}
+
+