1 files changed, 32 insertions, 0 deletions
diff --git a/stack.c b/stack.c
new file mode 100644
index 0000000..69ccb13
--- /dev/null
+++ b/stack.c
@@ -0,0 +1,32 @@
+#include <err.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "mem.h"
+#include "stack.h"
+
+void stack_alloc(struct stack *st)
+{
+	st->len = 0;
+	st->cap = 512;
+	st->items = MALLOC(sizeof(st->items[0]) * st->cap);
+}
+
+void *pop(struct stack *st)
+{
+	return st->items[--(st->len)];
+}
+
+void push(struct stack *st, void *item)
+{
+	if (st->len >= st->cap) {
+		st->cap <<= 1;
+		st->items = REALLOC(st->items, sizeof(st->items[0]) * st->cap);
+	}
+	st->items[st->len++] = item;
+}
+
+void stack_free(struct stack *st)
+{
+	free(st->items);
+}