implement some initial qbt backend stuff

1 files changed, 60 insertions, 0 deletions

diff --git a/src/vec.c b/src/vec.c
new file mode 100644
index 0000000..3f1aac6
--- /dev/null
+++ b/src/vec.c
@@ -0,0 +1,60 @@
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#include <ek/vec.h>
+
+struct vec vec_create(size_t ns)
+{
+	return (struct vec) {
+		       .n = 0,
+		       .s = 1,
+		       .ns = ns,
+		       .buf = malloc(ns),
+	};
+}
+
+size_t vec_len(struct vec *v)
+{
+	return v->n;
+}
+
+void *vec_at(struct vec *v, size_t i)
+{
+	assert(i < v->n && "out of vector bounds");
+	return v->buf + i * v->ns;
+}
+
+void *vec_back(struct vec *v)
+{
+	assert(v->n);
+	return v->buf + (v->n - 1) * v->ns;
+}
+
+void *vec_pop(struct vec *v)
+{
+	assert(v->n && "attempting to pop empty vector");
+	v->n--;
+	return v->buf + v->n * v->ns;
+}
+
+void vec_append(struct vec *v, void *n)
+{
+	v->n++;
+	if (v->n >= v->s) {
+		v->s *= 2;
+		v->buf = realloc(v->buf, v->s * v->ns);
+	}
+
+	void *p = vec_at(v, v->n - 1);
+	memcpy(p, n, v->ns);
+}
+
+void vec_reset(struct vec *v)
+{
+	v->n = 0;
+}
+
+void vec_destroy(struct vec *v) {
+	free(v->buf);
+}