1 files changed, 32 insertions, 0 deletions
diff --git a/dynarray.h b/dynarray.h
new file mode 100644
index 0000000..9ff1289
--- /dev/null
+++ b/dynarray.h
@@ -0,0 +1,32 @@
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+
+#define DEFINE_DYNARRAY(name, type) \
+  type *name; \
+  int name ## _len; \
+  int name ## _size;
+
+#define RESIZE_DYNARRAY(name, desired_len) { \
+  int orig_size = name ## _size; \
+  while(name ## _size < (desired_len)) \
+    name ## _size *= 2; \
+  /* don't bother shrinking for now.  when/if we do, we'll want to bake in \
+   * some kind of hysteresis so that we don't shrink until we've been under \
+   * for a while. */ \
+  if(name ## _size != orig_size) \
+    name = realloc(name, name ## _size * sizeof(*name)); \
+  name ## _len = desired_len; \
+}
+
+#define INIT_DYNARRAY(name, initial_len, initial_size) \
+  name ## _len = initial_len; \
+  name ## _size = initial_size; \
+  name = realloc(NULL, name ## _size * sizeof(*name))
+
+#define FREE_DYNARRAY(name) \
+  free(name);
+
+#define DYNARRAY_GET_TOP(name) \
+  (&name[name ## _len - 1])
+