1 files changed, 19 insertions, 0 deletions
diff --git a/lib/arena_strings.h b/lib/arena_strings.h
index 85ffda3..b25435d 100644
--- a/lib/arena_strings.h
+++ b/lib/arena_strings.h
@@ -10,8 +10,27 @@ typedef struct {
   size_t cap;
 } const_string_da;
 
+typedef struct {
+  char* data;
+  size_t len;
+  size_t cap;
+} string_builder;
+
 const_string arena_cs_append(arena *a, const_string dst, const_string src);
 const_string arena_cs_init(arena *a, int len);
 const_string arena_cs_concat(arena *a, const_string_da strings, const_string sep);
 
+#define arena_sb_append_buf(a, sb, buf, len) arena_da_append_many((a), (sb), (buf), (len))
+
+#define arena_sb_append_cstr(a, sb, cstr)				\
+    do {												\
+        const char * str = (cstr);						\
+        size_t len = strlen((cstr));					\
+        arena_da_append_many((a), (sb), (str), len);	\
+    } while (0)
+
+#define arena_sb_append_null(a, sb)	arena_da_append_many((a), (sb), "", 1)
+
+#define arena_sb_to_cs(sb) cs_from_parts((sb).data, (sb).len)
+
 #endif // ARENA_STRINGS_H_