-void ds_putchar (struct string *, int ch);
-void ds_concat (struct string *, const char *);
-void ds_concat_buffer (struct string *, const char *buf, size_t len);
-void ds_vprintf (struct string *st, const char *format, va_list args);
+
+/* Append. */
+void ds_putc (struct string *, int ch);
+void ds_puts (struct string *, const char *);
+void ds_concat (struct string *, const char *, size_t);
+void ds_vprintf (struct string *st, const char *, va_list);