Improve read.c

src/memory.c

@@ -50,6 +50,11 @@ static void ensure_string_stream_space(StringStream *restrict stream,
     }
 }
 
+void string_stream_putc(StringStream *restrict stream, char c) {
+    ensure_string_stream_space(stream, 1);
+    stream->buffer[stream->nchars++] = c;
+}
+
 int string_stream_printf(StringStream *restrict stream,
                          const char *restrict format, ...) {
     va_list args;