Or, rather, the const_string function.
Simple thing, looks like:
STRING *foo = const_string(interpreter, c-style string constant);
Easy, right? Yeah. Easy.
Well, the real constant string is constructed like so:
STRING *foo = CONST_STRING(interpreter, "cstring");
These strings get folded into a constant table (interpreter->const_cstring_table). The drawback is that it needs a bit of work per file (include the .str file, adapt Makefile build rules).
See e.g. src/objects.c for usage patterns.
leo