I've changed how string literals are handled in the script engine. Now the compiler evaluates them at compile time and stores a pointer to the application native string type in the byte code. This avoids the need to create new instances of strings every time a script uses a string literal, which in turn translates to a performance improvement.

A new asIStringFactory interface is used to perform the compile time evaluation. This also allows the application to keep track of the used string literals, and store them in a common pool to reduce memory consumption for duplicate string literals. With the factory interface there is also no need for the script engine to keep an internal copy of the string literals thus reducing memory consumption even further.

Since the byte code now stores the pointer to the actual string object, the byte code instruction asBC_STR has no use anymore, and with that the restriction of a 2^16 maximum amount of string literals is eliminated.

Besides the above benefits I should also be able to take this a step further as the compiler now knows that the life time of a string literal is guaranteed, so it should take advantage of that and avoid making unnecessary copies when passing string literals to functions, etc. Though this improvement has not yet been implemented.

For existing scripts there shouldn't be any changes, except if the application currently registers the string factory to return a non-const string object instance. As the string literals are now evaluated at compile time it is no longer possible to have them treated as non-const, still I've made it so that the compiler can when needed implicitly convert to a non-const instance by making a local copy of the string literal at run-time.

As the changes has been quite extensive, I decided to make it possible to temporarily turn off these changes until all bugs have been rooted out. To turn off the changes look for the #define AS_NEWSTRING in angelscript.h and comment out that line. Before I make the official release (hopefully before the end of the year) I'll remove this option completely.

Let me know if you encounter any problems with this, so I can have it corrected before the official release.

Regards,
Andreas

The only impact is that the asBC_STR instruction is no longer used. So far it is still defined so any JIT compiler that does something with that will not fail to compile. But I will eventually remove the definition all together, and then the JIT compilers will have to be updated to remove it as well.

I'm sorry, I missed your posts somehow. 

Can I assume you were able to resolve all your problems with the new string factory? 

The GetRawStringData is used when the script engine needs to know the original string content, for example when saving the bytecode. Currently it is also used during the compilation to make a copy of the string literals when finalizing the bytecode for a recently compiled script function. This is slightly unefficient and I'm looking into removing this, if I can find a better way. If I'm successful it will only be used when saving the bytecode. 

I'll make sure to include a clarification for these things in the documentation for the release.