v3 for you, v3 for me!

To make a new vergec function:

Step 1.

You must create a C function to actually implement your new vc function’s logic. The naming convention is vc_NAMEofYOURnewFUNCTION, and convention says to put it in vc_builtins.cpp. If you’re returning a string, you will want to alter the std::string variable vc->vcretstr within your new function. If you’re returning an int, you’ll want to alter the integer vc->vcreturn instead.

Step 2.

You must add a function call to the array of libfuncs, also in vc_builtins.cpp. This is an ordered list of droupings of 3 c-style strings apiece. Each grouping represents a vc function: The first is the return signature, the second is the name, the third is the argument signature.

Here is an example line: {“3″, “DictListKeys”, “13″},

The “3″ for the return type says it returns a vc string. “DictListKeys” is the name of the vc function. The “13″ signifies that this function takes two arguments: an int and a string, in that order. The character “1″ represents a vc int, and the character “3″ represents a vc string.

The order of this list determines what integer represents each function in the vergec bytecode. Fun, eh?

Step 3.

Whenever you add a function to the libfuncs list, you must also increment the NUM_LIBFUNCS define in opcodes.h. libfuncs is a static array, and NUM_LIBFUNCS is that static array’s size declaration.

Step 4.

Finally, you must add a new case clause to the giant switch in VCCore::HandleLibFunc() within the vc_library.cpp file. The case’s integer is the opcode in the vergec bytecode that represents the function. This is the index of the function’s definition in the libfuncs array from step 2.

Step 5.

Compile a new verge.exe, and debug your function. Congrats, you’ve made your first vergec function.

Grue, why are you altering vc?

Good question, me. I thank myself for asking it.

Anyways, I wanted to add a way to get the list of vergec functions presently defined by the user in their system.vc code. To this end I first set out to make ListUserFunctionsm, which would work like ListBuiltinFunctions. However when I made this it failed horribly because I have so many functions: the string was simply too big for vc to handle. Not wanting to venture into vergec’s string handling functionality tonight, I looked for an alternate method.

Quickly I settled on a vc_GetUserFunctionCount() and GetUserFunctionByIdx() solution, which was better by far in my opinion instead of returning a ginormous pipe-character-delimited string. However, I failed at this for mysterious and retarded reasons unknown to me at this time. So… I’ve utterly failed where I was trying to rock.

But… why do you want those functions?

Excellent follow-up, self. 10 points to Ravenclaw.

While these two functions have several fun uses, I was making these functions so I could introduce a light unit-testing framework within vc. With some function-name introspection, I could find any function starting with, say, “grunit_” and use CallFunction() on it to execute said test. Making it automatically execute like that would be a great boon overall in the future, and would make it so I could develop a complicated system (such as say… a battle system) without fear of time lost in the future to hidden bugs caused by future feature implementation.

Yeah, that’s right. I’ve caught the Agile bug. Don’t ask why I’m still using vergec, though: I’ve only partially caught it. ;)

No SVN update this week. 4 hours in and I’ve still got a wash. I’m going to continue on, but I wanted to get this post out without too much more of a delay. So as I don’t feel bad about today, though, it should be noted that the development copy of breadbros.com improved by leaps and bounds today. Hooray!

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