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* Copyright (c) 2002 by Michael J. Roberts. All Rights Reserved.
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* Please see the accompanying license file, LICENSE.TXT, for information
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* on using and copying this software.
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vmcore.h - T3 VM "core" interpreter - example function set definition
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This is an example of how to define custom intrinsic (i.e., native C++)
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functions for the T3 VM. An intrinsic function is a function written in
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C++, and part of the application executable, that can be called from TADS
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code (i.e., from within .t source).
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This file can be used as a template for creating custom intrinsics.
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Simply make a copy of this entire file, and then make the following
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1. Change the #ifndef symbol from VMCORE_H to a different name of your
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own choosing - usually, the name matches the name of the .h file itself.
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This symbol appears three times in the file, so you should be careful to
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change all three to the same new symbol.
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2. Change the name of class CVmBifSample to a name of your own choosing.
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Choose a name that describes the custom function set you're defining. This
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name appears in the class definition and also in each entry in the list
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near the bottom of the file, so make sure to change every occurrence of the
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name to the same new name.
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3. Change the names of the functions themselves. Note that each function
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name appears twice - first in the class definition near the start of the
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file, then again in the initialization list at the bottom of the file. You
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can add and delete functions as you wish. If you add new functions, simply
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copy an existing definition and change its name, being sure to add the
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function in both the class definition and the list at the bottom of the
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4. You must, of course, provide an implementation for each of your
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functions. Do that in a new .cpp file corresponding to your new header
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file. Make sure you #include your new header file from your new .cpp file.
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You can use the implementations in vmcore.cpp as a template for your new
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5. Make a copy of the file vmbifreg_core.cpp. Add a #include line for
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the new copy of this file you have created (you can add it right after the
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#include for vmbiftad.h). Also add a MAKE_ENTRY() line for your new
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function set - you can add it where the comments indicate in your copy of
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vmbifreg_core.cpp. The MAKE_ENTRY() line would look like this:
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MAKE_ENTRY("core-sample/010000", G_bif_core_sample);
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Use the same name you use for the variable defined in the initialization
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list near the end of the file. For the string, you can use anything you
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want, but you should choose something reasonably long and descriptive to
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avoid overlapping with anyone else's function set identifiers.
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6. Take vmbifreg_core.obj out of the application build, and replace it
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with the copy you created in step 5.
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7. Take vmcore.obj out of the application build, and replace it with your
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new .cpp file from step 4.
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8. Change the variable name G_bif_sample near the end of this file to a
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different name of your own choosing.
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9. Create a TADS header file, for inclusion in your TADS (.t) source
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code, defining your intrinsic functions. See the sample file "core.h"
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intrinsic 'core-sample/010000'
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// display the given string
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// read a line of text from the keyboard, and return it as a string
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You MUST define the intrinsic functions in the EXACT SAME ORDER that they
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appear in the initialization list near the end of this file. For the name
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of the function set (the 'core-sample/010000' string), you must use the
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EXACT SAME string you used in the MAKE_ENTRY() definition in step 5.
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Everything else in this file is boilerplate text, so you shouldn't have
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to change anything else.
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04/06/02 MJRoberts - Creation
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/* ------------------------------------------------------------------------ */
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* Our sample built-in functions. Each function we define here will be
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* callable as an intrinsic function from TADS source code.
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* This is only the interface definition. The actual implementations of
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* these functions appear in our .cpp file.
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* Note that every function has the same C++ interface. This has nothing
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* to do with the arguments that the TADS program passes to these
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* functions; the functions get their TADS arguments from the VM stack.
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* See the implementations for details.
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class CVmBifSample: public CVmBif
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static void display_text(VMG_ uint argc);
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static void read_text(VMG_ uint argc);
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#endif /* VMCORE_H */
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/* ------------------------------------------------------------------------ */
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* Sample function set vector. Define this only if VMBIF_DEFINE_VECTOR has
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* IMPORTANT - this definition is outside the #ifdef VMCORE_H section of
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* the header file, because we specifically want this part of the file to
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* be able to be included multiple times.
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* ALSO IMPORTANT - the ORDER of the definitions here is significant. You
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* must use the EXACT SAME ORDER in your "intrinsic" definition in the
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* header file you create for inclusion in your TADS (.t) source code.
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#ifdef VMBIF_DEFINE_VECTOR
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void (*G_bif_sample[])(VMG_ uint) =
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&CVmBifSample::display_text,
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&CVmBifSample::read_text
added
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tads/tads3/vmcore.h
