Manual argument type with MathLink C interface
- To: mathgroup at smc.vnet.net
- Subject: [mg129922] Manual argument type with MathLink C interface
- From: Szabolcs Horvát <szhorvat at gmail.com>
- Date: Tue, 26 Feb 2013 01:10:13 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- Delivered-to: l-mathgroup@wolfram.com
- Delivered-to: mathgroup-newout@smc.vnet.net
- Delivered-to: mathgroup-newsend@smc.vnet.net
When using the MathLink C interface, if we want to get arguments
manually, we need to put the following in the template (.tm) file:
:ArgumentTypes: { Manual }
:ReturnType: Manual
Note the braces around {Manual}. I accidentally used
:ArgumentTypes: Manual
:ReturnType: Manual
instead.
mprep does 'compile' this template file without errors, and generates
valid C code for it, but it doesn't have the same behaviour as the
standard :ArgumentTypes: {Manual} specification.
Diffing the outputs shows only one difference: the f_nargs member of
the "func" struct is set to -1 for this function with :ArgumentTypes:
Manual, while with {Manual} it is 0.
Question: Is :ArgumentTypes: Manual meaningful, and if yes, what is
its use? Is there going to be anything meaningful on the link that I
can MLGet, and if yes, what?
Admittedly, this is mostly of theoretical interest for me. I was just
curious why mprep didn't complain about this if it was something that
really wasn't allowed. Perhaps it does have some use.