Currently there is absolutely no documentation for working with Complex numbers at the level of the C API.
Apart from two macros defined [here] for setting the real and imag
values of Complex numbers there is no 'official' way of working with Complex numbers at the level of the C API.
I propose two things:
Fully document existing Complex number routines.
Provide a robust and efficient API for dealing with complex numbers from C extensions.
Isn't it enough to just use rb_funcall() to call Ruby methods on Complex numbers?
Calling Ruby methods in C extensions defeats the purpose of writing a C extension since a non-trivial number of Ruby method calls take up significant time.
RCOMPLEX_SET_REAL and RCOMPLEX_SET_IMAG are internal macros, and so I think they should not be used outside.
Both these macros are included in the ruby.h so I thought they're public. Maybe you want to remove them from there?
Isn't it enough to just use rb_funcall() to call Ruby methods on Complex numbers?
Calling Ruby methods in C extensions defeats the purpose of writing a C extension since a non-trivial number of Ruby method calls take up significant time.
What APIs do you need?
A concrete list, please.
RCOMPLEX_SET_REAL and RCOMPLEX_SET_IMAG are internal macros, and so I think they should not be used outside.
Both these macros are included in the ruby.h so I thought they're public. Maybe you want to remove them from there?
Isn't it enough to just use rb_funcall() to call Ruby methods on Complex numbers?
Calling Ruby methods in C extensions defeats the purpose of writing a C extension since a non-trivial number of Ruby method calls take up significant time.
The existing Ruby methods should already be fast enough for most cases.
C macros/functions for accessing the real and the imaginary parts seems fine, but I think not more than that should be exposed for Complex.
Isn't it enough to just use rb_funcall() to call Ruby methods on Complex numbers?
Calling Ruby methods in C extensions defeats the purpose of writing a C extension since a non-trivial number of Ruby method calls take up significant time.
What APIs do you need?
A concrete list, please.
As Benoit says (rightly), I don't think we need a very elaborate API. Therefore the following functions would be sufficient:
Constructor from double: Something like rb_complex_new(double real, double imag).
Access real and imag parts: Something like rb_complex_get_real(VALUE complex_number) and rb_complex_get_imag(VALUE complex_number).
Basic operations: complement, addition, subtraction, multiplication and division.
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