Add cmath polar functions

[virendrakabra14]

Adds phase, polar, and rect functions to cmath module.

[virendrakabra14]

I tried using (LPython) math functions in cmath, but the import failed with this message

Module __main__ dependencies must contain math because a function present in it is getting called in __main__

I wasn't sure on where to add this dependency, so I created rect function in lfortran_intrinsics files.

[czgdp1807]

Windows build fails due to some syntax errors. See, https://github.com/lcompilers/lpython/actions/runs/4595681671/jobs/8116223194?pr=1663

[czgdp1807]

I tried using (LPython) math functions in cmath, but the import failed with this message

Module __main__ dependencies must contain math because a function present in it is getting called in __main__

I wasn't sure on where to add this dependency, so I created rect function in lfortran_intrinsics files.

Can you share the exact LPython command you executed?

[czgdp1807]

@virendrakabra14 I pushed some changes, let's see if they work with Windows CI or not.

[virendrakabra14]

@virendrakabra14 I pushed some changes, let's see if they work with Windows CI or not.

@czgdp1807 Alright.

I had also modified lfortran_intrinsics.c to resolve the Windows issue - double complex, double_complex_t aren't identified.

LFORTRAN_API double_complex_t _lfortran_rect(double r, double phi)
{
    double re = r*cos(phi);
    double im = r*sin(phi);
    #ifdef _MSC_VER
        _Dcomplex c = _DCOMPLEX_(re, im);
    #else
        double complex c = CMPLX(re, im);
    #endif
    return c;
}

I am guessing that would also work.

[czgdp1807]

I think we didn't need to go into C to implement rect. Using, _lfortran_dcos and _lfortran_dsin in cmath.py completes the implementation. Not sure what added advantage C implementation provides.

[virendrakabra14]

I tried using (LPython) math functions in cmath, but the import failed with this message

Module __main__ dependencies must contain math because a function present in it is getting called in __main__

I wasn't sure on where to add this dependency, so I created rect function in lfortran_intrinsics files.

Can you share the exact LPython command you executed?

I was using import math in cmath.py and using sin, cos functions. Test file test_cmath.py was same as the current one. Then

lpython ./integration_tests/test_cmath.py

gave that error - which I think is due to importing math in cmath.

[czgdp1807]

Also, eventually we might implement all these intrinsics using IntrinsicFunction infrastructure and provide direct ASR implementations for their functions. So if calling into C can be avoided then it should be. In the long run, functions like, _lfortran_dsin, _lfortran_dcos can also be done via ASR directly (by using some approximation algorithms to produce outputs for sin and cos calls).