Hello everyone,
I would like to know if and how Nim could be used as a C replacement to create
native dynamic system libraries which can be distributed and used like any
library written in C. This is where all the supposed C replacements like Rust
or Go fall flat. Only C++ so far seems suitable for that, but it's... well, C++.
Here is what I would like:
* Write a library in Nim
* Compile to a `.so` file, a DLL of whatever
* Generate the accompanying header file for distribution
I have been able to accomplish the first two points. Here is the Nim source
file:
# src/add5.nim
proc add5*(b: int): int {.exportc, dynlib.} =
b + 5
Run
I compiled it as `nim c -d:release --noMain --header:a.h --app:lib -o:lib/a.so
src/add5.nim`, this gave me the dynamic library which I was able to load into a
Python script:
from ctypes import cdll
a = cdll.LoadLibrary('./lib/a.so')
x = a.add5(4)
print(x)
Run
This works, but in order to make it properly distributable I need the header
file. The `--header:a.h` option does create a header file in
`~/.cache/nim/add5_r`, but this file looks like an intermediate build artifact,
not like something that can be distributed to `#include` in a C project.
/* Generated by Nim Compiler v1.6.0 */
#ifndef __a__
#define __a__
#define NIM_INTBITS 64
#define NIM_EmulateOverflowChecks
#include "nimbase.h"
#undef LANGUAGE_C
#undef MIPSEB
#undef MIPSEL
#undef PPC
#undef R3000
#undef R4000
#undef i386
#undef linux
#undef mips
#undef near
#undef far
#undef powerpc
#undef unix
N_LIB_PRIVATE N_NOCONV(void, signalHandler)(int sign);
N_LIB_PRIVATE N_NIMCALL(NI, getRefcount)(void* p);
N_LIB_IMPORT N_CDECL(NI, add5)(NI b);
N_LIB_IMPORT N_CDECL(void, NimMain)(void);
#endif /* __a__ */
Run
In particular, the included header file `nimbase.h` is stored under
`/usr/lib/nim/lib/nimbase.h`, which is not a regular include path.
So my question is, is it possible to use Nim to create independent standalone
dynamic C libraries? And if not, can this be added, or would such a feature be
considered out of scope?
