R help - Mar 2019 - Unobtainable source code of specific functions

Dear all,

I currently work on a translation of a cost surface function from R to Python
for my dissertation at university. In this context, I have to understand the
"AccCost" method (https://rdrr.io/cran/gdistance/src/R/accCost.R).
This method calls the function "shortest.paths" among other functions.
This is precisely the function that computes the cost surface so I found the
source code with "getAnywhere(shortest.paths())", but my problem is
that this code calls other functions that cannot be accessed with getAnywhere or
on the web... These functions are "C_R_igraph_finalizer",
"C_R_igraph_get_graph_id" and "C_R_igraph_shortest_paths".
My question is therefore the following, how or where could I find these source
code ? (Note : I have the package Igraph installed)

Thanks a lot for the help,

Julien Lacroix

On Thu, 14 Mar 2019 15:44:07 +0100 (CET)
julien.lacroix at student.uliege.be wrote:
> My question is therefore the following, how or where could I find
> these source code ? (Note : I have the package Igraph installed)
Functions wrapped in .Call() are implemented in a compiled language,
with corresponding sources in the src/ directory of a package.

For example, the call to C_R_igraph_shortest_paths seems to end up in
https://github.com/igraph/igraph/blob/6faf5610b8ab0175466e93a8a1d1981987976a38/src/structural_properties.c#L460

-- 
Best regards,
Ivan