[GAP Forum] Source code of GAP

[Christopher Jefferson]

For operations like CharacterTable, there are several implementations in GAP. To find out what is actually called, you can (often) use 'ApplicableMethod', which accepts a function and it's arguments (as a list)

For example, Print(ApplicableMethod(CharacterTable, [AlternatingGroup(5)])) shows the function for finding this character table.

Unfortunately, if we try the same for primitive root, we get:

gap> Print(ApplicableMethod(PrimitiveRoot, [GF(3^5)]));



function ( object )
    <<kernel or compiled code>>
end

This tells us this code is not written in GAP, but instead in C.




On 16/04/2016, 12:33, "forum-bounces at gap-system.org on behalf of fatemeh moftakhar" <forum-bounces at gap-system.org on behalf of f.k.moftakhar at gmail.com> wrote:

>Dear Forum
>
>The command "Print(ff)" in GAP gives the code of the "ff" written in GAP.
>See for example the following command in GAP:
>gap> Print(Combinations);
>function ( arg )
>    local  combs, mset;
>    if Length( arg ) = 1  then
>        mset := ShallowCopy( arg[1] );
>        Sort( mset );
>        combs := CombinationsA( mset, 1, Length( mset ), [  ], 1 );
>    elif Length( arg ) = 2  then
>        mset := ShallowCopy( arg[1] );
>        Sort( mset );
>        combs := CombinationsK( mset, 1, Length( mset ), arg[2], [  ], 1 );
>    else
>        Error( "usage: Combinations( <mset> [, <k>] )" );
>    fi;
>    return combs;
>end
>
>If I run the command "Print(CharacterTable)", then we can see the following
>GAP message:
>
>gap> Print(CharacterTable);
><Operation "CharacterTable">
>
>Is it possible to find the GAP code for CharacterTable?
>
>If no, is it possible to find the source of the program for calculating
>with primitive roots of unity in GAP?
>
>finally where is the library of primitive roots of unity? For example I
>need to source program of GAP for computing E(8)-E(8)^3?
>
>Best regards
>Fatemeh Moftakhar
>
>-- 
>Regards;
>Miss Fatemeh Moftakhar
>PhD Candidate,
>Department of Pure Mathematics,
>Faculty of Mathematical Sciences,
>University of Kashan, Kashan, Iran
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