improved the manual of the GAP package JuliaInterface

- added documentation for many GAP functions
- reordered some GAP code such that the ordering fits to the documentation
- added a few `JuliaToGAP` conversions (which were marked as "TODO")

pkg/GAPJulia/JuliaInterface/PackageInfo.g

@@ -1,5 +1,5 @@
 #
-# JuliaInterface: Test interface to julia
+# JuliaInterface: Interface to Julia
 #
 # This file contains package meta data. For additional information on
 # the meaning and correct usage of these fields, please consult the
@@ -9,7 +9,7 @@
 SetPackageInfo( rec(
 
 PackageName := "JuliaInterface",
-Subtitle := "Test interface to julia",
+Subtitle := "Interface to Julia",
 Version := "0.2.6",
 Date := "04/02/2020", # dd/mm/yyyy format
 License := "GPL-2.0-or-later",
@@ -75,11 +75,11 @@ PackageDoc := [ rec(
   HTMLStart := "doc/chap0.html",
   PDFFile   := "doc/manual.pdf",
   SixFile   := "doc/manual.six",
-  LongTitle := "Test interface to julia",
+  LongTitle := "Interface to &Julia;",
 ) ],
 
 Dependencies := rec(
-  GAP := ">= 4.11",    # need support for the component 'BannerFunction'
+  GAP := ">= 4.11",    # need compatible code in GAP's src/julia_gc.c
   NeededOtherPackages := [ ],
   SuggestedOtherPackages := [ ],
   ExternalConditions := [ ],

pkg/GAPJulia/JuliaInterface/gap/BindCFunction.gd

@@ -7,27 +7,33 @@
 ##    Sebastian Gutsche, Siegen University
 ##
 #! @Chapter Function integration
-##
-#############################################################################
 
-#! @Section Julia functions in GAP
+#! @Section &Julia; functions in ⪆
 
-#! @Arguments julia_name, nr_args, arg_names
+#! @Arguments julia_name, arg_names
 #! @Returns a function
 #! @Description
-#!  Returns a GAP function that acts like a kernel function in GAP,
-#!  but calls the Julia function <A>julia_name</A>. The function in Julia
-#!  must exist, bound to the global name <A>julia_name</A> in the module <C>Main</C>,
-#!  and must be callable on <A>nr_args</A> arguments. <A>arg_name</A> must
-#!  be a list of strings of length <A>nr_args</A> describing the argument names
+#!  Returns a &GAP; function that acts like a kernel function in &GAP;,
+#!  but calls the &Julia; function <A>julia_name</A>.
+#!  The function in &Julia; must exist, be bound to the global name
+#!  <A>julia_name</A> in the module <C>Main</C>,
+#!  and must be callable on as many arguments as the length of the list
+#!  <A>arg_names</A> of strings describing the argument names
 #!  that are displayed in the function header by &GAP;.
+#! @BeginExampleSession
+#! ...
+#! @EndExampleSession
 DeclareGlobalFunction( "JuliaBindCFunction" );
 
 #! @Section GAP functions in Julia
 
 #! @Arguments func, name, argument_number
 #! @Returns nothing
 #! @Description
-#!  Sets the function <A>func</A> in Julia as <C>GAP.</C><A>name</A>.
-#!  The resulting function is then callable from Julia on <A>argument_number</A> arguments.
+#!  Sets the function <A>func</A> in &Julia; as <C>GAP.</C><A>name</A>.
+#!  The resulting function is then callable from &Julia; on <A>argument_number</A> arguments.
+#! @BeginExampleSession
+#! ...
+#! @EndExampleSession
+#! TODO: Does this function ever get installed?
 DeclareGlobalFunction( "JuliaSetGAPFuncAsJuliaObjFunc" );

pkg/GAPJulia/JuliaInterface/gap/BindCFunction.gi

@@ -24,7 +24,7 @@ InstallGlobalFunction( JuliaBindCFunction,
         arg_names := List( arg_names, Immutable );
         MakeImmutable( arg_names );
     else
-        ErrorNoReturn( "second argument must be a string or a a list of strings" );
+        ErrorNoReturn( "second argument must be a string or a list of strings" );
     fi;
 
     nr_args := Length( arg_names );