Update comment in LibGAP.jl/src/gap_to_julia.jl

Co-Authored-By: sebasguts <[email protected]>
oscar-system · Nov 29, 2018 · a6e4dab · a6e4dab
1 parent 55baa50
commit a6e4dab
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Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/LibGAP.jl/src/gap_to_julia.jl b/LibGAP.jl/src/gap_to_julia.jl
@@ -126,7 +126,7 @@ function gap_to_julia( ::Type{Array{Obj,1}}, obj :: MPtr , recursion_dict = IdDi
     new_array = Array{Any,1}( undef, len_list)
     recursion_dict[obj] = new_array
     for i in 1:len_list
-        current_obj = ElmList(obj,i)
+        current_obj = ElmList(obj,i)  # returns 'nothing' for holes in the list
         if haskey(recursion_dict,current_obj)
             new_array[ i ] = recursion_dict[current_obj]
         else
@@ -159,7 +159,7 @@ function gap_to_julia( ::Type{Array{T,1}}, obj :: MPtr, recursion_dict = IdDict(
     return new_array
 end
 
-## Special case for conversion of lists with holes
+## Special case for conversion of lists with holes; these are converted into 'nothing'
 function gap_to_julia( ::Type{Array{Union{Nothing,T},1}}, obj :: MPtr, recursion_dict = IdDict() ) where T
     if ! Globals.IsList( obj )
         throw(ArgumentError("<obj> is not a list"))

diff --git a/LibGAP.jl/test/conversion.jl b/LibGAP.jl/test/conversion.jl
@@ -112,7 +112,7 @@
     xx = GAP.julia_to_gap( "a" )
     @test_throws MethodError GAP.gap_to_julia( Dict{Int64,Int64}, xx )
 
-    ## Test nothing
+    ## Test converting GAP lists with holes in them
     xx = GAP.EvalString( "[1,,1]" )
     @test GAP.gap_to_julia(xx) == Any[1,nothing,1]
     @test GAP.gap_to_julia(Array{Any,1},xx) == Any[1,nothing,1]
@@ -222,7 +222,7 @@ end
     conv = GAP.julia_to_gap(d, Val(true));
     @test conv === conv.b
 
-    ## Test nothing
+    ## Test converting lists with 'nothing' in them -> should be converted to a hole in the list
     xx = GAP.EvalString( "[1,,1]" )
     @test GAP.julia_to_gap([1,nothing,1]) == xx