Let Display for functions print where it was defined

... at least when that information is available

Author: fingolfin

lib/function.gi

@@ -62,6 +62,14 @@ end);
 
 InstallMethod(Display, "for a function", [IsFunction and IsInternalRep],
 function(fun)
+    local loc;
+    loc := FilenameFunc(fun);
+    if loc <> fail and loc <> "stream" and loc <> "*stdin*" and loc <> "*errin*" then
+        loc := LocationFunc(fun);
+        if loc <> fail then
+            Print("# ", loc, "\n");
+        fi;
+    fi;
     Print(fun, "\n");
 end);
 

tst/testinstall/grpreps.tst

@@ -18,4 +18,3 @@ gap> List( res2[2], r -> [ r.field, r.dimension ] );
 
 #
 gap> STOP_TEST( "grpreps.tst" );
-

tst/testinstall/opers/BindingsOfClosure.tst

@@ -38,7 +38,7 @@ rec( NewAorP := function( name, filter, args... ) ... end,
   reqs := [ <Filter "(IsMagmaWithInverses and IsAssociative)">, 
       <Category "IsListOrCollection">, <Category "IsList">, 
       <Category "IsList">, <Category "IsFunction"> ], usetype := false )
-gap> Display(f);
+gap> Print(f, "\n");
 function ( G, D )
     if D = MovedPoints( G ) then
         return op( G );

tst/testinstall/varargs.tst

@@ -75,6 +75,7 @@ Syntax error: ) expected in stream:1
 function(a,b....) end;
                ^
 gap> Display(RETURN_FIRST);
+# src/gap.c:RETURN_FIRST
 function ( first, rest... )
     <<kernel code>> from src/gap.c:RETURN_FIRST
 end

tst/testspecial/print-compiled-func.g.out

@@ -3,6 +3,7 @@ function ( opr, info, rel, flags, baserank, method )
     <<compiled GAP code>> from GAPROOT/lib/oper1.g:LINE
 end
 gap> Display(InstallMethod);
+# GAPROOT/lib/oper1.g:LINE
 function ( arg... )
     <<compiled GAP code>> from GAPROOT/lib/oper1.g:LINE
 end