Merge pull request #1695 from zickgraf/master

Further simplifications regarding the derivation mechanism

ActionsForCAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "ActionsForCAP",
 Subtitle := "Actions and Coactions for CAP",
-Version := "2024.09-01",
+Version := "2024.09-02",
 Date := (function ( ) if IsBound( GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE ) then return GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE; else return Concatenation( ~.Version{[ 1 .. 4 ]}, "-", ~.Version{[ 6, 7 ]}, "-01" ); fi; end)( ),
 License := "GPL-2.0-or-later",
 

ActionsForCAP/gap/ActionsCategory.gi

@@ -30,7 +30,7 @@ InstallMethod( LeftActionsCategory,
                [ IsCapCategoryObject, IsString, IsList ],
 
   function( acting_object, name, context_filter_list )
-    local underlying_monoidal_category, preconditions, category_weight_list, i,
+    local underlying_monoidal_category, preconditions, i,
           structure_record, object_constructor, morphism_constructor, 
           left_actions_category, identity_of_acting_object, tensor_preserves_epis;
 
@@ -111,14 +111,11 @@ InstallMethod( LeftActionsCategory,
 
     end;
 
-    ##
-    category_weight_list := underlying_monoidal_category!.derivations_weight_list;
-
     ## Left action for ZeroObject
     preconditions := [ "UniversalMorphismIntoZeroObject",
                        "TensorProductOnObjects" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.ZeroObject :=
           function( underlying_zero_object )
@@ -134,7 +131,7 @@ InstallMethod( LeftActionsCategory,
                        "DirectSumFunctorialWithGivenDirectSums",
                        "PreCompose" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.DirectSum :=
           function( obj_list, underlying_direct_sum )
@@ -160,7 +157,7 @@ InstallMethod( LeftActionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "LiftAlongMonomorphism" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_acting_object := IdentityMorphism( acting_object );
 
@@ -193,7 +190,7 @@ InstallMethod( LeftActionsCategory,
         Add( preconditions, "Colift" );
     fi;
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_acting_object := IdentityMorphism( acting_object );
 
@@ -285,7 +282,7 @@ InstallMethod( RightActionsCategory,
                [ IsCapCategoryObject, IsString, IsList ],
 
   function( acting_object, name, context_filter_list )
-    local underlying_monoidal_category, preconditions, category_weight_list, i,
+    local underlying_monoidal_category, preconditions, i,
           structure_record, object_constructor, morphism_constructor, 
           right_actions_category, identity_of_acting_object, tensor_preserves_epis;
 
@@ -366,14 +363,11 @@ InstallMethod( RightActionsCategory,
 
     end;
 
-    ##
-    category_weight_list := underlying_monoidal_category!.derivations_weight_list;
-
     ## Right action for ZeroObject
     preconditions := [ "UniversalMorphismIntoZeroObject",
                        "TensorProductOnObjects" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.ZeroObject :=
           function( underlying_zero_object )
@@ -389,7 +383,7 @@ InstallMethod( RightActionsCategory,
                        "DirectSumFunctorialWithGivenDirectSums",
                        "PreCompose" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.DirectSum :=
           function( obj_list, underlying_direct_sum )
@@ -415,7 +409,7 @@ InstallMethod( RightActionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "LiftAlongMonomorphism" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_acting_object := IdentityMorphism( acting_object );
 
@@ -448,7 +442,7 @@ InstallMethod( RightActionsCategory,
         Add( preconditions, "Colift" );
     fi;
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_acting_object := IdentityMorphism( acting_object );
 

ActionsForCAP/gap/CoactionsCategory.gi

@@ -29,7 +29,7 @@ InstallMethod( LeftCoactionsCategory,
                [ IsCapCategoryObject, IsString, IsList ],
 
   function( coacting_object, name, context_filter_list )
-    local underlying_monoidal_category, preconditions, category_weight_list, i,
+    local underlying_monoidal_category, preconditions, i,
           structure_record, object_constructor, morphism_constructor, 
           left_coactions_category, identity_of_coacting_object;
 
@@ -110,14 +110,11 @@ InstallMethod( LeftCoactionsCategory,
 
     end;
 
-    ##
-    category_weight_list := underlying_monoidal_category!.derivations_weight_list;
-
     ## Left coaction for ZeroObject
     preconditions := [ "UniversalMorphismIntoZeroObject",
                        "TensorProductOnObjects" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.ZeroObject :=
           function( underlying_zero_object )
@@ -133,7 +130,7 @@ InstallMethod( LeftCoactionsCategory,
                        "DirectSumFunctorialWithGivenDirectSums",
                        "PreCompose" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.DirectSum :=
           function( obj_list, underlying_direct_sum )
@@ -160,7 +157,7 @@ InstallMethod( LeftCoactionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "Lift" ]; #we can't use LiftAlongMonomorphism here because we don't know if the tensor product is left exact
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_coacting_object := IdentityMorphism( coacting_object );
 
@@ -185,7 +182,7 @@ InstallMethod( LeftCoactionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "ColiftAlongEpimorphism" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_coacting_object := IdentityMorphism( coacting_object );
 
@@ -263,7 +260,7 @@ InstallMethod( RightCoactionsCategory,
                [ IsCapCategoryObject, IsString, IsList ],
 
   function( coacting_object, name, context_filter_list )
-    local underlying_monoidal_category, preconditions, category_weight_list, i,
+    local underlying_monoidal_category, preconditions, i,
           structure_record, object_constructor, morphism_constructor, 
           right_coactions_category, identity_of_coacting_object;
 
@@ -345,13 +342,11 @@ InstallMethod( RightCoactionsCategory,
     end;
 
     ##
-    category_weight_list := underlying_monoidal_category!.derivations_weight_list;
-
     ## Right coaction for ZeroObject
     preconditions := [ "UniversalMorphismIntoZeroObject",
                        "TensorProductOnObjects" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.ZeroObject :=
           function( underlying_zero_object )
@@ -367,7 +362,7 @@ InstallMethod( RightCoactionsCategory,
                        "DirectSumFunctorialWithGivenDirectSums",
                        "PreCompose" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         structure_record.DirectSum :=
           function( obj_list, underlying_direct_sum )
@@ -394,7 +389,7 @@ InstallMethod( RightCoactionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "Lift" ]; #we can't use LiftAlongMonomorphism here because we don't know if the tensor product is left exact
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_coacting_object := IdentityMorphism( coacting_object );
 
@@ -419,7 +414,7 @@ InstallMethod( RightCoactionsCategory,
                        "TensorProductOnObjects", #belongs to TensorProductOnMorphisms
                        "ColiftAlongEpimorphism" ];
 
-    if ForAll( preconditions, c -> CurrentOperationWeight( category_weight_list, c ) < infinity ) then
+    if ForAll( preconditions, c -> CanCompute( underlying_monoidal_category, c ) ) then
 
         identity_of_coacting_object := IdentityMorphism( coacting_object );
 

CAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "CAP",
 Subtitle := "Categories, Algorithms, Programming",
-Version := "2024.09-28",
+Version := "2024.09-29",
 Date := (function ( ) if IsBound( GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE ) then return GAPInfo.SystemEnvironment.GAP_PKG_RELEASE_DATE; else return Concatenation( ~.Version{[ 1 .. 4 ]}, "-", ~.Version{[ 6, 7 ]}, "-01" ); fi; end)( ),
 License := "GPL-2.0-or-later",
 

CAP/gap/Derivations.gd

@@ -36,11 +36,9 @@ DeclareCategory( "IsDerivedMethod", IsAttributeStoringRep );
 
 #! @Description
 #!  Creates a new derivation object.
-#!  The argument <A>name</A> is an arbitrary name used to
-#!  identify this derivation, and is useful only for debugging
-#!  purposes.
 #!  The argument <A>target_op_name</A> is the name of the operation which
 #!  the derived method implements.
+#!  The argument <A>description</A> should describe the derivation.
 #!  The argument <A>used_ops_with_multiples</A> contains
 #!  
 #!  * the name of each operation used by the derived method,
@@ -53,23 +51,22 @@ DeclareCategory( "IsDerivedMethod", IsAttributeStoringRep );
 #!  category for which this derivation will be installed,
 #!  and return a category for which the operation in the first
 #!  entry must be installed for the derivation to be considered applicable.
+#!  The argument <A>func</A> contains the actual implementation of the
+#!  derived method.
 #!  The argument <A>weight</A> is an additional number to add
 #!  when calculating the resulting weight of the target operation
 #!  using this derivation. Unless there is any particular reason
 #!  to regard the derivation as exceedingly expensive, this number
 #!  should be <C>1</C>.
-#!  The argument <A>func</A> contains the actual implementation of the
-#!  derived method.
 #!  The argument <A>category_filter</A> is a filter (or function) describing
 #!  which categories the derivation is valid for. If it is valid
 #!  for all categories, then this argument should have the value
 #!  <C>IsCapCategory</C>. The output of <A>category_filter</A> must not
 #!  change during the installation of operations. In particular, it must
 #!  not rely on `CanCompute` to check conditions.
-#! @Arguments name, target_op, used_ops_with_multiples, weight, func, category_filter
-DeclareOperation( "MakeDerivation",
-                  [ IsString, IsString, IsDenseList,
-                    IsPosInt, IsFunction, IsFunction ] );
+#! @Arguments target_op_name, description, used_ops_with_multiples, func, weight, category_filter
+DeclareOperation( "CreateDerivation",
+                  [ IsString, IsString, IsDenseList, IsFunction, IsPosInt, IsFunction ] );
 
 #! @Description
 #!  A description of the derivation.

CAP/gap/Derivations.gi

@@ -26,10 +26,10 @@ InstallGlobalFunction( "DeactivateDerivationInfo",
     SetInfoLevel( DerivationInfo, 0 );
 end );
 
-InstallMethod( MakeDerivation,
-               [ IsString, IsString, IsDenseList, IsPosInt, IsFunction, IsFunction ],
+InstallMethod( CreateDerivation,
+               [ IsString, IsString, IsDenseList, IsFunction, IsPosInt, IsFunction ],
 
-function( description, target_op_name, used_op_names_with_multiples_and_category_getters, weight, func, category_filter )
+function( target_op_name, description, used_op_names_with_multiples_and_category_getters, func, weight, category_filter )
   local wrapped_category_filter, derivation;
 
     #= comment for Julia
@@ -236,12 +236,14 @@ InstallGlobalFunction( AddDerivation,
     fi;
     # =#
 
-    derivation := MakeDerivation( description,
-                                  target_op_name,
-                                  used_op_names_with_multiples_and_category_getters,
-                                  weight,
-                                  func,
-                                  category_filter );
+    derivation := CreateDerivation(
+        target_op_name,
+        description,
+        used_op_names_with_multiples_and_category_getters,
+        func,
+        weight,
+        category_filter
+    );
 
     if function_called_before_installation <> false then
 
@@ -452,7 +454,7 @@ BindGlobal( "TryToInstallDerivation", function ( owl, d )
 
     if new_weight < current_weight or (new_weight = current_weight and current_derivation <> fail and d!.position_in_derivations_by_target < current_derivation!.position_in_derivations_by_target) then
 
-        Info( DerivationInfo, 1, Concatenation( "install(",
+        Info( DerivationInfo, 1, Concatenation( "derive(",
                                                 String( new_weight ),
                                                 ") ",
                                                 target,
@@ -525,18 +527,9 @@ end );
 InstallMethod( AddPrimitiveOperation,
                [ IsOperationWeightList, IsString, IsInt ],
 function( owl, op_name, new_weight )
-  local current_weight;
-
-    Info( DerivationInfo, 1, Concatenation( "install(",
-                                  String( new_weight ),
-                                  ") ",
-                                  op_name,
-                                  ": primitive installation\n" ) );
-
-    current_weight := owl!.operation_weights.( op_name );
 
     owl!.operation_weights.( op_name ) := new_weight;
-    owl!.operation_derivations.( op_name ) := fail;
+    Assert( 0, owl!.operation_derivations.( op_name ) = fail );
 
 end );
 

CAP/gap/Finalize.gi

@@ -189,12 +189,12 @@ InstallGlobalFunction( AddFinalDerivationBundle, FunctionWithNamedArguments(
         fi;
         # =#
 
-        Add( derivations, MakeDerivation(
-            Concatenation( description, " (final derivation)" ),
+        Add( derivations, CreateDerivation(
             NameFunction( current_additional_func[1] ),
+            Concatenation( description, " (final derivation)" ),
             used_op_names_with_multiples_and_category_getters,
-            weight,
             current_additional_func[3],
+            weight,
             category_filter
         ) );
 
@@ -262,12 +262,12 @@ InstallGlobalFunction( AddFinalDerivationBundle, FunctionWithNamedArguments(
     fi;
 
     # only used to check if we can install all the derivations in `derivations`
-    dummy_derivation := MakeDerivation(
-        "dummy derivation",
+    dummy_derivation := CreateDerivation(
         "internal dummy function of a final derivation",
+        "dummy derivation",
         used_op_names_with_multiples_and_category_getters,
-        1,
         ReturnTrue,
+        1,
         category_filter
     );
 
@@ -318,6 +318,12 @@ InstallMethod( Finalize,
 
             if weight_list!.operation_weights.(op_name) <> infinity and weight_list!.operation_derivations.(op_name) = fail then
 
+                Info( DerivationInfo, 1, Concatenation( "add(",
+                                                        String( weight_list!.operation_weights.(op_name) ),
+                                                        ") ",
+                                                        op_name,
+                                                        ": primitive installation\n" ) );
+
                 InstallDerivationsUsingOperation( weight_list, op_name );
 
             fi;
@@ -390,7 +396,7 @@ InstallMethod( Finalize,
                     # the derivations provided in the bundle.
                     if new_weight <= current_weight then
 
-                        Info( DerivationInfo, 1, Concatenation( "install(",
+                        Info( DerivationInfo, 1, Concatenation( "derive(",
                                                                 String( new_weight ),
                                                                 ") ",
                                                                 op_name,