Introduce "Target" as an alias of "Range"

CAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "CAP",
 Subtitle := "Categories, Algorithms, Programming",
-Version := "2023.08-03",
+Version := "2023.08-04",
 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/CategoryMorphisms.gd

@@ -43,7 +43,13 @@ DeclareAttribute( "Source",
 DeclareAttribute( "Range",
                   IsCapCategoryMorphism );
 
-# this attribute is also an implied operation
+#! @Description
+#! The argument is a morphism $\alpha: a \rightarrow b$.
+#! The output is its target $b$.
+#! @Returns an object
+#! @Arguments alpha
+DeclareAttribute( "Target",
+                  IsCapCategoryMorphism );
 
 ###################################
 ##

CAP/gap/CategoryMorphisms.gi

@@ -58,6 +58,11 @@ InstallValue( PROPAGATION_LIST_FOR_EQUAL_MORPHISMS,
 ##
 ######################################
 
+InstallMethod( Target,
+               [ IsCapCategoryMorphism ],
+
+  Range );
+
 InstallMethod( Add,
                [ IsCapCategory, IsCapCategoryMorphism ],
 

CAP/gap/CategoryTwoCells.gd

@@ -27,6 +27,14 @@ DeclareAttribute( "Source",
 DeclareAttribute( "Range",
                   IsCapCategoryTwoCell );
 
+#! @Description
+#! The argument is a $2$-cell $c: \alpha \rightarrow \beta$.
+#! The output is its target $\beta$.
+#! @Returns a morphism
+#! @Arguments c
+DeclareAttribute( "Target",
+                  IsCapCategoryTwoCell );
+
 ###################################
 ##
 ## Properties

CAP/gap/CategoryTwoCells.gi

@@ -8,10 +8,15 @@ BindGlobal( "IsCapCategoryTwoCellRep", IsCapCategoryTwoCell );
 
 ####################################
 ##
-## Add function
+## Operations
 ##
 ####################################
 
+InstallMethod( Target,
+               [ IsCapCategoryTwoCell ],
+
+  Range );
+
 ##
 InstallMethod( Add,
                [ IsCapCategory, IsCapCategoryTwoCell ],

CompilerForCAP/PackageInfo.g

@@ -10,7 +10,7 @@ SetPackageInfo( rec(
 
 PackageName := "CompilerForCAP",
 Subtitle := "Speed up computations in CAP categories",
-Version := "2023.07-01",
+Version := "2023.08-01",
 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",
 

CompilerForCAP/gap/InferDataTypes.gi

@@ -937,6 +937,12 @@
 
 end );
 
+CapJitAddTypeSignature( "Target", [ IsCapCategoryMorphism ], function ( input_types )
+
+    return CapJitDataTypeOfObjectOfCategory( input_types[1].category );
+
+end );
+
 # GAP operations
 CapJitAddTypeSignature( "RETURN_TRUE", [ IsObject, IsObject ], IsBool );
 CapJitAddTypeSignature( "Length", [ IsList ], IsInt );

CompilerForCAP/gap/Logic.gi

@@ -509,7 +509,7 @@ CapJitAddLogicFunction( function ( tree )
 
                     return object.args.2;
 
-                elif attribute_name = "Range" then
+                elif attribute_name = "Range" or attribute_name = "Target" then
 
                     return object.args.3;
 
@@ -723,7 +723,7 @@ InstallGlobalFunction( CAP_JIT_INTERNAL_TELESCOPED_ITERATION, function ( tree, r
                     # Source can be recovered from initial_value
                     CapJitIsCallToGlobalFunction( source, "Source" ) and source.args.length = 1 and source.args.1.type = "EXPR_REF_FVAR" and source.args.1.func_id = result_func.id and source.args.1.name = result_func.nams[1] and
                     # Range can be recovered from initial_value
-                    CapJitIsCallToGlobalFunction( range, "Range" ) and range.args.length = 1 and range.args.1.type = "EXPR_REF_FVAR" and range.args.1.func_id = result_func.id and range.args.1.name = result_func.nams[1]
+                    CapJitIsCallToGlobalFunction( range, gvar -> gvar in [ "Range", "Target" ] ) and range.args.length = 1 and range.args.1.type = "EXPR_REF_FVAR" and range.args.1.func_id = result_func.id and range.args.1.name = result_func.nams[1]
                 then
 
                     case := "from_initial_value";

CompilerForCAP/gap/LogicTemplates.gi

@@ -477,9 +477,16 @@
 
             fi;
 
-            if template_tree.funcref.type = "EXPR_REF_GVAR" and not IsIdenticalObj( ValueGlobal( tree.funcref.gvar ), ValueGlobal( template_tree.funcref.gvar ) ) then
+            if template_tree.funcref.type = "EXPR_REF_GVAR" then
 
-                return fail;
+                if
+                    not IsIdenticalObj( ValueGlobal( tree.funcref.gvar ), ValueGlobal( template_tree.funcref.gvar ) ) and
+                    not (template_tree.funcref.gvar in [ "Range", "Target" ] and tree.funcref.gvar in [ "Range", "Target" ] and IsBound( tree.funcref.data_type ) and IsSpecializationOfFilter( IsCapCategoryMorphism, tree.funcref.data_type.signature[1][1].filter ))
+                then
+
+                    return fail;
+
+                fi;
 
             fi;
 
@@ -651,6 +658,15 @@
 
                     continue;
 
+                elif template_tree.gvar in [ "Range", "Target" ] and tree.gvar in [ "Range", "Target" ] and IsBound( tree.data_type ) and IsSpecializationOfFilter( IsCapCategoryMorphism, tree.data_type.signature[1][1].filter ) then
+
+                    if debug then
+                        # COVERAGE_IGNORE_NEXT_LINE
+                        Display( "match: gvars are both Range resp. Target of a morphism" );
+                    fi;
+
+                    continue;
+
                 else
 
                     if debug then