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# SPDX-License-Identifier: GPL-2.0-or-later
# CAP: Categories, Algorithms, Programming
#
# Declarations
#
#! @Chapter The Category Constructor
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#
#! @Section Info class
#
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#! @Description
#! Info class controlling the debugging output of <Ref Oper="CategoryConstructor" Label="for IsRecord" />.
DeclareInfoClass( "InfoCategoryConstructor" );
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#
#! @Section Constructors
#
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#! @Description
#! Creates a &CAP; category subject to the options given via <A>options</A>,
#! which is a record with the following keys:
#! * `name` (optional): name of the category
#! * `category_filter`, `category_object_filter`, `category_morphism_filter` (mandatory): passed to <Ref Func="CreateCapCategoryWithDataTypes" />
#! * `object_datum_type`, `morphism_datum_type` (optional): passed to <Ref Func="CreateCapCategoryWithDataTypes" />
#! * `commutative_ring_of_linear_category` (optional): ring attached as <Ref Attr="CommutativeRingOfLinearCategory" Label="for IsCapCategory" /> to the category
#! * `range_category_of_homomorphism_structure` (optional): category attached as <Ref Attr="RangeCategoryOfHomomorphismStructure" Label="for IsCapCategory" /> to the category (or the string "self" to attach the category to itself)
#! * `properties` (optional): list of categorical properties the category will have, see `CAP_INTERNAL_CATEGORICAL_PROPERTIES_LIST`
#! * `object_constructor` (optional): function added as an installation of <Ref Oper="ObjectConstructor" Label="for IsCapCategory, IsObject" /> to the category
#! * `object_datum` (optional): function added as an installation of <Ref Oper="ObjectDatum" Label="for IsCapCategoryObject" /> to the category
#! * `morphism_constructor` (optional): function added as an installation of <Ref Oper="MorphismConstructor" Label="for IsCapCategoryObject, IsObject, IsCapCategoryObject" /> to the category
#! * `morphism_datum` (optional): function added as an installation of <Ref Oper="MorphismDatum" Label="for IsCapCategoryMorphism" /> to the category
#! * `list_of_operations_to_install` (mandatory): a list of names of &CAP; operations which should be installed for the category
#! * `is_computable` (optional): whether the category can decide `IsCongruentForMorphisms`
#! * `supports_empty_limits` (optional): whether the category supports empty lists in inputs to operations of limits and colimits
#! * `underlying_category_getter_string` (optional): see below
#! * `underlying_category` (optional): see below
#! * `underlying_object_getter_string` (optional): see below
#! * `underlying_morphism_getter_string` (optional): see below
#! * `top_object_getter_string` (optional): see below
#! * `top_morphism_getter_string` (optional): see below
#! * `generic_output_source_getter_string` (optional): see below
#! * `generic_output_range_getter_string` (optional): see below
#! * `create_func_bool`: see below
#! * `create_func_object`: see below
#! * `create_func_morphism`: see below
#! * `create_func_list_of_objects`: see below
#!
#! The values of the keys `create_func_*` should be either the string `"default`" or functions which accept the category and the name of a &CAP; operation
#! of the corresponding `return_type`. Values for return types occuring for operations in `list_of_operations_to_install` are mandatory.
#! The functions must return either strings or pairs of a string and an integer:
#! The strings (after some replacements described below) will be evaluated and added as installations of the corresponding operations to the category with weights given by the integer (if provided).
#! The value `"default"` chooses a suitable default string (see the implementation for details) and gets the weights from `underlying_category`.
#! The following placeholders may be used in the strings and are replaced automatically:
#! * `operation_name` will be replaced by the name of the operation
#! * `input_arguments...` will be replaced by the `input_arguments_names` specified in the method name record (see <Ref Sect="Section_method_name_record_entries" />)
#! * `underlying_arguments...`: If the constructed category is created from another category, `underlying_category_getter_string`, `underlying_object_getter_string`, and
#! `underlying_morphism_getter_string` may be strings of functions computing the underlying category (when applied to the constructed category) and
#! the underlying object resp. morphism (when applied to the constructed category and an object resp. morphism in the constructed category).
#! These functions are applied to `input_arguments` and `underlying_arguments` is replaced by the result.
#! * `number_of_arguments` will be replaced by the number of input/underlying arguments
#! * `top_source` and `top_range`: If the return type is `morphism`, source and range are computed if possible and `top_source` and `top_range` are replaced by the results.
#! For computing source and range, the `output_source_getter_string` and `output_range_getter_string` from the method name record are used if available (see <Ref Sect="Section_method_name_record_entries" />).
#! In some categories, source and range can always be obtained in a generic way (e.g. from the morphism datum). In this case, `generic_output_source_getter_string` and `generic_output_range_getter_string`
#! can be set and are used if the required information is not available in the method name record.
#! * `top_object_getter` and `top_morphism_getter` are used in the `"default"` strings and are replaced by `top_object_getter_string` and `top_morphism_getter_string`, respectively.
#! @Arguments options
#! @Returns a &CAP; category
DeclareOperation( "CategoryConstructor",
[ IsRecord ] );
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