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#############################################################################
##
## This file is part of GAP, a system for computational discrete algebra.
## This file's authors include Thomas Breuer, Frank Celler.
##
## Copyright of GAP belongs to its developers, whose names are too numerous
## to list here. Please refer to the COPYRIGHT file for details.
##
## SPDX-License-Identifier: GPL-2.0-or-later
##
## This file deals with booleans.
##
#############################################################################
##
#C IsBool(<obj>) . . . . . . . . . . . . . . . . . . . category of booleans
##
## <#GAPDoc Label="IsBool">
## <ManSection>
## <Filt Name="IsBool" Arg='obj' Type='Category'/>
##
## <Description>
## tests whether <A>obj</A> is <K>true</K>, <K>false</K> or <K>fail</K>.
## <Example><![CDATA[
## gap> IsBool( true ); IsBool( false ); IsBool( 17 );
## true
## true
## false
## ]]></Example>
## </Description>
## </ManSection>
## <#/GAPDoc>
##
DeclareCategoryKernel( "IsBool", IsObject, IS_BOOL );
#############################################################################
##
#V BooleanFamily . . . . . . . . . . . . . . . . . . . . family of booleans
##
## <ManSection>
## <Var Name="BooleanFamily"/>
##
## <Description>
## </Description>
## </ManSection>
##
BIND_GLOBAL( "BooleanFamily",
NewFamily( "BooleanFamily", IS_BOOL ) );
#############################################################################
##
#F TYPE_BOOL . . . . . . . . . . . . . . . . . . . type of internal booleans
##
## <ManSection>
## <Func Name="TYPE_BOOL" Arg='obj'/>
##
## <Description>
## </Description>
## </ManSection>
##
BIND_GLOBAL( "TYPE_BOOL",
NewType( BooleanFamily, IS_BOOL and IsInternalRep ) );
#############################################################################
##
#M String( <bool> ) . . . . . . . . . . . . . . . . . . . . . for a boolean
##
InstallMethod( String,
"for a boolean",
true,
[ IsBool ], 0,
function( bool )
if bool = true then
return "true";
elif bool = false then
return "false";
elif bool = fail then
return "fail";
else
Error( "unknown boolean <bool>" );
fi;
end );
InstallMethod( ViewString, "for a boolean",
true, [ IsBool ], 5,
String );
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