-! (c)2009 Joe Groff bsd license
-USING: kernel math tools.test variants ;
+! Copyright (C) 2009 Joe Groff.
+! See https://factorcode.org/license.txt for BSD license.
+USING: kernel math tools.test variants slots ;
IN: variants.tests
VARIANT: list
cons: { { first object } { rest list } }
;
-[ t ] [ nil list? ] unit-test
-[ t ] [ 1 nil <cons> list? ] unit-test
-[ f ] [ 1 list? ] unit-test
+{ t } [ nil list? ] unit-test
+{ t } [ 1 nil <cons> list? ] unit-test
+{ f } [ 1 list? ] unit-test
: list-length ( list -- length )
{
{ cons [ nip list-length 1 + ] }
} match ;
-[ 4 ]
+{ 4 }
[ 5 6 7 8 nil <cons> <cons> <cons> <cons> list-length ] unit-test
+
+{ nil t } [ list initial-value ] unit-test
+
+VARIANT: list2 ;
+VARIANT-MEMBER: list2 nil2 ;
+VARIANT-MEMBER: list2 cons2: { { first object } { rest list2 } } ;
+
+{ t } [ nil2 list2? ] unit-test
+{ t } [ 1 nil2 <cons2> list2? ] unit-test
+{ f } [ 1 list2? ] unit-test
+
+: list2-length ( list2 -- length )
+ {
+ { nil2 [ 0 ] }
+ { cons2 [ nip list2-length 1 + ] }
+ } match ;
+
+{ 4 }
+[ 5 6 7 8 nil2 <cons2> <cons2> <cons2> <cons2> list2-length ] unit-test