delete
clear-set
union!
+ diff!
}
"To test if a set is the empty set:"
{ $subsections null? }
{ $description "Adds all members from " { $snippet "set2" } " to " { $snippet "set1" } "." }
{ $side-effects "set1" } ;
+HELP: diff!
+{ $values { "set1" set } { "set2" set } }
+{ $description "Removes all members from " { $snippet "set1" } " contained in " { $snippet "set2" } "." }
+{ $side-effects "set1" } ;
+
HELP: intersects?
{ $values { "set1" set } { "set2" set } { "?" "a boolean" } }
{ $description "Tests if " { $snippet "set1" } " and " { $snippet "set2" } " have any elements in common." }
[ f ] [ { } intersection ] unit-test
[ HS{ } ] [ { HS{ } } intersection ] unit-test
[ HS{ 1 } ] [ { HS{ 1 2 3 } HS{ 1 } } intersection ] unit-test
+
+[ HS{ } ] [ HS{ } HS{ } diff! ] unit-test
+[ HS{ 1 } ] [ HS{ 1 2 3 } HS{ 2 3 } diff! ] unit-test
+[ HS{ 1 } ] [ HS{ 1 } HS{ 2 3 4 } diff! ] unit-test
+[ HS{ 1 2 3 } ] [ HS{ 1 2 3 } HS{ 4 } diff! ] unit-test
: union! ( set1 set2 -- set1 )
?members over [ adjoin ] curry each ;
+: diff! ( set1 set2 -- set1 )
+ dupd sequence/tester [ dup ] prepose pick
+ [ delete ] curry [ [ drop ] if ] curry compose each ;
+
! Temporarily for compatibility
: unique ( seq -- assoc )