62 lines
2.5 KiB
Factor
62 lines
2.5 KiB
Factor
USING: kernel help.markup help.syntax sequences ;
|
|
IN: sets
|
|
|
|
ARTICLE: "sets" "Set-theoretic operations on sequences"
|
|
"Set-theoretic operations on sequences are defined on the " { $vocab-link "sets" } " vocabulary. These operations use hashtables internally to achieve linear running time."
|
|
$nl
|
|
"Remove duplicates:"
|
|
{ $subsection prune }
|
|
"Test for duplicates:"
|
|
{ $subsection all-unique? }
|
|
"Set operations on sequences:"
|
|
{ $subsection diff }
|
|
{ $subsection intersect }
|
|
{ $subsection union }
|
|
{ $see-also member? memq? contains? all? "assocs-sets" } ;
|
|
|
|
HELP: unique
|
|
{ $values { "seq" "a sequence" } { "assoc" "an assoc" } }
|
|
{ $description "Outputs a new assoc where the keys and values are equal." }
|
|
{ $examples
|
|
{ $example "USING: sets prettyprint ;" "{ 1 1 2 2 3 3 } unique ." "H{ { 1 1 } { 2 2 } { 3 3 } }" }
|
|
} ;
|
|
|
|
HELP: prune
|
|
{ $values { "seq" "a sequence" } { "newseq" "a sequence" } }
|
|
{ $description "Outputs a new sequence with each distinct element of " { $snippet "seq" } " appearing only once. Elements are compared for equality using " { $link = } " and elements are ordered according to their position in " { $snippet "seq" } "." }
|
|
{ $examples
|
|
{ $example "USING: sets prettyprint ;" "{ 1 1 t 3 t } prune ." "V{ 1 t 3 }" }
|
|
} ;
|
|
|
|
HELP: all-unique?
|
|
{ $values { "seq" sequence } { "?" "a boolean" } }
|
|
{ $description "Tests whether a sequence contains any repeated elements." }
|
|
{ $example
|
|
"USING: sets prettyprint ;"
|
|
"{ 0 1 1 2 3 5 } all-unique? ."
|
|
"f"
|
|
} ;
|
|
|
|
HELP: diff
|
|
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
|
|
{ $description "Outputs a sequence consisting of elements present in " { $snippet "seq1" } " but not " { $snippet "seq2" } ", comparing elements for equality."
|
|
} { $examples
|
|
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } diff ." "{ 1 }" }
|
|
} ;
|
|
|
|
HELP: intersect
|
|
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
|
|
{ $description "Outputs a sequence consisting of elements present in both " { $snippet "seq1" } " and " { $snippet "seq2" } "." }
|
|
{ $examples
|
|
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } intersect ." "{ 2 3 }" }
|
|
} ;
|
|
|
|
HELP: union
|
|
{ $values { "seq1" sequence } { "seq2" sequence } { "newseq" sequence } }
|
|
{ $description "Outputs a sequence consisting of elements present in " { $snippet "seq1" } " and " { $snippet "seq2" } " which does not contain duplicate values." }
|
|
{ $examples
|
|
{ $example "USING: sets prettyprint ;" "{ 1 2 3 } { 2 3 4 } union ." "V{ 1 2 3 4 }" }
|
|
} ;
|
|
|
|
{ diff intersect union } related-words
|