USING: help.syntax help.markup kernel prettyprint sequences quotations math ; IN: sequences.lib HELP: map-withn { $values { "seq" sequence } { "quot" quotation } { "n" number } { "newseq" sequence } } { $description "A generalisation of " { $link map } ". The first " { $snippet "n" } " items after the quotation will be " "passed to the quotation given to map-withn for each element in the sequence." } { $examples { $example "USING: math sequences.lib prettyprint ;" "1 2 3 4 { 6 7 8 9 10 } [ + + + + ] 4 map-withn .s" "{ 16 17 18 19 20 }" } } { $see-also each-withn } ; HELP: each-withn { $values { "seq" sequence } { "quot" quotation } { "n" number } } { $description "A generalisation of " { $link each } ". The first " { $snippet "n" } " items after the quotation will be " "passed to the quotation given to each-withn for each element in the sequence." } { $see-also map-withn } ; HELP: if-seq { $values { "seq" sequence } { "quot1" quotation } { "quot2" quotation } } { $description "Makes an implicit check if the sequence is empty. If the sequence has any elements, " { $snippet "quot1" } " is called on it. Otherwise, the empty sequence is dropped and " { $snippet "quot2" } " is called." } { $example "USING: kernel prettyprint sequences sequences.lib ;" "{ 1 2 3 } [ sum ] [ \"empty sequence\" throw ] if-seq ." "6" } ; HELP: if-empty { $values { "seq" sequence } { "quot1" quotation } { "quot2" quotation } } { $description "Makes an implicit check if the sequence is empty. An empty sequence is dropped and " { $snippet "quot1" } " is called. Otherwise, if the sequence has any elements, " { $snippet "quot2" } " is called on it." } { $example "USING: kernel prettyprint sequences sequences.lib ;" "{ 1 2 3 } [ \"empty sequence\" ] [ sum ] if-empty ." "6" } ; { if-seq if-empty } related-words