41 lines
1.8 KiB
Factor
Executable File
41 lines
1.8 KiB
Factor
Executable File
USING: help.syntax help.markup kernel prettyprint sequences
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quotations math ;
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IN: sequences.lib
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HELP: map-withn
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{ $values { "seq" sequence } { "quot" quotation } { "n" number } { "newseq" sequence } }
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{ $description "A generalisation of " { $link map } ". The first " { $snippet "n" } " items after the quotation will be "
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"passed to the quotation given to map-withn for each element in the sequence."
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}
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{ $examples
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{ $example "USING: math sequences.lib prettyprint ;" "1 2 3 4 { 6 7 8 9 10 } [ + + + + ] 4 map-withn .s" "{ 16 17 18 19 20 }" }
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}
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{ $see-also each-withn } ;
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HELP: each-withn
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{ $values { "seq" sequence } { "quot" quotation } { "n" number } }
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{ $description "A generalisation of " { $link each } ". The first " { $snippet "n" } " items after the quotation will be "
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"passed to the quotation given to each-withn for each element in the sequence."
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}
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{ $see-also map-withn } ;
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HELP: if-seq
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{ $values { "seq" sequence } { "quot1" quotation } { "quot2" quotation } }
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{ $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." }
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{ $example
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"USING: kernel prettyprint sequences sequences.lib ;"
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"{ 1 2 3 } [ sum ] [ \"empty sequence\" throw ] if-seq ."
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"6"
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} ;
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HELP: if-empty
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{ $values { "seq" sequence } { "quot1" quotation } { "quot2" quotation } }
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{ $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." }
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{ $example
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"USING: kernel prettyprint sequences sequences.lib ;"
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"{ 1 2 3 } [ \"empty sequence\" ] [ sum ] if-empty ."
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"6"
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} ;
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{ if-seq if-empty } related-words
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