Pipeline-oriented programming - Scott Wlaschin - NDC Porto 2023 (F#)

 factor

    
USING: kernel math ;
IN: pipeline-demo.calc

: add1 ( x -- x' ) 1 + ;
: square ( x -- x' ) dup * ;
: double ( x -- x' ) 2 * ;

: demo1 ( -- n )
  5
  add1
  square
  double
;

: add ( x y -- n ) + ;
: times ( x y -- n ) * ;

: demo2 ( -- n )
  5
  1 add
  2 times
;

  

 factor

    
USING: math sequences sequences.extras ;
IN: pipeline-demo.collection

: pipeline ( seq -- n )
  [ 2 + ]
  [ 3 > ] map-filter
  length
;

  

 factor

    
USING: io kernel math.functions math.parser ranges sequences ;
IN: pipeline-demo.fizzbuzz

: (fizz-buzz) ( i -- str )
  dup [ 3 divisor? ] [ 5 divisor? ] bi
  2dup or [
    [ "Fizz" "" ? ] [ "Buzz" "" ? ] bi*
    append
    nip
  ] [ 2drop number>string ] if
;

: fizz-buzz ( -- )
  35 [1..b]
  [ (fizz-buzz) ] map
  "," join
  print
;

  

 factor

    
USING: accessors kernel math strings ;
IN: pipeline-demo.person

TUPLE: Person
  { Name string read-only }
  { Email string read-only }
  { Age integer read-only }
;

: person-with-name ( person name -- person' )
  swap [ Email>> ] [ Age>> ] bi Person boa
;

: person-with-email ( person email -- person' )
  swap [ Name>> ] [ Age>> ] bi swapd Person boa
;

: person-with-age ( person age -- person' )
  swap [ Name>> ] [ Email>> ] bi rot Person boa
;

: demo ( -- person )
  "Scott" "s@example.com" 21 Person boa
  "Tom" person-with-name
  "tom@example.com" person-with-email
  42 person-with-age
;

  

 factor

    
USING: sequences splitting strings ;
IN: pipeline-demo.roman

: >roman-numerals ( n -- str )
  CHAR: I 
  "IIIII" "V" replace
  "VV" "X" replace
  "XXXXX" "L" replace
  "LL" "C" replace
  ! special cases:
  "VIIII" "IX" replace
  "IIII" "IV" replace
  "LXXXX" "XC" replace
  "XXXX" "XL" replace
;

: >roman-numerals-alt ( n -- str )
  CHAR: I 
  {
    { "IIIII" "V" }
    { "VV" "X" }
    { "XXXXX" "L" }
    { "LL" "C" }
    ! special cases:
    { "VIIII" "IX" }
    { "IIII" "IV" }
    { "LXXXX" "XC" }
    { "XXXX" "XL" }
  } [ first2 replace ] each
;