HOFs test

hofs.rye.red

;
; # Rye HOFs demo
;
numbers: { 1 2 3 4 }
;
; map
;
numbers |map { + 100 } |prn                          ; add 100 to all numbers
numbers |map { .factor-of 2 } |prn                   ; turn to 1 if even and 0 otherwise
numbers |map { :x , x * x } |prn                     ; run to it's squares
numbers |map ?inc |prn                               ; return all incremented by 1
;
; filter & seek
;
even: factor-of _ 2                                  ; experimental partial application
numbers |filter { > 2 }                              ; return values greater than 3
numbers |filter ?even                                ; return just even values
numbers |seek { :x all { x > 2  even x } }           ; find first greater than 2 and even
;
; reduce & fold
;
numbers |reduce 'acc { * acc }                       ; factorial of 4
numbers |reduce 'acc { .str + acc }                  ; reverse to string
numbers |fold 'acc 0 { .even .either { inc acc } { acc } } ; count even numbers
numbers |fold 'acc { } { :x , acc + eval { x x } }   ; double values 
:doubles |print                                      ; save to doubles
;
; partition
;
doubles |partition { , } |print                      ; partition same together
doubles |partition { > 2 } |print                    ; partition same together
;
; group
;
numbers |group { .even .str } |print
{ { 100 "Jim" } { 30 "Matt" } { 70 "Zoe" } } :players 
|group { .first > 50 |either { "pass" } { "fail" } } 
|print