Add some list functions.

[puripuri2100]

functions

• head : 'a list -> 'a option
• tail : 'a list -> ('a list) option
• reverse-append : 'a list -> 'a list -> 'a list
• reverse-map : ('a -> 'b) -> 'a list -> 'b list
• for-all : ('a -> bool) -> 'a list -> bool
• exists : ('a -> bool) -> 'a list -> bool
• for-all2 : ('a -> 'b -> bool) -> 'a list -> 'b list -> bool option
• exists2 : ('a -> 'b -> bool) -> 'a list -> 'b list -> bool option
• find : ('a -> bool) -> 'a list -> 'a option
• partition : ('a -> bool) -> 'a list -> 'a list * 'a list
• split : ('a * 'b) list -> 'a list * 'b list
• combine : 'a list -> 'b list -> (('a * 'b) list) option

reference

• Module List

[puripuri2100]

• last : 'a list -> 'a option

  last [] %==> None
  last [1] %==> Some(1)
  last [1;2;3;4] %==> Some(4)
  

• init : 'a list -> ('a list) option

  init [] %==> None
  init [1] %==> Some([])
  init [1;2;3;4] %==> Some([1;2;3])
  

• take : int -> 'a list -> 'a list

  take 2 [] %==> []
  take 2 [1] %==> [1]
  take 2 [1;2;3;4] %==> [1;2;3]
  take 0 [] %==> []
  take 0 [1] %==> [1]
  take 0 [1;2;3;4] %==> [1]
  take (-1) [] %==> []
  take (-1) [1] %==> []
  take (-1) [1;2;3;4] %==> []
  

• drop : int -> 'a list -> 'a list

  drop 2 [] %==> []
  drop 2 [1] %==> []
  drop 2 [1;2;3;4] %==> [4]
  drop 0 [] %==> []
  drop 0 [1] %==> []
  drop 0 [1;2;3;4] %==> [2;3;4]
  drop (-1) [] %==> []
  drop (-1) [1] %==> [1]
  drop (-1) [1;2;3;4] %==> [1;2;3;4]
  

• bubblesort : ('a -> 'a -> int) -> 'a list -> 'a list

  let f n m =
    if n < m then
        -1
      else
        if n > m then
          1
        else
          0
  in
  
  bubblesort f [] %==> []
  bubblesort f [1] %==> [1]
  bubblesort f [1;2;3;4] %==> [1;2;3;4]
  bubblesort f [4;3;2;1] %==> [1;2;3;4]
  bubblesort f [2;4;3;1] %==> [1;2;3;4]
  bubblesort f [1;2;3;4;3;3] %==> [1;2;3;3;3;4]
  

[puripuri2100]

• apply : 'a -> ('a -> 'b) list -> 'b list

  let f2 n m = n + m in
  apply 5 [f2 1; f2 2; f2 3] % ==>[6; 7; 8]
  

• show-opt : ('a option) list -> 'a list

  show-opt [Some(1); Some(2); None; Some(4);] %==>[1;2;4]
  show-opt [None; None;] %==> []
  

• iterate : int -> ('a -> 'a) -> 'a -> 'a list

  iterate 5 (fun n -> n + 1) 2 %==>[3; 4; 5; 6; 7]
  iterate 0 (fun n -> n + 1) 2 %==> []
  

• repeat : int -> 'a -> 'a list

  repeat 5 2 %==>[2;2;2;2;2]
  

• make-cycle : int -> 'a list -> 'a list

  2 [1;3;2] %==> [1;3;2;1;3;2]
  

• takewhile : ('a -> bool) -> 'a list -> 'a list

  takewhile (fun x -> x < 4) [1;2;3;4;5] %==> [1; 2; 3]
  

• dropwhile : ('a -> bool) -> 'a list -> 'a list

  dropwhile (fun x -> x < 4) [1;2;3;4;5] %==> [4;5]
  

• splitat : int -> 'a list -> ('a list * 'a list)

  splitat 2 [1;2;3;4;5] %==>([1; 2; 3], [4; 5])
  

• span : ('a -> bool) -> 'a list -> ('a list * 'a list)

  span (fun x -> x < 3) [1;2;3;4;5] %==>([1;2], [3;4;5])
  

• break : ('a -> bool) -> 'a list -> ('a list * 'a list)

  break (fun x -> x > 3) [1;2;3;4;5] %==> ([1;2;3], [4;5])
  

[puripuri2100]

That's all.
I would appreciate it if you could merge this PR. @gfngfn

[nyuichi]

@puripuri2100

Hi, I love this patch. I'd like to use your functions in my personal project soon, and can I (or perhaps can you) import this also to list2.satyh at satysfi-lib?

[puripuri2100]

This change has already imported in satysfi-base.
Should I close this pull request? 🤔
@gfngfn