Monads/List monad: Difference between revisions
→{{header|C}}
Line 141:
{{Out}}
<syntaxhighlight lang="applescript">{{3, 4, 5}, {5, 12, 13}, {6, 8, 10}, {7, 24, 25}, {8, 15, 17}, {9, 12, 15}, {12, 16, 20}, {15, 20, 25}}</syntaxhighlight>
=={{header|ATS}}==
<syntaxhighlight lang="ats">
#include "share/atspre_staload.hats"
(* I will use the list type of prelude/SATS/list.sats *)
#define NIL list_nil ()
#define :: list_cons
fn {a : t@ype}
unit_List (x : a) : list (a, 1) =
x :: NIL
fn {a, b : t@ype}
bind_List (m : List a,
f : a -<cloref1> List b) : List0 b =
let
fun
reversed_segments (m : List a,
accum : List0 (List b))
: List0 (List b) =
case+ m of
| NIL => accum
| hd :: tl => reversed_segments (tl, f hd :: accum)
fun
assemble_segments (segments : List (List b),
accum : List0 b)
: List0 b =
case+ segments of
| NIL => accum
| hd :: tl =>
let
prval () = lemma_list_param hd
val accum = list_append (hd, accum)
in
assemble_segments (tl, accum)
end
in
assemble_segments (reversed_segments (m, NIL), NIL)
end
infixl 0 >>=
overload >>= with bind_List
fn
intseq_List {n : nat}
(i0 : int,
n : int n) :<cloref1> list (int, n) =
let
implement
list_tabulate$fopr<int> j = i0 + j
in
list_vt2t (list_tabulate<int> n)
end
implement
main0 () =
let
val n = 25
val pythagorean_triples =
intseq_List (1, n) >>=
(lam i =>
(intseq_List (succ (i : int), n) >>=
(lam j =>
(intseq_List (succ (j : int), n) >>=
(lam k =>
let
val i = i : int
and j = j : int
and k = k : int
in
if (i * i) + (j * j) = (k * k) then
@(i, j, k) :: NIL
else
NIL
end)))))
fun
loop {n : nat}
.<n>.
(m : list (@(int, int, int), n)) : void =
case+ m of
| NIL => ()
| (@(a, b, c) :: tl) =>
begin
println! ("(", a, ",", b, ",", c, ")");
loop tl
end
in
loop pythagorean_triples
end
</syntaxhighlight>
{{out}}
We should get a list of Pythagorean triples that start with some integer between 1 and 25, inclusive.
<pre>$ patscc -std=gnu2x -g -O2 -DATS_MEMALLOC_GCBDW list_monad_ats.dats -lgc && ./a.out
(3,4,5)
(5,12,13)
(6,8,10)
(7,24,25)
(8,15,17)
(9,12,15)
(10,24,26)
(12,16,20)
(12,35,37)
(15,20,25)
(15,36,39)
(16,30,34)
(18,24,30)
(20,21,29)
(21,28,35)
(24,32,40)
(24,45,51)
</pre>
=={{header|C}}==
Line 182 ⟶ 301:
<syntaxhighlight lang="bash">$ ./monad
13</syntaxhighlight>
=={{header|C++}}==
| |||