June 2018 Update

Task/Flatten-a-list/Aime/flatten-a-list.aime

@@ -1,52 +1,34 @@
 void
 show_list(list l)
 {
-    integer i;
-    text s;
+    integer i, k;
 
     o_text("[");
 
-    s = "";
-
     i = 0;
-    while (i < l_length(l)) {
-        o_text(s);
-        if (l_s_integer(l, i)) {
-            o_integer(l[i]);
+    while (i < ~l) {
+        o_text(i ? ", " : "");
+        if (l_j_integer(k, l, i)) {
+            o_integer(k);
         } else {
             show_list(l[i]);
         }
-        s = ", ";
         i += 1;
     }
 
     o_text("]");
 }
 
-void
-flat(list c, object o)
+list
+flatten(list c, object o)
 {
     if (__id(o) == INTEGER_ID) {
-        l_append(c, o);
+        c.append(o);
     } else {
-        l_ucall(o, flat, 1, c);
+        l_ucall(o, flatten, 1, c);
     }
-}
 
-list
-flatten(list l)
-{
-    list c;
-
-    l_ucall(l, flat, 1, c);
-
-    return c;
-}
-
-list
-nl(...)
-{
-    return xcall(l_assemble);
+    c;
 }
 
 integer
@@ -54,12 +36,13 @@ main(void)
 {
     list l;
 
-    l = nl(nl(1), 2, nl(nl(3, 4), 5), nl(nl(nl())), nl(nl(nl(6))), 7, 8, nl());
+    l = list(list(1), 2, list(list(3, 4), 5),
+             list(list(list())), list(list(list(6))), 7, 8, list());
 
     show_list(l);
     o_byte('\n');
 
-    show_list(flatten(l));
+    show_list(flatten(list(), l));
     o_byte('\n');
 
     return 0;

Task/Flatten-a-list/JavaScript/flatten-a-list-5.js

@@ -1,3 +1,2 @@
-let flatten = list => list.reduce(
-    (a, b) => a.concat(Array.isArray(b) ? flatten(b) : b), []
-);
+// flatten :: Tree a -> [a]
+const flatten = t => Array.isArray(t) ? [].concat(...t.map(flatten)) : t;

Task/Flatten-a-list/Julia/flatten-a-list-1.julia

@@ -1 +1 @@
-flat(A) = mapreduce(x->isa(x,Array)? flat(x): x, vcat, [], A)
+flat(arr::Array) = mapreduce(x -> isa(x, Array) ? flat(x) : x, append!, [], arr)

Task/Flatten-a-list/Julia/flatten-a-list-2.julia

@@ -1,8 +1,11 @@
-function flat(A)
-   result = Any[]
-   grep(a) = for x in a
-               isa(x,Array) ? grep(x) : push!(result,x)
-             end
-   grep(A)
-   result
- end
+function flat2(arr)
+    rst = Any[]
+    grep(v) = for x in v
+        if isa(x, Array) grep(x) else push!(rst, x) end
+    end
+    grep(arr)
+    rst
+end
+
+arr = [[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]
+@show flat(arr)

Task/Flatten-a-list/Perl-6/flatten-a-list.pl6

@@ -0,0 +1,7 @@
+my @l = [[1], 2, [[3,4], 5], [[[]]], [[[6]]], 7, 8, []];
+
+say .perl given gather @l.deepmap(*.take); # lazy recursive version
+
+# Another way to do it is with a recursive function (here actually a Block calling itself with the &?BLOCK dynamic variable):
+
+say { |(@$_ > 1 ?? map(&?BLOCK, @$_) !! $_) }(@l)

Task/Flatten-a-list/Red/flatten-a-list.red

@@ -4,3 +4,11 @@ flatten: function [
 ][
     load form block
 ]
+
+red>> flatten [[1] 2 [[3 4] 5] [[[]]] [[[6]]] 7 8 []]
+== [1 2 3 4 5 6 7 8]
+
+;flatten a list to a string
+>> blk: [1 2 ["test"] "a" [["bb"]] 3 4 [[[99]]]]
+>> form blk
+== "1 2 test a bb 3 4 99"

Task/Flatten-a-list/Ring/flatten-a-list.ring

@@ -1,10 +1,11 @@
-aList = "[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]"
-bList = ""
-cList = ""
-for n=1 to len(aList)
-    if ascii(aList[n]) >= 48 and  ascii(aList[n]) <= 57
-    bList = bList + ", " + aList[n] ok
+aString = "[[1], 2, [[3, 4], 5], [[[]]], [[[6]]], 7, 8, []]"
+bString = ""
+cString = ""
+for n=1 to len(aString)
+    if ascii(aString[n]) >= 48 and  ascii(aString[n]) <= 57
+       bString = bString + ", " + aString[n]
+    ok
 next
-cList = substr(bList,3,Len(bList)-2)
-dList = "[" + cList + "]"
-see dList + nl
+cString = substr(bString,3,Len(bString)-2)
+cString = '"' + cString + '"'
+see cString + nl