I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.

That said: if people think this is a decent collection, and Walter would take it, I would be willing to release it to public domain for Phobos' sake.

The array module is attached, and the docs are at: http://www.codemeu.com:81/~pontiff/projects/cashew/doc/array.html

-- Christopher Nicholson-Sauls

And just a few minutes later, I issue another release...  I'd neglected a little something from rotl() and rotr(), namely I hadn't accounted for iterations greater than the array's length.  Heh.  Fixed now.  New version attached.

-- Chris Nicholson-Sauls

Chris Nicholson-Sauls wrote:
> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.


Nice.. I hope something like this will make it into Phobos at some point, since everybody seems to have implemented these functions anyway..

One remark though: your removeAll is pretty slow. It should be enough to iterate the array only once. A indexOf that takes a starting_index would be a simple fix.

L.

Lionello Lunesu wrote:
> Chris Nicholson-Sauls wrote:
> 
>> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.
> 
> 
> 
> Nice.. I hope something like this will make it into Phobos at some point, since everybody seems to have implemented these functions anyway..
> 
> One remark though: your removeAll is pretty slow. It should be enough to iterate the array only once. A indexOf that takes a starting_index would be a simple fix.
> 
> L.

True... and fixed.  :)  Functions indexOf, rindexOf, indexOfSub, and rindexOfSub all take an optional 'start' parameter now.  This effected the design of functions removeAll and unique.

I did, however, have to do something weird with removeAll.  It just didn't want to work right any other way... must play with it some more later.

-- Chris Nicholson-Sauls

Chris Nicholson-Sauls wrote:
> Lionello Lunesu wrote:
>> Chris Nicholson-Sauls wrote:
>>
>>> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.
>>
>>
>>
>> Nice.. I hope something like this will make it into Phobos at some point, since everybody seems to have implemented these functions anyway..
>>
>> One remark though: your removeAll is pretty slow. It should be enough to iterate the array only once. A indexOf that takes a starting_index would be a simple fix.
>>
>> L.
> 
> True... and fixed.  :)  Functions indexOf, rindexOf, indexOfSub, and rindexOfSub all take an optional 'start' parameter now.  This effected the design of functions removeAll and unique.
> 
> I did, however, have to do something weird with removeAll.  It just didn't want to work right any other way... must play with it some more later.
> 
> -- Chris Nicholson-Sauls
> 
> 
> ------------------------------------------------------------------------
> 
> /*****************************************************************************************
>  * Utility template functions for arrays.  Example:
>  *
>  * $(CASHEW_HEAD)
>  *----------------------------------------------------------------------------------------
>  * import cashew .utils .array ;
>  * // ...
>  * int[] foo = ...;
>  * foo.remove(4);
>  * foo.eat(foo.indexOf(2));
>  *----------------------------------------------------------------------------------------
>  */
> module cashew.utils.array ;
> 
> /***********************************************************************************
>  * Unit tests support.
>  */
> version (Unittest) {
>   import std .stdio ;
> }
> 
> unittest {
>   writefln("Unittest: cashew.utils.array: begin");
> }
> 
> /***********************************************************************************
>  * Create an array.
>  */
> T[] array (T) (T[] arr ...)
> body {
>   return arr.dup;
> }
> unittest {
>   writef("\t array(...) --------> ");
>   auto foo = array!(int)(1, 2, 3);
>   assert(foo.length == 3U);
>   assert(typeid(typeof(foo[0])) == typeid(typeof(1)));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Verify that a given value is present in an array.
>  */
> bool contains (T) (inout T[] haystack, T needle)
> body {
>   return haystack.indexOf(needle) != size_t.max;
> }
> unittest {
>   writef("\t.contains(T) -------> ");
>   auto foo = array!(int)(1, 2, 3);
>   assert(  foo.contains(2));
>   assert(! foo.contains(4));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Compose a new array of the values in the first parameter not present in the second.
>  */
> T[] diff (T) (inout T[] alpha, inout T[] beta)
> body {
>   T[] result = alpha.dup;
> 
>   foreach (x; alpha) {
>     if (beta.contains(x)) {
>       while (result.contains(x)) {
>         result.remove(x);
>       }
>     }
>   }
>   return result;
> }
> unittest {
>   writef("\t.diff(T[]) ---------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto bar = array!(int)(1,    3,    5);
>   assert(foo.diff(bar) == array!(int)(2, 4));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Remove some of the beginning of an array.
>  */
> void eat (T) (inout T[] haystack, size_t count)
> body {
>   if (count > haystack.length) {
>     haystack.length = 0;
>   }
>   else {
>     haystack = haystack[count .. haystack.length];
>   }
> }
> unittest {
>   writef("\t.eat(N) ------------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   foo.eat(3U);
>   assert(foo == array!(int)(4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Search an array for a given item, and return its index, or size_t.max if not found.
>  */
> size_t indexOf (T) (inout T[] haystack, T needle, size_t start = 0U)
> body {
>   size_t result = size_t.max ;
> 
>   foreach (index, item; haystack[start .. haystack.length]) {
>     if (item is needle) {
>       result = index;
>       break;
>     }
>   }
>   if (result != size_t.max) {
>     result += start;
>   }
>   return result;
> }
> unittest {
>   writef("\t.indexOf(T) --------> ");
>   auto foo = array!(int)(1, 2, 3);
>   assert(foo.indexOf(2) == 1U);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Search an array for a given sub-array, and return its index, or size_t.max if not found.
>  */
> size_t indexOfSub (T) (inout T[] haystack, inout T[] bale, size_t start = 0U)
> body {
>   size_t result = size_t.max                    ,
>          wall   = haystack.length - bale.length ;
> 
>   for (size_t i = start; i < wall; i++) {
>     if (haystack[i .. i + bale.length] == bale) {
>       result = i;
>       break;
>     }
>   }
>   return result;
> }
> unittest {
>   writef("\t.indexOfSub(T[]) ---> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto sub = array!(int)(      3, 4   );
>   assert(foo.indexOfSub(sub) == 2U);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Same as indexOf but work backwards from the end.
>  */
> size_t rindexOf (T) (inout T[] haystack, T needle, size_t start = size_t.max)
> body {
>   size_t result = size_t.max ;
> 
>   if (start == size_t.max) {
>     start = haystack.length - 1U;
>   }
>   for (size_t i = start; i >= 0U; i--) {
>     if (haystack[i] is needle) {
>       result = i;
>       break;
>     }
>   }
>   return result;
> }
> unittest {
>   writef("\t.rindexOf(T) -------> ");
>   auto foo = array!(int)(1, 9, 2, 9, 3);
>   assert(foo.rindexOf(9) == 3U);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Same as indexOf but work backwards from the end.
>  */
> size_t rindexOfSub (T) (inout T[] haystack, inout T[] bale, size_t start = size_t.max)
> body {
>   size_t result = size_t.max ;
> 
>   if (start == size_t.max) {
>     start = haystack.length;
>   }
>   for (size_t i = start - bale.length; i >= 0; i--) {
>     if (haystack[i .. i + bale.length] == bale) {
>       result = i;
>       break;
>     }
>   }
>   return result;
> }
> unittest {
>   writef("\t.rindexOfSub(T[]) --> ");
>   auto foo = array!(int)(1, 2, 9, 8, 1, 2, 9, 8);
>   auto sub = array!(int)(1, 2                  );
>   assert(foo.rindexOfSub(sub) == 4U);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Return an array composed of common elements of two arrays.
>  */
> T[] intersect (T) (inout T[] alpha, inout T[] beta)
> body {
>   T[] result;
> 
>   foreach (x; alpha) {
>     if (beta.contains(x)) {
>       result ~= x;
>     }
>   }
>   return result;
> }
> unittest {
>   writef("\t.intersect(T[]) ----> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5      );
>   auto bar = array!(int)(      3, 4, 5, 6, 7);
>   assert(foo.intersect(bar) == array!(int)(3, 4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Remove an item from an array.
>  */
> void remove (T) (inout T[] haystack, T needle)
> body {
>   size_t index = haystack.indexOf(needle) ;
> 
>   if (index != size_t.max) {
>     haystack.removeIndex(index);
>   }
> }
> unittest {
>   writef("\t.remove(T) ---------> ");
>   auto foo = array!(int)(1, 2, 3);
>   foo.remove(2);
>   assert(foo == array!(int)(1, 3));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Remove all occurances of an item from an array.
>  */
> void removeAll (T) (inout T[] haystack, T needle)
> body {
>   size_t   index   = 0U ;
>   size_t[] indices      ;
> 
>   while ((index = haystack.indexOf(needle, index)) != size_t.max) {
>     indices ~= index;
>     index++;
>   }
>   foreach (i, x; indices) {
>     haystack.removeIndex(x - i);
>   }
> }
> unittest {
>   writef("\t.removeAll(T) ------> ");
>   auto foo = array!(int)(1, 2, 1, 3, 1, 4, 1, 5);
>   foo.removeAll(1);
>   assert(foo == array!(int)(2, 3, 4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Remove the item at a given index.
>  */
> void removeIndex (T) (inout T[] haystack, size_t index)
> body {
>   haystack = haystack[0 .. index] ~ haystack[index + 1 .. haystack.length];
> }
> unittest {
>   writef("\t.removeIndex(N) ----> ");
>   auto foo = array!(int)(1, 2, 3, 4);
>   foo.removeIndex(2U);
>   assert(foo == array!(int)(1, 2, 4));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Build an array by repeating an item.
>  */
> void repeat (T) (inout T[] haystack, T needle, size_t len = size_t.max)
> body {
>   if (len == size_t.max) {
>     len = haystack.length;
>   }
> 
>   haystack.length = len;
>   haystack[] = needle;
> }
> unittest {
>   writef("\t.repeat(T [, N]) ---> ");
>   int[] foo ;
>   foo.repeat(3, 3U);
>   assert(foo == array!(int)(3, 3, 3));
> 
>   auto bar = array!(int)(0, 0, 0, 0, 0, 0, 0);
>   bar.repeat(7);
>   assert(bar == array!(int)(7, 7, 7, 7, 7, 7, 7));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Build an array by repeating a smaller array.
>  */
> void repeatSub (T) (inout T[] haystack, inout T[] bale, size_t count)
> body {
>   haystack.length = 0;
>   for (int i; i < count; i++) {
>     haystack ~= bale;
>   }
> }
> unittest {
>   writef("\t.repeatSub(T[], N) -> ");
>   int[] foo                     ,
>         sub = array!(int)(4, 2) ;
>   foo.repeatSub(sub, 3U);
>   assert(foo == array!(int)(4, 2, 4, 2, 4, 2));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Fill an array with a given smaller array.
>  */
> void fill (T) (inout T[] haystack, inout T[] bale, size_t len = size_t.max)
> body {
>   if (len == size_t.max) {
>     len = haystack.length;
>   }
>   haystack.length = 0;
>   while (haystack.length < len) {
>     haystack ~= bale;
>   }
>   haystack.length = len;
> }
> unittest {
>   writef("\t.fill (T[] [, N]) --> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto sub = array!(int)(3, 2, 1      );
>   foo.fill(sub);
>   assert(foo == array!(int)(3, 2, 1, 3, 2));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Remove duplicate values from an array.
>  */
> void unique (T) (inout T[] haystack)
> body {
>   size_t ridx ;
> 
>   for (int i = 0; i < haystack.length; i++) {
>     ridx = size_t.max;
>     while ((ridx = haystack.rindexOf(haystack[i], ridx)) != i) {
>       haystack.removeIndex(ridx);
>     }
>   }
> }
> unittest {
>   writef("\t.unique() ----------> ");
>   auto foo = array!(int)(1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5);
>   foo.unique();
>   assert(foo == array!(int)(1, 2, 3, 4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Pull a number of items from one array into another.
>  */
> T[] pull (T) (inout T[] haystack, size_t idx)
> body {
>   T[] result ;
> 
>   if (idx >= haystack.length) {
>     idx = haystack.length;
>   }
> 
>   result   = haystack[0   .. idx            ];
>   haystack = haystack[idx .. haystack.length];
>   return result;
> }
> unittest {
>   writef("\t.pull(N) -----------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto bar = foo.pull(3U);
>   assert(foo == array!(int)(         4, 5));
>   assert(bar == array!(int)(1, 2, 3      ));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Same as pull, but indexed from the end.
>  */
> T[] rpull (T) (inout T[] haystack, size_t idx)
> body {
>   T[] result ;
> 
>   if (idx >= haystack.length) {
>     result = haystack;
>     haystack.length = 0;
>   }
>   else {
>     idx--;
> 
>     result   = haystack[idx .. haystack.length];
>     haystack = haystack[0   .. idx            ];
>   }
>   return result;
> }
> unittest {
>   writef("\t.rpull(N) ----------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto bar = foo.rpull(3U);
>   assert(foo == array!(int)(1, 2         ));
>   assert(bar == array!(int)(      3, 4, 5));
> 
>   auto alpha = array!(int)(1, 2, 3);
>   auto beta  = alpha.rpull(4U);
>   assert(alpha == array!(int)(       ));
>   assert(beta  == array!(int)(1, 2, 3));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Rotate an array's contents toward the left.
>  */
> void rotl (T) (inout T[] haystack, size_t iter)
> body {
>   iter %= haystack.length;
>   haystack = haystack[iter .. haystack.length] ~ haystack[0 .. iter];
> }
> unittest {
>   writef("\t.rotl(N) -----------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5, 6);
>   foo.rotl(2U);
>   assert(foo == array!(int)(3, 4, 5, 6 ,1, 2));
> 
>   auto bar = array!(int)(1, 2, 3);
>   bar.rotl(4U);
>   assert(bar == array!(int)(2, 3, 1));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Rotate an array's contents toward the right.
>  */
> void rotr (T) (inout T[] haystack, size_t iter)
> body {
>   size_t idx  ;
> 
>   iter %= haystack.length        ;
>   idx   = haystack.length - iter ;
>   haystack = haystack[idx .. haystack.length] ~ haystack[0 .. idx];
> }
> unittest {
>   writef("\t.rotr(N) -----------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5, 6);
>   foo.rotr(2U);
>   assert(foo == array!(int)(5, 6, 1, 2, 3, 4));
> 
>   auto bar = array!(int)(1, 2, 3);
>   bar.rotr(4U);
>   assert(bar == array!(int)(3, 1, 2));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Append to an array.
>  */
> void push (T) (inout T[] haystack, T[] bale ...)
> body {
>   haystack ~= bale;
> }
> unittest {
>   writef("\t.push(...) ---------> ");
>   auto foo = array!(int)(1, 2, 3);
>   foo.push(4, 5);
>   assert(foo == array!(int)(1, 2, 3, 4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Retrieve and remove the last value of an array.
>  */
> T pop (T) (inout T[] haystack)
> body {
>   T result = haystack[haystack.length - 1];
> 
>   haystack.length = haystack.length - 1;
>   return result;
> }
> unittest {
>   writef("\t.pop() -------------> ");
>   auto foo = array!(int)(1, 2, 3);
>   auto elm = foo.pop();
>   assert(foo == array!(int)(1, 2));
>   assert(elm == 3);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Prepend to an array.
>  */
> void backpush (T) (inout T[] haystack, T[] bale ...)
> body {
>   haystack ~= bale;
>   haystack.rotr(bale.length);
> }
> unittest {
>   writef("\t.backpush(...) -----> ");
>   auto foo = array!(int)(3, 4);
>   foo.backpush(1, 2);
>   assert(foo == array!(int)(1, 2, 3, 4));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Retrieve and remove the first value of an array.
>  */
> T backpop (T) (inout T[] haystack)
> body {
>   T result = haystack[0];
> 
>   haystack = haystack[1 .. haystack.length];
>   return result;
> }
> unittest {
>   writef("\t.backpop() ---------> ");
>   auto foo = array!(int)(1, 2, 3);
>   auto elm = foo.backpop();
>   assert(foo == array!(int)(2, 3));
>   assert(elm == 1);
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Drop values from the beginning of an array.
>  */
> T[] shift (T) (inout T[] haystack, size_t count)
> body {
>   T[] result ;
> 
>   if (count >= haystack.length) {
>     result = haystack;
>     haystack.length = 0;
>   }
>   else {
>     result = haystack[0 .. count];
>     haystack = haystack[count .. haystack.length];
>   }
>   return result;
> }
> unittest {
>   writef("\t.shift(N) ----------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto sub = foo.shift(3U);
>   assert(foo == array!(int)(         4, 5));
>   assert(sub == array!(int)(1, 2, 3      ));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Drop values from the end of an array.
>  */
> T[] rshift (T) (inout T[] haystack, size_t count)
> body {
>   T[] result ;
> 
>   if (count >= haystack.length) {
>     result = haystack;
>     haystack.length = 0;
>   }
>   else {
>     result = haystack[haystack.length - count .. haystack.length];
>     haystack.length = haystack.length - count;
>   }
>   return result;
> }
> unittest {
>   writef("\t.rshift(N) ---------> ");
>   auto foo = array!(int)(1, 2, 3, 4, 5);
>   auto sub = foo.rshift(3U);
>   assert(foo == array!(int)(1, 2         ));
>   assert(sub == array!(int)(      3, 4, 5));
>   writefln("Pass");
> }
> 
> /***********************************************************************************
>  * Unit tests support.
>  */
> unittest {
>   writefln("Unittest: cashew.utils.array: end\n");
> }

Phobos does need something like this.

clayasaurus wrote:
> Phobos does need something like this.

very badly, everyone rolls their own so it would be nice to have stuff like that consolidated in the community....

I also think this would give a more 'complete' feeling to the built-in arrays

On Wed, 13 Sep 2006 07:56:36 +0400, Chris Nicholson-Sauls <ibisbasenji@gmail.com> wrote:

> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I
> updated the array module in my personal Cashew lib.  Included in the updates are the
> rotl/rotr that I recall someone asking about.

Ahh, thanks!

Chris Nicholson-Sauls wrote:
> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.
> 
> That said: if people think this is a decent collection, and Walter would take it, I would be willing to release it to public domain for Phobos' sake.
> 
> The array module is attached, and the docs are at:
> http://www.codemeu.com:81/~pontiff/projects/cashew/doc/array.html
> 
> -- Christopher Nicholson-Sauls
> 
It looks good. Thanks for doing this.

Some comments/questions:

Why does indexOfSub have bale as 'inout', not simply 'in'?
Same question for fill

Couldn't indexOfSub be named indexOf?
Same question for repeatSub and repeat.

Also, thinking about its possible use as the starting point for a standard library, I've got some other thoughts for functions which are implemented in other array processing libraries (std.string, Oskar Linde's templated array functions, mintl.array...). Here is what I was thinking could be useful:

splitting/joining:
  split
  join

string processing:
  stripl/stripr/strip/chomp

string matching/replacing:
  replace
  insert
  count
  squeeze // from std.string
  startsWith
  endsWith

searching:
  findmax
  findmin
  find(delegate matches)
  findAll(delegate matches)

I've written some code:
T[][] split (T) (T[] arr, T[] delim ...)
in { assert (delim.length > 0, "Splitting with no delimiters is useless"); }
body
{
  T[][] results;
  T[] token;

  foreach (i, x; arr)
  {
    if (delim.contains(x))
	{
	  if (token.length > 0)
	  {
	     results ~= token;
		 token.length = 0;
	  }
	}
	else
	{
	  token ~= x;
	}
  }
  if (token.length > 0) results ~= token;
  return results;
}

unittest {
  writef("\t.split(...) --------> ");
/+  auto foo = "a b cde   fg";
  auto result = foo.split(' ');
  assert(result == array!(char[])("a", "b", "cde", "fg")); +/

  auto bar = "cashew casehew";
  auto result2 = bar.split('s', 'h');
  assert(result2 == array!(char[])("ca", "ew ca", "e", "ew"));
  writefln("Pass");
}

Also, couldn't you avoid the temporary in removeAll by doing this:
void removeAll (T) (inout T[] haystack, T needle)
{
  size_t index = 0U;
  size_t indices;

  while ((index = haystack.indexOf(needle, index)) != size_t.max) {
    haystack.removeIndex(index);
  }
}

If you're interested, I'll write some more code.

Cheers,

Reiner

Oh, and I forgot: a reverse iterator, like mintl.array has.

Reiner Pope wrote:
> Chris Nicholson-Sauls wrote:
> 
>> I've been pushing for some array utilities to get into Phobos, yes, but in the meantime I updated the array module in my personal Cashew lib.  Included in the updates are the rotl/rotr that I recall someone asking about.  In the process I've discovered two bugs, as well: the behavior of 'is' versus '==' is incompatable if the operands are arrays, and DDoc for abbreviated function templates is borked.  For an example of the latter, just look at Cashew's own docs.
>>
>> That said: if people think this is a decent collection, and Walter would take it, I would be willing to release it to public domain for Phobos' sake.
>>
>> The array module is attached, and the docs are at:
>> http://www.codemeu.com:81/~pontiff/projects/cashew/doc/array.html
>>
>> -- Christopher Nicholson-Sauls
>>
> It looks good. Thanks for doing this.
> 
> Some comments/questions:
> 
> Why does indexOfSub have bale as 'inout', not simply 'in'?
> Same question for fill

Because I'm mildly paranoid and wanted to avoid memory allocation where I could.  :)  I do suppose it could safely be 'in' though.

> Couldn't indexOfSub be named indexOf?
> Same question for repeatSub and repeat.

That's a D limitation.  At the moment, function templates cannot be overloaded.  *snort stomp*  Originally I /did/ have them named the same, but alas.

> Also, thinking about its possible use as the starting point for a standard library, I've got some other thoughts for functions which are implemented in other array processing libraries (std.string, Oskar Linde's templated array functions, mintl.array...). Here is what I was thinking could be useful:
> 
> splitting/joining:
>   split
>   join
> 
> string processing:
>   stripl/stripr/strip/chomp
> 
> string matching/replacing:
>   replace
>   insert
>   count
>   squeeze // from std.string
>   startsWith
>   endsWith
> 
> searching:
>   findmax
>   findmin
>   find(delegate matches)
>   findAll(delegate matches)
> 
> I've written some code:
> T[][] split (T) (T[] arr, T[] delim ...)
> in { assert (delim.length > 0, "Splitting with no delimiters is useless"); }
> body
> {
>   T[][] results;
>   T[] token;
> 
>   foreach (i, x; arr)
>   {
>     if (delim.contains(x))
>     {
>       if (token.length > 0)
>       {
>          results ~= token;
>          token.length = 0;
>       }
>     }
>     else
>     {
>       token ~= x;
>     }
>   }
>   if (token.length > 0) results ~= token;
>   return results;
> }
> 
> unittest {
>   writef("\t.split(...) --------> ");
> /+  auto foo = "a b cde   fg";
>   auto result = foo.split(' ');
>   assert(result == array!(char[])("a", "b", "cde", "fg")); +/
> 
>   auto bar = "cashew casehew";
>   auto result2 = bar.split('s', 'h');
>   assert(result2 == array!(char[])("ca", "ew ca", "e", "ew"));
>   writefln("Pass");
> }
> 
> Also, couldn't you avoid the temporary in removeAll by doing this:
> void removeAll (T) (inout T[] haystack, T needle)
> {
>   size_t index = 0U;
>   size_t indices;
> 
>   while ((index = haystack.indexOf(needle, index)) != size_t.max) {
>     haystack.removeIndex(index);
>   }
> }

That's exactly how it was written (once I'd modified .indexOf) but it doesn't act quite right for some reason.  Until I figure out what the bug is, I figured I could slap together a less pretty but working version.

> If you're interested, I'll write some more code.
> 
> Cheers,
> 
> Reiner

-- Chris Nicholson-Sauls