string from a char

[Chotu S]

I know how to make a string from a given char , but I need to know how to do it in ATS without using C snippets.

Say I have function make_string that takes a char and return a string :

fun make_string (c : char) : string

This function return empty string when c = 0

Example : make_string ('a') => "a"

                make_string ('\0') => ""

In particular I want to make use of  "string_sing" inside the function.

I am unable to compile the above function even when I take '\0' into account.

Thanks

[Brandon Barker]

Could you include your code? I'm not sure what is meant by your last statement about '\0'.

Brandon Barker
brandon...@gmail.com

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[Chotu S]

I meant something like this :

fun make_string (c : char) : string =
  if c = '\0' then ""
  else strnptr2string (string_sing (c))

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[gmhwxi]

string_sing can only be applied to a non-zero char:

fun make_string (c: char) = let
  val c = g1ofg0 (c)
in
  if iseqz (c) then "" else strnptr2string(string_sing(c))
end

[Chotu S]

So main problem was forgetting to convert type  to dependent type  i.e char to char (c) .

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[Chotu S]

Now the code passes the type checker , but unfortunately I am still getting compiler errors.

implement main0 () = {

  val c = '\0'

  val s = make_string (c)
}

this does not compile and give me an error (I used to get this kind of error a lot , but have forgotten how I fixed it before , may be something to do with size or template )

Thanks

On Wed, Jul 2, 2014 at 6:47 PM, gmhwxi <gmh...@gmail.com> wrote:

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[gmhwxi]

Did you have the following line at the top:

#include "share/atspre_staload.hats"

[gmhwxi]

I noted that string_sing was not implemented. I just fixed it.

implement
{}(*tmp*)
string_sing (c) = let
  val (pfat, pfgc | p) = malloc_gc (i2sz(2))
  val ((*void*)) = $UN.ptr0_set<char> (p, c)
  val ((*void*)) = $UN.ptr0_set_at<char> (p, 1, '\000')
in
  $UN.castvwtp0{strnptr(1)}((pfat, pfgc | p))
end // end of [string_sing]

[Chotu S]

Great , thanks for fixing it , I'll  update my copy soon.

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