Voldemort toHexString Compile Error

Mar 17

Salih Dincer

Mar 17

Richard (Rikki) Andrew Cattermole

Mar 17

kdevel

Mar 17

Richard (Rikki) Andrew Cattermole

Mar 17

kdevel

Mar 18

Salih Dincer

March 17

Voldemort toHexString Compile Error

Posted by Salih Dincer

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Salih Dincer

Permalink

void main()
{
  import std.stdio;

  "Hello D".toHexString.writeln;
}

struct HexString
{
  int i;

  auto nibbleSplit()
  {
    auto MSB = i >> 4;
    auto LSB = i & 15;
    return [MSB, LSB];
  }
}

auto toHexString(string str)
{
  struct Hex { int i;
    auto nibbleSplit() {
      auto MSB = i >> 4;
      auto LSB = i & 15;
      return [MSB, LSB];
    }
  }

  import std.algorithm : map;
  import std.conv, std.range : join;

  return str.map!Hex//String
            .map!(e => e.nibbleSplit).join
            .map!(n => n += n > 9 ? '7' : '0')
            .map!(c => c.to!char);
}

Why doesn't the function compile? But the code is compiled with the HexString structure. The error given by the compiler is as follows:

/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(582): Error: cannot access frame pointer of onlineapp.toHexString.Hex
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(479): Error: template instance std.algorithm.iteration.MapResult!(Hex, string) error instantiating
onlineapp.d(33): instantiated from here: map!string
onlineapp.d(34): Error: template onlineapp.toHexString.map!((e) => e.nibbleSplit).map is not callable using argument types !()(MapResult!(Hex, string))
/dlang/dmd/linux/bin64/../../src/phobos/std/algorithm/iteration.d(446): Candidate is: map(Range)(Range r)
with Range = MapResult!(Hex, string)
must satisfy the following constraint:
` isInputRange!(Unqual!Range)

On Sunday, 17 March 2024 at 13:08:14 UTC, Richard (Rikki) Andrew Cattermole wrote: > It is because Hex is nested, it has an outer pointer to the call frame of toHexString. > > Make Hex static, and it works. Not really. Have you ever tried? "abc äöüß€ D".toHexString.writeln;

On 18/03/2024 5:45 AM, kdevel wrote: > On Sunday, 17 March 2024 at 13:08:14 UTC, Richard (Rikki) Andrew Cattermole wrote: >> It is because Hex is nested, it has an outer pointer to the call frame of toHexString. >> >> Make Hex static, and it works. > > Not really. Have you ever tried? > > "abc äöüß€ D".toHexString.writeln; > I did run it, both with and without static on Hex. Without did not work on run.dlang.io which was consistent with the error that Salih had provided. The error is clear on the first line: "cannot access frame pointer of onlineapp.toHexString.Hex"

On Sunday, 17 March 2024 at 16:48:23 UTC, Richard (Rikki) Andrew Cattermole wrote: > [...] >>> Make Hex static, and it works. >> >> Not really. Have you ever tried? >> >> "abc äöüß€ D".toHexString.writeln; >> > > I did run it, both with and without static on Hex. > > Without did not work on run.dlang.io which was consistent with the error that Salih had provided. > > The error is clear on the first line: "cannot access frame pointer of onlineapp.toHexString.Hex" I meant the compiled executable, not the compilation. The code has an autodecoding issue which goes unnoticed due to using int (instead of ubyte?) for i. When I run the executable I get a three screens stack trace. std.conv.ConvOverflowException@[...]linux/bin64/../../src/phobos/std/conv.d(1556): Conversion positive overflow BTW: What is the purpose of not writing a free function like this?: auto nibbleSplit(ubyte b) { auto MSB = b >> 4; auto LSB = b & 15; return [MSB, LSB]; } auto toHexString(string str) { import std.algorithm : map; import std.conv, std.range : join; import std.utf; return str // .byCodeUnit // <-- solves the auto-decoding issue .map!(e => e.nibbleSplit).join .map!(n => n += n > 9 ? '7' : '0') .map!(c => c.to!char); }

auto toHexRange(T)(const char[] str) { static struct HexRange { int i; auto nibbleSplit() { auto MSB = i >> 4; auto LSB = i & 15; return [MSB, LSB]; } } import std.utf : byCodeUnit; import std.algorithm : map; import std.range : join; return str.byCodeUnit.map!HexRange .map!(e => e.nibbleSplit).join .map!(n => n += n > 9 ? '7' : '0') .map!(c => c.to!T); } auto toHex(T)(const char[] str) { static if(is(T : string)) { import std.algorithm : copy; auto result = new char[str.length * 2]; str.toHexRange!char.copy(result); return cast(string)result; } else { import std.array; return str.toHexRange!T.array; } } unittest { enum Expected = "61626320C3A4C3B6C3BC50C39FE282AC207B447D"; enum str = "abc äöüPß€ {D}"; assert(str.toHex!string == Expected); import std.conv : hexString; static assert(hexString!Expected == str); enum NATO { Alpha = '0', Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo = 'A', Lima, Mike, November, Oscar, Papa } auto test = str.toHex!NATO; assert(is(typeof(test) : NATO[])); }

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