This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.

So far, all google searches for "dlang binary file read" end up not working for me.

Thank you.

On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>
> So far, all google searches for "dlang binary file read" end up not working for me.
>
> Thank you.

http://dpldocs.info/experimental-docs/std.file.read.1.html

import std.file : read;
auto bytes = read("filename");

This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.

On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>
>> So far, all google searches for "dlang binary file read" end up not working for me.
>>
>> Thank you.
>
> http://dpldocs.info/experimental-docs/std.file.read.1.html
>
> import std.file : read;
> auto bytes = read("filename");
>
> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.

That works great! I thought all file i/o had to through the File class.

On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>
>> So far, all google searches for "dlang binary file read" end up not working for me.
>>
>> Thank you.
>
> http://dpldocs.info/experimental-docs/std.file.read.1.html
>
> import std.file : read;
> auto bytes = read("filename");
>
> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.

Or he could do readText() which returns a string, which in turn will give a proper char array when casted.

On Monday, 3 September 2018 at 06:25:23 UTC, bauss wrote:
> On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
>> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>>
>>> So far, all google searches for "dlang binary file read" end up not working for me.
>>>
>>> Thank you.
>>
>> http://dpldocs.info/experimental-docs/std.file.read.1.html
>>
>> import std.file : read;
>> auto bytes = read("filename");
>>
>> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.
>
> Or he could do readText() which returns a string, which in turn will give a proper char array when casted.

Actually ignore the casting thing, looking at readText it takes a template parameter.

So:

char[] a = readText!(char[])("filename");

On Monday, 3 September 2018 at 06:28:38 UTC, bauss wrote:
> On Monday, 3 September 2018 at 06:25:23 UTC, bauss wrote:
>> On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
>>> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>>>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>>>
>>>> So far, all google searches for "dlang binary file read" end up not working for me.
>>>>
>>>> Thank you.
>>>
>>> http://dpldocs.info/experimental-docs/std.file.read.1.html
>>>
>>> import std.file : read;
>>> auto bytes = read("filename");
>>>
>>> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.
>>
>> Or he could do readText() which returns a string, which in turn will give a proper char array when casted.
>
> Actually ignore the casting thing, looking at readText it takes a template parameter.
>
> So:
>
> char[] a = readText!(char[])("filename");

Thanks, that works!

But... I'm so confused by D's fifty different string types.

I can run .strip() on a char[]. But I can't run .replace('\n','?') ?

So then I convert char[] to a temporary string and run replace on that.

but then writefln("%s") doesn't accept strings! Only char[].

  char []t = cast(char[])(c[i-15 .. i+1]).strip();
  string s = text(t); //s.replace('\n','?')
  writefln(" - [%s]", s); // fail

main.d(89): Error: template std.array.replace cannot deduce function from argument types !()(char[], char, char), candidates are:
/usr/include/dmd/phobos/std/array.d(2122):        std.array.replace(E, R1, R2)(E[] subject, R1 from, R2 to) if (isDynamicArray!(E[]) && isForwardRange!R1 && isForwardRange!R2 && (hasLength!R2 || isSomeString!R2))
/usr/include/dmd/phobos/std/array.d(2255):        std.array.replace(T, Range)(T[] subject, size_t from, size_t to, Range stuff) if (isInputRange!Range && (is(ElementType!Range : T) || isSomeString!(T[]) && is(ElementType!Range : dchar)))


What's going on here?

On Monday, 3 September 2018 at 07:38:51 UTC, Chris Katko wrote:
> On Monday, 3 September 2018 at 06:28:38 UTC, bauss wrote:
>> On Monday, 3 September 2018 at 06:25:23 UTC, bauss wrote:
>>> On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
>>>> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>>>>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>>>>
>>>>> So far, all google searches for "dlang binary file read" end up not working for me.
>>>>>
>>>>> Thank you.
>>>>
>>>> http://dpldocs.info/experimental-docs/std.file.read.1.html
>>>>
>>>> import std.file : read;
>>>> auto bytes = read("filename");
>>>>
>>>> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.
>>>
>>> Or he could do readText() which returns a string, which in turn will give a proper char array when casted.
>>
>> Actually ignore the casting thing, looking at readText it takes a template parameter.
>>
>> So:
>>
>> char[] a = readText!(char[])("filename");
>
> Thanks, that works!
>
> But... I'm so confused by D's fifty different string types.
>
> I can run .strip() on a char[]. But I can't run .replace('\n','?') ?
>
> So then I convert char[] to a temporary string and run replace on that.
>
> but then writefln("%s") doesn't accept strings! Only char[].
>
>   char []t = cast(char[])(c[i-15 .. i+1]).strip();
>   string s = text(t); //s.replace('\n','?')
>   writefln(" - [%s]", s); // fail
>
> main.d(89): Error: template std.array.replace cannot deduce function from argument types !()(char[], char, char), candidates are:
> /usr/include/dmd/phobos/std/array.d(2122):        std.array.replace(E, R1, R2)(E[] subject, R1 from, R2 to) if (isDynamicArray!(E[]) && isForwardRange!R1 && isForwardRange!R2 && (hasLength!R2 || isSomeString!R2))
> /usr/include/dmd/phobos/std/array.d(2255):        std.array.replace(T, Range)(T[] subject, size_t from, size_t to, Range stuff) if (isInputRange!Range && (is(ElementType!Range : T) || isSomeString!(T[]) && is(ElementType!Range : dchar)))
>
>
> What's going on here?

WAIT! This is my fault (not that I was saying it was "D's" fault, just that I was  confused).

it's not replace '' ''. It's replace "" "".  For some reason, I must have been thinking it was per-character (which is what I'm doing) so I should be using single quotes.

So I CAN run .replace("","") on a char[], just as I can a string. And THANK GOODNESS because I thought one of the major advantages of D was being relatively orthogonal/type agnostic and if I was going to have to remember "X() runs only on Y" for 3+ different string types that would be a nightmare!

On 03/09/2018 7:38 PM, Chris Katko wrote:
> On Monday, 3 September 2018 at 06:28:38 UTC, bauss wrote:
>> On Monday, 3 September 2018 at 06:25:23 UTC, bauss wrote:
>>> On Monday, 3 September 2018 at 03:19:39 UTC, Neia Neutuladh wrote:
>>>> On Monday, 3 September 2018 at 03:04:57 UTC, Chris Katko wrote:
>>>>> This should be simple? All I want to do is load an entire file, and access individual bytes. The entire thing. I don't want to have know the file size before hand, or "guess" and have a "maximum size" buffer.
>>>>>
>>>>> So far, all google searches for "dlang binary file read" end up not working for me.
>>>>>
>>>>> Thank you.
>>>>
>>>> http://dpldocs.info/experimental-docs/std.file.read.1.html
>>>>
>>>> import std.file : read;
>>>> auto bytes = read("filename");
>>>>
>>>> This gives you a void[], which you can cast to ubyte[] or char[] or whatever you need.
>>>
>>> Or he could do readText() which returns a string, which in turn will give a proper char array when casted.
>>
>> Actually ignore the casting thing, looking at readText it takes a template parameter.
>>
>> So:
>>
>> char[] a = readText!(char[])("filename");
> 
> Thanks, that works!
> 
> But... I'm so confused by D's fifty different string types.

Only three. string, wstring and dstring. They are all aliases for immutable(Char)[].

> I can run .strip() on a char[]. But I can't run .replace('\n','?') ?

Replace is working on arrays, use " not '. There is a dedicated version for characters (tr).

> So then I convert char[] to a temporary string and run replace on that.

import std.stdio;
import std.array;

void main()
{
    char[] text = "123\nhi".dup;
    text = text.replace("\n", "?");
    text.writeln;
}

> but then writefln("%s") doesn't accept strings! Only char[].
> 
>    char []t = cast(char[])(c[i-15 .. i+1]).strip();
>    string s = text(t); //s.replace('\n','?')
>    writefln(" - [%s]", s); // fail

Looks ok to me:

import std.stdio;

void main()
{
    string s = "text";
    writefln(" - [%s]", s);
}