Load entire file, as a char array.

[Chris Katko]

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!