On Sunday, 6 February 2022 at 09:40:48 UTC, rempas wrote:

One reason to use read/write based I/O by default is that it's more versatile. It's kind of like an input range versus a random access in Phobos.

// Could not map file /dev/stdin (Invalid argument)
auto f = new MmFile("/dev/stdin");

On Sunday, 6 February 2022 at 09:40:48 UTC, rempas wrote:

std.file.readText() is just fine... your really want to do an os with call fgetc for every single byte that has to be read ?

On Tuesday, 8 February 2022 at 03:33:11 UTC, Steven Schveighoffer wrote:

Thanks for your time Steve! I will do proper testing like you suggested and see! It will take some time but I think it's worth it rather than randomly choose between one of them :)

On Tuesday, 8 February 2022 at 21:37:29 UTC, sarn wrote:

// Could not map file /dev/stdin (Invalid argument)
auto f = new MmFile("/dev/stdin");

Yeah, thank you! I will open and read the whole file anyways so it seems that it makes sense to try with this method and then measurement my program in the future to see! Have a nice day!

On Wednesday, 9 February 2022 at 02:07:05 UTC, user1234 wrote:

Good point! I was really wondering if "fgetc" does a system call every single time that it is called or if the text is buffered just like with "printf". I will use "read" in any case just to be sure tho. I don't want to use Phobos tho so I cannot use "file.readText". Thank you for your time!

On Saturday, 12 February 2022 at 13:17:19 UTC, rempas wrote:

I think that nowadays fgetc does not make sense anymore, maybe in the past when the amount of memory available was very reduced... source files are 100 kb top. You can load 100 of them, the fingerprint is still small. What will likely consume the more is the AST.

Otherwise readText is easy to translate, it's just fopen then fread then fclose, + a few checks for the errors, not a big deal to translate.

On Saturday, 12 February 2022 at 16:48:26 UTC, user1234 wrote:

The problem with phobos and if used to program a compiler is dynamic arrays, because of how they are managed.

With Styx I had used phobos because I knew the memory management was designed to work similarly with arrays, i.e functions can return arrays, but using the "sink" style would have not caused any problem (by "sink" style I mean when the buffer is owned by the calling frame, and passed as parameter, e.g like in many C-style APIs)

Then the amount of phobos code to translate in order to bootstrap was minimal:

std.paths:

• isAbsolute
• isDir
• isFile
• dirName
• baseName
• exists
• cwd
• dirEntries
• setExtension

std.files:

• read (or readText)
• write (not even used I realize now)

std.process

• pipeProcess (actually just used to optionally --run after compile)

std.getopt

• getopt (tho libc functions for that could have been used... dmd itself doesnt have any special functions for the arg processing in the driver IIRC)

Add to this a few things from libc and unistd and you're good. You dont need more.

On 2/8/22 9:07 PM, user1234 wrote:

Just a clarification here -- fgetc does NOT do an OS system call for every character. It's a C library function, which uses a FILE *. And this is not a new development -- my ANSI C book from 1988 talks about how FILE has a buffer.

While it does not do a system call (unless the buffer is empty and it needs to fill the buffer), it's still an opaque call, which might cost a decent amount if you are reading by character.

-Steve