Re: _Symbols _with _leading _underscores

[j via Digitalmars-d-learn]

On Saturday, 17 December 2022 at 02:42:22 UTC, Paul wrote:

I see code like this from time to time. Are the leading underscores significant, in general, in the D language? Is it just programmer preference? Is it a coding practice, in general, that is common...even outside of D? Thanks for any assistance.

From: http://dpldocs.info/this-week-in-d/Blog.Posted_2022_10_10.html#hello-arduino

```d
import ldc.llvmasm;

// Ports from the delay_basic.h in the thing
void _delay_loop_1(ubyte __count) {
        // this template param is required to avoid

// assertion `!Call.getType()->isVoidTy() && "Bad inline asm!"' failed.

        __asm!ubyte (
                "1: dec $0\n\tbrne 1b",
                "=r,0", (__count)
        );
}
void _delay_loop_2(ushort __count) {
        __asm!ushort (`
        1: sbiw $0,1
        brne 1b
        `,
        `=w,0`,
        __count);
}

// port from delay.h in arduino thing
enum F_CPU = 1_000_000UL;

// this was _delay_ms but i did something wrong and changed double to int and i still don't love it

void _delay(int __ms) {
        ushort __ticks;
        ulong __tmp = (F_CPU * __ms) / 4000;
        if(__tmp < 1)
                __ticks = 1;
        else if(__tmp > 65_535) {
                __ticks = cast(ushort) (__ms * 10.0);
                while(__ticks) {
                        _delay_loop_2(cast(ushort) (((F_CPU) / 4e3) / 10));
                        __ticks--;
                }
                return;
        } else
                __ticks = cast(ushort) __tmp;
        _delay_loop_2(__ticks);
}
```

C and C++.