On Friday, 9 September 2022 at 14:22:51 UTC, Steven Schveighoffer wrote:

do {
   ...
} while(false);

Not the same, continue applies to the do then, not an outer loop. Also not clear until the end of the construct that it's not a loop.

It's easier to reason about switch because you don't have to read the whole function looking for the matching label.

    if (FuncDeclaration func = sc.parent.isFuncDeclaration())
    {
        tm.symtab = func.localsymtab;
        if (!tm.symtab)
        {
            // Inside template constraint, symtab is not set yet.
            goto L1;
        }
    }
    else
    {
        tm.symtab = sc.parent.isScopeDsymbol().symtab;
    }
    assert(tm.symtab);
    tm.ident = Identifier.generateId(s, tm.symtab.length + 1);
    tm.symtab.insert(tm);
L1:

That's an improvement.

On Friday, 9 September 2022 at 14:18:04 UTC, Paul Backus wrote:

do
{
    // ...
    if (whatever) break;
    // ...
}

So continue would do the same as break? Bit weird.
Also you don't know if it's a loop or not until you find the closing brace. It's better to know in advance.

On 9/9/22 11:40 AM, Nick Treleaven wrote:

do {
   ...
} while(false);

If we are talking about wrapping existing code that might contain a continue, you need to also consider that the existing code might contain a break. In both cases, you could label the target and use a targeted continue or break statement.

But again, goto is better here.

You don't though. Just search for it. Just like you would have to search for the matching closing brace of the switch. At least in the case of the label, you can use text search, and not have to account for nested braces.

-Steve

On Friday, 9 September 2022 at 15:57:45 UTC, Steven Schveighoffer wrote:

do {
   ...
} while(false);

If you know there's no break but there is a continue, you don't have to use a label.

Why would you need to stop reading the code sequentially and lookup the closing brace? With goto you need to to understand what you're looking at. That's my point.

On 9/9/22 12:31 PM, Nick Treleaven wrote:

So when you say "Not the same", you mean that <1% difference.

If the closing brace is close at hand, then the appropriate label would be too. It will even stand out more.

But you are saying "read the whole function". I'm assuming you mean that it's far away from the break/goto statement.

If it's off-screen, the label wins hands-down. Using my editor I can find "L1:" much easier than I can find a specific "}"

-Steve

On Friday, 9 September 2022 at 17:04:44 UTC, Steven Schveighoffer wrote:

That's where bugs hide.

Why do I need to stop reading the code sequentially and find the closing brace of a switch? I do not. Searching for a label is disruptive, even if automated, it breaks my train of thought. With goto the matching label could be inside the switch or it could be outside it, at different levels of scope. With break, you know it just jumps to the end of the switch. When I'm reading code, I'm trying to understand each statement. I can't understand a goto without knowing which scope it goes to. With break you know what scope that is. This is a key part of why we have structured programming, because you know where the code will go to when exiting a construct.