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May 18, 2015 control flow with a functional template ? | ||||
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who's never had to do this: --- if (comparison) { statement; break; } --- ans then thought it's a pity to open/closes the braces just for a simple statement. Would it be possible to have a template to simplify this to: --- if (comparison) Break!(expression); --- or even at the language level: --- if (comparison) break(expression); if (comparison) continue(expression); --- so far it looks like it's only possible using a string mixin, which is a quite unelegant solution (because for example you loose the IDE completion while writting the statement): --- auto Break(string statement) { return format("{%s;break;}", statement); } // unelegant but works... if (condition) mixin("myVar = 8".Break); if (condition) mixin(q{myVar = 8}.Break); --- Any other solution ? |
May 18, 2015 Re: control flow with a functional template ? | ||||
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Posted in reply to Baz | On Monday, 18 May 2015 at 06:13:50 UTC, Baz wrote:
> who's never had to do this:
>
> ---
> if (comparison)
> {
> statement;
> break;
> }
> ---
>
> ans then thought it's a pity to open/closes the braces just for a
> simple statement. Would it be possible to have a template to
> simplify this to:
>
> ---
> if (comparison)
> Break!(expression);
> ---
>
> or even at the language level:
>
> ---
> if (comparison)
> break(expression);
> if (comparison)
> continue(expression);
> ---
>
> so far it looks like it's only possible using a string mixin,
> which is a quite unelegant solution (because for example you loose the IDE completion while writting the statement):
>
> ---
> auto Break(string statement)
> {
> return format("{%s;break;}", statement);
> }
> // unelegant but works...
> if (condition)
> mixin("myVar = 8".Break);
>
> if (condition)
> mixin(q{myVar = 8}.Break);
> ---
>
> Any other solution ?
Take a look at lazy function arguments if you really want this. Personally I think you'll end up saving a small handful of keystrokes (if any) at the expense of clarity.
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May 18, 2015 Re: control flow with a functional template ? | ||||
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Posted in reply to John Colvin | On Monday, 18 May 2015 at 08:46:36 UTC, John Colvin wrote:
> On Monday, 18 May 2015 at 06:13:50 UTC, Baz wrote:
>> who's never had to do this:
>>
>> ---
>> if (comparison)
>> {
>> statement;
>> break;
>> }
>> ---
>>
>> ans then thought it's a pity to open/closes the braces just for a
>> simple statement. Would it be possible to have a template to
>> simplify this to:
>>
>> ---
>> if (comparison)
>> Break!(expression);
>> ---
>>
>> or even at the language level:
>>
>> ---
>> if (comparison)
>> break(expression);
>> if (comparison)
>> continue(expression);
>> ---
>>
>> so far it looks like it's only possible using a string mixin,
>> which is a quite unelegant solution (because for example you loose the IDE completion while writting the statement):
>>
>> ---
>> auto Break(string statement)
>> {
>> return format("{%s;break;}", statement);
>> }
>> // unelegant but works...
>> if (condition)
>> mixin("myVar = 8".Break);
>>
>> if (condition)
>> mixin(q{myVar = 8}.Break);
>> ---
>>
>> Any other solution ?
>
> Take a look at lazy function arguments if you really want this. Personally I think you'll end up saving a small handful of keystrokes (if any) at the expense of clarity.
Wait no, actually you do need mixins, I wasn't thinking. Unless you make the if statement a function call / template...
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