Ok,  I wish to create a standard timing system so that I can measure ~how long each function takes to execute.

I wish to be able to place at the start of a function
version(Time) mixin TimeExecution("funcName");

mixin template TimeExecution(T) if(isSomeString!T) {
    import std.stdio, std.datetime, std.conv;

    auto sw = StopWatch(AutoStart.yes);
    //	Error: Declaration expected, not '('
    scope(exit) writeln(T, ": ", to!Duration(sw.peek));
}


Why do I receive the Error when the scope statement is included?
Is this an error, or what is the rationale behind the decision?

Thank you.

On 01/13/2013 11:35 PM, 1100110 wrote:
> Ok, I wish to create a standard timing system so that I can measure ~how
> long each function takes to execute.
>
> I wish to be able to place at the start of a function
> version(Time) mixin TimeExecution("funcName");
>
> mixin template TimeExecution(T) if(isSomeString!T) {
> import std.stdio, std.datetime, std.conv;
>
> auto sw = StopWatch(AutoStart.yes);
> // Error: Declaration expected, not '('
> scope(exit) writeln(T, ": ", to!Duration(sw.peek));
> }
>
>
> Why do I receive the Error when the scope statement is included?
> Is this an error, or what is the rationale behind the decision?
>
> Thank you.

It appears that you cannot mixin *any* statement with scope([exit,success,etc]) in it.

I have been rereading my copy of TDPL, and it states that mixin statements must be valid D code, and there can be multiple 'scope()' statements.

Since "scope(exit) writeln();" is valid D code, and refuses to compile in a mixin, I assume that this is a bug.

I've been digging through the bug tracker and I cannot find a duplicate bug, so if someone can confirm that this is a bug, I'll create a report.

On 01/14/2013 07:26 AM, 1100110 wrote:
> On 01/13/2013 11:35 PM, 1100110 wrote:
>> Ok, I wish to create a standard timing system so that I can measure ~how
>> long each function takes to execute.
>>
>> I wish to be able to place at the start of a function
>> version(Time) mixin TimeExecution("funcName");
>>
>> mixin template TimeExecution(T) if(isSomeString!T) {
>> import std.stdio, std.datetime, std.conv;
>>
>> auto sw = StopWatch(AutoStart.yes);
>> // Error: Declaration expected, not '('
>> scope(exit) writeln(T, ": ", to!Duration(sw.peek));
>> }
>>
>>
>> Why do I receive the Error when the scope statement is included?
>> Is this an error, or what is the rationale behind the decision?
>>
>> Thank you.
>
> It appears that you cannot mixin *any* statement with
> scope([exit,success,etc]) in it.
>
> I have been rereading my copy of TDPL, and it states that mixin
> statements must be valid D code, and there can be multiple 'scope()'
> statements.
>
> Since "scope(exit) writeln();" is valid D code, and refuses to compile
> in a mixin, I assume that this is a bug.
>
> I've been digging through the bug tracker and I cannot find a duplicate
> bug, so if someone can confirm that this is a bug, I'll create a report.

It is not a bug. Use a string mixin.

On 01/14/2013 02:03 AM, Timon Gehr wrote:
> On 01/14/2013 07:26 AM, 1100110 wrote:
>> On 01/13/2013 11:35 PM, 1100110 wrote:
>>> Ok, I wish to create a standard timing system so that I can measure ~how
>>> long each function takes to execute.
>>>
>>> I wish to be able to place at the start of a function
>>> version(Time) mixin TimeExecution("funcName");
>>>
>>> mixin template TimeExecution(T) if(isSomeString!T) {
>>> import std.stdio, std.datetime, std.conv;
>>>
>>> auto sw = StopWatch(AutoStart.yes);
>>> // Error: Declaration expected, not '('
>>> scope(exit) writeln(T, ": ", to!Duration(sw.peek));
>>> }
>>>
>>>
>>> Why do I receive the Error when the scope statement is included?
>>> Is this an error, or what is the rationale behind the decision?
>>>
>>> Thank you.
>>
>> It appears that you cannot mixin *any* statement with
>> scope([exit,success,etc]) in it.
>>
>> I have been rereading my copy of TDPL, and it states that mixin
>> statements must be valid D code, and there can be multiple 'scope()'
>> statements.
>>
>> Since "scope(exit) writeln();" is valid D code, and refuses to compile
>> in a mixin, I assume that this is a bug.
>>
>> I've been digging through the bug tracker and I cannot find a duplicate
>> bug, so if someone can confirm that this is a bug, I'll create a report.
>
> It is not a bug. Use a string mixin.

Well, dangit.  Thanks!

>>
>> It appears that you cannot mixin *any* statement with
>> scope([exit,success,etc]) in it.
>>
>> I have been rereading my copy of TDPL, and it states that mixin
>> statements must be valid D code, and there can be multiple 'scope()'
>> statements.
>>
>> Since "scope(exit) writeln();" is valid D code, and refuses to compile
>> in a mixin, I assume that this is a bug.
>>
>> I've been digging through the bug tracker and I cannot find a duplicate
>> bug, so if someone can confirm that this is a bug, I'll create a report.
>
> It is not a bug. Use a string mixin.

What is the rationale behind this limitation?

On 01/14/2013 04:44 AM, mist wrote:
>>>
>>> It appears that you cannot mixin *any* statement with
>>> scope([exit,success,etc]) in it.
>>>
>>> I have been rereading my copy of TDPL, and it states that mixin
>>> statements must be valid D code, and there can be multiple 'scope()'
>>> statements.
>>>
>>> Since "scope(exit) writeln();" is valid D code, and refuses to compile
>>> in a mixin, I assume that this is a bug.
>>>
>>> I've been digging through the bug tracker and I cannot find a duplicate
>>> bug, so if someone can confirm that this is a bug, I'll create a report.
>>
>> It is not a bug. Use a string mixin.
>
> What is the rationale behind this limitation?

I too would like to know the reason behind the limitation...

My Code was nice and pretty incorrect.

On 2013-01-14 11:44, mist wrote:

> What is the rationale behind this limitation?

I'm not sure but it might have something to do with template mixins introduce a new scope or similar.

-- 
/Jacob Carlborg

On Monday, 14 January 2013 at 06:26:33 UTC, 1100110 wrote:
> On 01/13/2013 11:35 PM, 1100110 wrote:
>> Ok, I wish to create a standard timing system so that I can measure ~how
>> long each function takes to execute.
>>
>> I wish to be able to place at the start of a function
>> version(Time) mixin TimeExecution("funcName");
>>
>> mixin template TimeExecution(T) if(isSomeString!T) {
>> import std.stdio, std.datetime, std.conv;
>>
>> auto sw = StopWatch(AutoStart.yes);
>> // Error: Declaration expected, not '('
>> scope(exit) writeln(T, ": ", to!Duration(sw.peek));
>> }
>>
>>
>> Why do I receive the Error when the scope statement is included?
>> Is this an error, or what is the rationale behind the decision?
>>
>> Thank you.
>
> It appears that you cannot mixin *any* statement with scope([exit,success,etc]) in it.

Mixin templates are supposed to introduce *declarations* not statements.

Eg. even this shouldn't compile, should it?
---
mixin template TimeExecution(T) if(isSomeString!T) {
    import std.stdio;
    writeln(T); // statement
}
---

I thought template itself should compile but its statement-like instantiation should not.

By the way, if all you want is to split out some generic statement block without using dirty string mixins, template functions with alias parameters may do.
I.e. http://dpaste.1azy.net/68ad8133

Don't know what about inlining for it though.

> Mixin templates are supposed to introduce *declarations* not statements.
>
> Eg. even this shouldn't compile, should it?
> ---
> mixin template TimeExecution(T) if(isSomeString!T) {
>     import std.stdio;
>     writeln(T); // statement
> }
> ---

On Tuesday, 15 January 2013 at 11:19:50 UTC, mist wrote:
> I thought template itself should compile but its statement-like instantiation should not.

The template shouldn't compile: the D grammar says that mixin templates inject declarations only. Hence the text of the error.

> By the way, if all you want is to split out some generic statement block without using dirty string mixins, template functions with alias parameters may do.
> I.e. http://dpaste.1azy.net/68ad8133

Yes, but only a string mixin can inject a scope statement.