optimatization suggestion

[Stefan Koch via Digitalmars-d]

On Saturday, 1 April 2017 at 17:15:54 UTC, Inquie wrote:
> I use a lot of code that has string appending and it seems like 
> it could be optimized;
>
> wchar[] x;
>
> x ~= "This is one line";
> x ~= "This is another line";
>
> could become
>
> x ~= "This is one lineThis is another line";
>
> The rewrite rule is very simple:
>
> if char type array is being appended to with literal string and 
> next line also has appender with literal string, then combine 
> in to one appender.
>
> More complex cases could be handled such as
>
> x ~= "This is one"~x~" line";
> x ~= "This is another line";
>
> which turns in to
>
> x ~= "This is one"~x~" lineThis is another line";
>
> Since these are done in ctfe, it may improve the speed 
> significantly in some cases!? (usually the splitting up is for 
> readability and to allow for easy modification)

Cannot be done reliably without proper data-flow analysis.