digitalmars.D.learn - Avoid compile time evaluation
- Andrea Fontana (24/24) Apr 13 2012 If I have something like:
- Simen Kjaeraas (10/29) Apr 13 2012 Indeed.
- Andrea Fontana (3/43) Apr 13 2012 That's strange, so why writeln make it compile faster? :)
If I have something like: static int var = myFunction(); dmd will evaluate myFunction() at compile time. If it can't, it gives me a compile error, doesn't it? If I'm not wrong, static force this. If i don't use static, dmd will try to evaluate myfunction() at compile time, and if it can't, myfunction() will be executed at runtime, right? So I have a code like this: ... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... ... static int var = myVeryVeryComplexFunction(); If i have to work to some code before my complex function, every time I have to re-compile code, it takes a lot because dmd evalute at compile time myVeryVeryComplexFunction() also if i don't use static. Does a keyword to force runtime evaluation exists? I can't find any documentation (neither on static used in this way, any link?)... My dirty way to do this is to edit myVeryVeryComplexFunction() adding a writeln() (or something similar) to function body.
Apr 13 2012
On Fri, 13 Apr 2012 14:52:05 +0200, Andrea Fontana <nospam example.com> wrote:If I have something like: static int var = myFunction(); dmd will evaluate myFunction() at compile time. If it can't, it gives me a compile error, doesn't it? If I'm not wrong, static force this.Indeed.If i don't use static, dmd will try to evaluate myfunction() at compile time, and if it can't, myfunction() will be executed at runtime, right?No. static or enum forces evaluation at compiletime, otherwise it's runtime. Conceivably, the compiler could try running every function at compile-time as an optimization, but that would completely destroy the nice compilation times we like to brag about, and likely also break a lot of code.So I have a code like this: ... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... ... static int var = myVeryVeryComplexFunction(); If i have to work to some code before my complex function, every time I have to re-compile code, it takes a lot because dmd evalute at compile time myVeryVeryComplexFunction() also if i don't use static. Does a keyword to force runtime evaluation exists? I can't find any documentation (neither on static used in this way, any link?)...See above. Runtime evaluation is the default, and compile-time needs to be forced.
Apr 13 2012
"Andrea Fontana" <nospam example.com> That's strange, so why writeln make it compile faster? :) I can't post the code, i'll try to reproduce it... On Friday, 13 April 2012 at 13:01:03 UTC, Simen Kjaeraas wrote:On Fri, 13 Apr 2012 14:52:05 +0200, Andrea Fontana <nospam example.com> wrote:If I have something like: static int var = myFunction(); dmd will evaluate myFunction() at compile time. If it can't, it gives me a compile error, doesn't it? If I'm not wrong, static force this.Indeed.If i don't use static, dmd will try to evaluate myfunction() at compile time, and if it can't, myfunction() will be executed at runtime, right?No. static or enum forces evaluation at compiletime, otherwise it's runtime. Conceivably, the compiler could try running every function at compile-time as an optimization, but that would completely destroy the nice compilation times we like to brag about, and likely also break a lot of code.So I have a code like this: ... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... // Here some code to debug/fix... ... static int var = myVeryVeryComplexFunction(); If i have to work to some code before my complex function, every time I have to re-compile code, it takes a lot because dmd evalute at compile time myVeryVeryComplexFunction() also if i don't use static. Does a keyword to force runtime evaluation exists? I can't find any documentation (neither on static used in this way, any link?)...See above. Runtime evaluation is the default, and compile-time needs to be forced.
Apr 13 2012