It also allocates 1MB just to print three numbers. Yikes. On Tue, Sep 22, 2015 at 4:34 PM, Daniel Carrera <dcarr...@gmail.com> wrote:
> Hmm... I know it's horrible, but I just added that to my juliarc file :-) > > This function is 100x slower than the macro, at about 100 lines in 0.5s. I > know that's horribly slow for traditional printf() but it's fast enough for > terminal output. > > > > On 22 September 2015 at 22:06, Stefan Karpinski <ste...@karpinski.org> > wrote: > >> Possible, but I don't relish the thought of forever explaining to people >> that they need to use printf with or without the @ depending on if they >> want it to be fast or flexible. If you really don't care about speed, you >> can just do this right now: >> >> printf(fmt::AbstractString, args...) = @eval @printf($(bytestring(fmt)), >> $(args...)) >> >> >> But actually don't do that because it's so horrifically slow and >> inefficient I just can't. >> >> On Tue, Sep 22, 2015 at 3:57 PM, Daniel Carrera <dcarr...@gmail.com> >> wrote: >> >>> >>> On 22 September 2015 at 20:40, Stefan Karpinski <ste...@karpinski.org> >>> wrote: >>> >>>> I think that before any further discussion takes place of how easy or >>>> hard implementing a high-performance printf is, anyone who'd like to >>>> comment should spend some time perusing GNU libc's vfprintf >>>> implementation >>>> <http://repo.or.cz/w/glibc.git/blob/ec999b8e5ede67f42759657beb8c5fef87c8cc63:/stdio-common/vfprintf.c>. >>>> This code is neither easy nor trivial – it's batsh*t crazy. >>>> >>> >>> That is insane... 2388 lines, half of it macros, and I have no idea how >>> it works. >>> >>> >>> >>>> And we want to match its performance yet be much more flexible and >>>> generic. The current printf implementation does just that, while being >>>> somewhat less insane GNU's printf code. If someone has bright ideas for how >>>> to *also* allow runtime format specification without sacrificing >>>> performance or generality, I'm all ears. >>>> >>> >>> >>> This might be a stupid question, but what's the harm in sacrificing >>> performance as long as we keep the current @sprintf for scenarios that call >>> for performance? I don't always need printf() to be fast. >>> >>> >>> >>> >>>> I have some thoughts, but they're just that – thoughts. One option is >>>> to change the design and avoid printf-style formatting altogether. But then >>>> I'm sure I'll never hear the end of it with people kvetching about how we >>>> don't have printf. >>>> >>> >>> Probably. Everyone is used to printf and they are comfortable with it. >>> >>> Daniel. >>> >> >> >
