How about submitting a patch to Formatting.jl? On Sunday, September 27, 2015, Michael Hatherly <michaelhathe...@gmail.com> wrote:
> As mentioned in the other thread, > https://groups.google.com/d/msg/julia-users/hBbEGEopi0A/OX4ZEhFnBgAJ and > https://groups.google.com/d/msg/julia-users/hBbEGEopi0A/fKQcqDEVBgAJ, > there are concerns about generating new code for every single formatting > string used. I guess generally this won’t be much of an issue, but it could > be. Maybe write a package and see how much interest there is first? > > — Mike > > On Sunday, 27 September 2015 13:02:25 UTC+2, Daniel Carrera wrote: >> >> Hello, >> >> I made a trivial change to a some clever code by Tim Holy, and used it to >> make printf() and sprintf() function with the familiar syntax that we know >> from C/C++ (requires Julia 0.4): >> >> >> immutable FormatString{S} end >> >> FormatString(str::AbstractString) = FormatString{symbol(str)} >> >> @generated function Base.print{format}(::Type{FormatString{format}}, >> args...) >> meta = Expr(:meta, :inline) >> fmt = string(format) >> allargs = [:(args[$d]) for d = 1:length(args)] >> quote >> @printf($fmt, $(allargs...)) >> end >> end >> @generated function Base.sprint{format}(::Type{FormatString{format}}, >> args...) >> meta = Expr(:meta, :inline) >> fmt = string(format) >> allargs = [:(args[$d]) for d = 1:length(args)] >> quote >> @sprintf($fmt, $(allargs...)) >> end >> end >> >> function printf(s::AbstractString, args...) >> print(FormatString(s), args...) >> end >> function sprintf(s::AbstractString, args...) >> print(FormatString(s), args...) >> end >> >> >> Could (or should) something like this be included in Julia by default? >> The first time you call printf() sprintf() with a new format string, the >> function call is slower than the @printf and @sprintf macros, but >> subsequent calls are just as fast: >> >> julia> @time @printf("%7d %7.2f", 220/7, 22/7) >> 31 3.14 0.024334 seconds (20.68 k allocations: 912.738 KB) >> >> julia> @time @printf("%7d %7.2f", 220/7, 22/7) >> 31 3.14 0.000102 seconds (30 allocations: 1.094 KB) >> >> julia> >> >> julia> fmt = "%6d %7.2f" >> "%6d %7.2f" >> >> julia> @time printf(fmt, 220/7, 22/7) >> 31 3.14 0.036154 seconds (36.81 k allocations: 1.675 MB) >> >> julia> @time printf(fmt, 220/7, 22/7) >> 31 3.14 0.000095 seconds (37 allocations: 1.250 KB) >> >> >> >> Daniel. >> >
