Profile.print() throws exception if function name has Greek characters

[ArchRobison]

Functions with Greek letters in their name cause Profile.print() to throw an exception.

julia> function Δ(x)
           s = 0
           for i=0:10000
               s += sin(0.3*i)
           end
           s
       end
Δ (generic function with 1 method)

julia> @profile Δ(10)
6.645736017896336

julia> Profile.print()
ERROR: invalid ASCII sequence
 in convert at ascii.jl:97
 in lookup at profile.jl:93
 in tree at profile.jl:361
 in print at profile.jl:35
 in print at profile.jl:42 (repeats 2 times)

julia> versioninfo()
Julia Version 0.3.0-prerelease+1531
Commit 4b37277* (2014-02-11 22:49 UTC)
Platform Info:
  System: Linux (x86_64-linux-gnu)
  CPU: Intel(R) Core(TM) i5-4670T CPU @ 2.30GHz
  WORD_SIZE: 64
  BLAS: libmkl_rt
  LAPACK: libmkl_rt
  LIBM: libopenlibm

[kmsquire]

cc:@timholy

[timholy]

@carlobaldassi, your second patch looks good to me, feel free to merge.

[timholy]

Ah, saw it was a PR. Thanks!

[ArchRobison]

Thanks! I've gotten hooked on using Greek symbols where they are mathematical tradition.

[milktrader]

How do you write the delta symbol in the method?

[ArchRobison]

I've been using Vim as my editor on Linux. It has a digraph feature. For exampe, typing ctrl-K D* produces an upper case delta. What I haven't figured out yet is how to get Vim on Windows to do likewise.

[StefanKarpinski]

I kind of suspect that this is a bit of a chicken and egg problem: programmers won't start using Unicode identifiers until it's easier to enter them in editors but editors don't have any real reason to make it easier to enter Unicode until there's demand for it. Maybe by providing good support for Unicode in programs, Julia is nudging the balance towards a future where it's both easy and common to use Unicode when programming.

[milktrader]

Oh wow, that's cool. How do you call the method from repl then?

[milktrader]

Sorry for this being unrelated to the issue at hand. I can get repl to recognize the file where Δ(x) = 2x is defined with

julia> include("delta.jl")
Δ (generic function with 1 method)

But how do you call this method from repl?

julia> '\u0394'(2)
ERROR: type: apply: expected Function, got Char

[StefanKarpinski]

Yeah, that won't work, I'm afraid. I've mostly used cut-and-paste for this sort of thing. Once @loladiro's pure Julia REPL gets merged, I'd like to take a crack at fancy zsh-style identifier tab completion that would let you cycle through the options with tab and arrow keys. That way you could just tab-complete names with Unicode in them without having to retype them.

[milktrader]

Yeah, this will be a very cool add.

[milktrader]

cut and paste works btw, which is a good start

[Keno]

On Mac, you can use Ctrl+Command+Space to open up a special character viewer, which is quite convenient.

[jiahao]

Cut and paste is really the way to go. If you type it in de novo, chances are you'll run into #5434, which #5462‎ was meant to begin addressing.

[milktrader]

I really love to be able to do this

julia> Σ(x) = cumsum(x)
Σ (generic function with 1 method)

julia> Σ([10:12])
3-element Array{Int64,1}:
 10
 21
 33

[milktrader]

@jiahao thanks for the issue links

[kmsquire]

If there are any emacs users:

M-x set-input-method RET TeX

will let you type any of these: http://en.wikibooks.org/wiki/LaTeX/Mathematics#List_of_Mathematical_Symbols

(I think @JeffBezanson also mentioned this previously.)

[carlobaldassi]

On Linux: I just use a bunch of extra custom definitions in .XCompose. This way, ComposeKey+space+a → α etc. I find this extremely convenient (α becomes easier to type then alpha), bindings are easy to memorize, and can be used in any editor and in the REPL in the same way.

In case anyone wants to do the same, it's a matter of:

1. finding your system XCompose (mine: /usr/share/X11/locale/en_US.UTF-8)
2. copying it to your home directory under the name .XCompose
3. appending the extra definitions linked above at the end of it
4. setting up the "xim" module, in my case that means adding this line to ~/.gnomerc: export GTK_IM_MODULE="xim"
5. restarting X

[ArchRobison]

The problem for Vim on Windows is that the default font was missing Greek and (I'm not sure) the default file encoding might have been wrong. Here is my _gvimrc that fixed the problem.

set guifont=Lucida_Console:h10:b
set enc=utf-8
set fileencoding=utf-8