Undefined operator "<-" and -2 < -1

[bsxfan]

This comparison fails unexpectedly:

julia> -2<-1
ERROR: <- not defined

So it seems that <- is parsed as an as yet unused operator. One way to have your cake and eat it, is to define:

(<-)(x,y) = <(x,-y)

which will make -2<-1 work as expected, and still leave <- available as a new user-defined operator.

Are there plans to use <- for something in future?

And by the way, are there any plans to make available any other new user-defined operators?

[pao]

Parsing of <- is currently exploited by Monads.jl. I am not aware of other uses.

[diegozea]

Isn't used on base/

grep "<-" ~/bin/julia-master/base/*.jl
/home/dzea/bin/julia-master/base/bitarray.jl:# shorthand forms BitArray <-> Array

But is in src/ :

grep "<-" ~/bin/julia-master/src/*
/home/dzea/bin/julia-master/src/julia_flisp.boot:                    |\|\|| && <- -- --> > < >= <= == === != !== .> .< .>= .<=
/home/dzea/bin/julia-master/src/julia_flisp.boot:                      #7=(<- -- -->) #10=(> < >= <= == === != !== .> .< .>=
/home/dzea/bin/julia-master/src/julia-parser.scm:     (<- -- -->)

[JeffBezanson]

I wanted to leave various operators around for custom use, but my first reaction here is to remove this. An expression like x<-y is too basic to interfere with.

[pao]

I know we already lost a couple arrowlike operators (#1267); it'd be nice to have some alternative if possible.