Julia REPL paste "magic" macro


#1

I use Python and Julia and use the REPL a lot in both.

One thing I really like in the Python ecosystem is IPython (yes, I’m aware of IJulia :slight_smile: ).
One particular feature I use a lot of in IPython is the %paste magic command, which takes the contents of your copy-buffer and submits them to the REPL, without showing the pasted text or entering it in your history.

I wanted something similar in the plain Julia REPL and came up with this macro:

# ~/.juliarc.jl
module __magic__

    export @paste

    """Evaluate the copy buffer"""
    macro paste()
        include_string(clipboard());
    end

end

importall __magic__

Then, in the REPL I can simply do:

julia> @paste

and whatever text I have copied will be evaluated in the Julia REPL.

Hopefully this is useful to someone!


#2

Is this different from just typing Ctrl-V (or command-V on Mac)?


#3

I think the idea is that this doesn’t display the pasted text, which would be useful if one were pasting a large block of text and doesn’t want it cluttering up the screen.


#4

And specially the history.


#5

Why should this be a macro and not a function? (A lot of things IPython accomplishes with “magic” macros, i.e. extensions to Python syntax, can be accomplished with regular Julia functions.)


#6

Exactly :slight_smile:

A lot of the time I build up something larger in a text editor and since I’m iterating towards something that actually works, I don’t need any of the intermediate steps on screen or in history.


#7

True - it could definitely be a function - I was looking for something that looked similar to what I was familiar with in IPython (%paste -> @paste) - I also didn’t want to have to type the empty brackets (e.g. paste()) so a macro worked well for that.

An earlier version I’d played around with was this:

# ~/.juliarc.jl
module __magic__

    export paste

    """Evaluate the copy buffer"""
    function _paste()
        include_string(clipboard());
    end

    """Wrapper to call function when displayed at the REPL"""
    type DisplayWrapper{F <: Function}
        f::F
    end
    (x::DisplayWrapper)(args...; kwargs...) = x.f(args...; kwargs...)
    Base.display(x::DisplayWrapper) = x.f()

    paste = DisplayWrapper(_paste)

end

importall __magic__

which abused the display method at the REPL to allow you to paste by simply executing:

julia> paste