From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2003-03-22T03:24:09+09:00
Subject: Re: Proposal: new operator: '<-' (for assignments)

In article <024d01c2efbc$2fa7a040$6401a8c0@MELONBALLER>,
Chris Pine <nemo@hellotree.com> wrote:
>----- Original Message -----
>foo = Foo.new("this value")
>...later...
>foo <- "some new value"
>----------------------------
>
>This looks backwards to me.  What I mean is, shouldn't the arrow point the
>other way?  It seems closer to how hashes literals work, for example.  The
>"variable" points to the "value".

Hmmm... I guess I read it as 'foo takes the value "some new value"

>
>In any case, I don't think you can have left arrows like <- and <=:  <= is
>taken (and isn't an arrow :) and <- might be used in code like 'a<-b' (is
>`a' less than negative `b'?).

Aye, there's the rub...

>
>So how would you feel about -> ?
>
>Honestly, I'd be a little surprised if this got in to the language.
>Depending on your situation (you're trying to make a special-purpose
>language, right?) it might be better to write your own interpreter on top of
>Ruby, snarfing generously.
>
>For example, if you have a string of code like:
>
>  foo << { doSomethingHere }
>
>you could just split the string on the first '<<' and eval the substrings.
>Depending on how robust you need your language to be (I'm assuming not very,
>since you were writing it for people who aren't really programmers, IIRC),
>this should be a relatively easy task, and perfect for Ruby.  There's no
>reason the code used has to be readable by the actual Ruby interpreter, if
>you can write a couple-hundred line interpreter as a go-between.
>

I'm specifically trying to avoid writing a parser.  I want RHDL to be pure 
Ruby.

I think what I'll end up doing is using '<<' and then alias the original 
'<<' to 'shiftl'.


Phil