Arc Forumnew | comments | leaders | submitlogin
2 points by evanrmurphy 3747 days ago | link | parent

The escaping system is more robust than I realized. I think some of my concerns are definitely addressed with being able to assign escaped numerical characters, etc.

> However, I could see this being done: have nil be escapable, so that |nil| is the symbol you can rebind, while nil is the literal empty list. ...And then are they eq?

I looked into this and think it's kind of elegant now. 'nil is unescapable like non-special character symbols in general are [1]:

  arc> (is 'nil '\n\i\l '|nil|)    ; like your 'ach example
But () is escapable (as special characters typically are):

  arc> (= |()| "escaped empty set")
  "escaped empty set"
Like typical escaped characters, it isn't eq to nil and () unless you assign it that way:

  arc> (is () |()|)
  arc> (= |()| nil)
  arc> (is nil () |()| \(\))
[1] I was frustrated momentarily when I couldn't escape 't until I realized it was the same way. As you pointed out, at least it is locally rebindable by default. And then I suppose 't isn't an especially desirable global variable name anyway.