(def reduce (f xs)
      ((rfn rdc (a s)
        (if (no s)
          a
          (rdc (f a (car s)) (cdr s)))) (car xs) (cdr xs)))

As a guess, 'best' is probably used for http://arclanguage.org/best in the news.arc code. In which case it's probably not an issue... ?

I don't see the purpose of 'best. I don't see a bigger purpose in most of Arc. If what Arc gives me isn't what I need, I reinvent it.

(In fact, I think if we try to keep working on the same language, rather than tearing it down and reinventing it, we're worrying about at least some kind of "support" and stifling our development. But too much tearing down can be destructive too, of course. :-p I appreciate that you're applying a scientific-ish mindset to this.)

There are a few ways to cut through this Arc ennui:

- If Arc gives me tools I can use to reinvent things, those tools are extra-relevant, since even if I don't like them I'll use them on my way to replacing them. This is not something 'best does for me.

- Sometimes we may want everyone in the language community to use the same variant of something, so that the tools we build around that thing can work together. Are we trying to optimize 'best in the compiler/runtime? Nope. Do people often extend 'best with extra capabilities? Nope. Even if these things were true, are we even having an issue with people reinventing 'best all the time? Nope, I don't think so.

For example, in Clojure, I can just build my project by excluding the function in question and replace it with my version. Anyone else that wants to use Clojure doesn't need to worry about another persons great idea.

; example

  (ns a-project.core
    (:refer-clojure :exclude (best))
    (:gen-class))
  
  (defn best []
    ...)

  (ns your-project.core
    (:refer-clojure :exclude (best))
    (:use [a-project :only (best)])
    (:gen-class))
   
   (defn do-my-stuff []
    (best ....))

  (def reduce (func xs)
    (whenlet (x . xs) xs
      (foldl func x xs)))

Alternatively we could have this...

  (def reduce (func xs)
    (iflet (x . xs) xs
      (foldl func x xs)
      (func)))

The original classTextile.php (http://code.google.com/p/textpattern/source/browse/developme... -- warning: big) provides a 'restricted' mode, designed for forum comments etc., in which all input <, > and & characters are escaped, which is what I intend to do here as I continue to work on it.

> It strikes me that this wouldn't handle nesting well, which may be fine, 'cause these spans are things people almost never need to nest--some exceptions being when attributes are involved or when nesting multiple layers of <sup> and <sub>. To make it a bit less sloppy, I recommend manually incrementing an index through the text, using 'begins to identify start tags and maintaining a stack if necessary, even if it sounds horribly ugly to do it that way. :-p This should also give you a good place to insert attribute-parsing code.

While you're right about the attribute-parsing, I'm not too concerned about nesting issues because the current reference implementation (there's a dingus at http://textile.sitemonks.com/) doesn't handle that either. It uses the regexp method too (see classTextile.php), with a callback for parsing attributes.

> Speaking of spans, I'm not sure why you bother making all the txt-@ global variables. I think all you do is use 'eval to define them and another 'eval to get them back, and you don't even need the second 'eval because you have all the information you need.

Thanks. I've now corrected my copy and I'll use your method in the next version.

> Also speaking of spans, I'm troubled by the fact that there's a -del- span at all. I hope this syntax doesn't apply to every instance of a hyphen before a whitespace character, 'cause that'll mess up a lot of variable names and links.

> Speaking of which, lots of links have +pluses+ in them as URL-encoded spaces, so that's a troublesome syntax too. What does Textile do in these cases?

Good point, that's a special case I missed. The function is now:

    (def txt-span (text st et tag) ; st = start textile; et = end textile -- todo: support span attributes
      (re-replace (string "(?<=\\W|^)" (txt-re-quote st) "(\\S.*?\\S?)" (txt-re-quote et) "(?=\\W|$)") text (string "<" tag ">" #\\ 1 "</" tag ">")))

> I realize you're in the earlier stages of getting to know Arc, and I don't mean to discourage you or anything. I only mean to contribute. ^_^

Yes! Thank you for your contribution -- it's for advice like this that I released so early.

> The suggestion that comes to my mind is this, but it's kinda laughable....

Yeah, I'll stick with my `str-split` for now. It should be a library function anyhow, so I'd rather keep my version short and simple until there's a version in `strings.arc` or `arc.arc`.

> Apparently you can just keep using 're-replace but pass a function as the "replacement" argument. It appears to work very much like preg_replace_callback(), except that each captured string is passed as a separate argument rather than in an array

Aha, I don't know why I didn't think to try that. I just mentally assumed I would need another function to do it.

Thanks for all your help! I really appreciate it.

1. Alice is writing a blog entry declaring her unrequited love for Bob.

2. Alice includes a quote from Bob's blog by copying-and-pasting. Bob is using UTF-8 charset, and the copied section includes some Unicode curled quotes, because Bob is typographically sensitive.

3. Because Alice is using a backwards text editor which refuses to believe there is something other than 1 byte = 1 character and plain ASCII in the lower half, it shows the characters exactly as Alice and Bob intended (such a third-rate text editor is sure to be using the operating system's standard text editing control, which will know about such tricks) -- but internally it has crapped up the representation, and lo:

4. When Alice submits this onto her ISO-8859-1-encoded blog, she will have mixed character sets and invalid XML and all of a sudden her well-written love letter is smeared by �s where there ought to be “s and ”s.

Further reading:

- http://textism.com/article/663/pomegranate

- http://daringfireball.net/2003/02/short_and_curlies