On Mon, Feb 23, 2009 at 10:42 AM, Mark Volkmann <r.mark.volkm...@gmail.com> wrote: > > I have an idea I'd like to float to see if there are reasons why it's > a bad idea. > > What if Clojure had an alternate "surface" syntax that was translated > into standard Clojure syntax by a kind of preprocessor? > > Many people that don't like Lisp dialects don't like them because of > the parentheses. I'm trying to address that. > > Here's a simple example of valid Clojure code. > > (defn pig-latin [word] > (let [first-letter (first word)] > (if (.contains "aeiou" (str first-letter)) > (str word "ay") > (str (subs word 1) first-letter "ay")))) > > (println (pig-latin "red")) > (println (pig-latin "orange")) > > Here's what that same code would look like in my alternate syntax. > > defn pig-latin [word] > let [first-letter (first word)] > if .contains "aeiou" (str first-letter) > str word "ay" > str (subs word 1) first-letter "ay" > > println (pig-latin "red") > println (pig-latin "orange") > > The rules for turning this into standard Clojure syntax are pretty simple. > > 1) If a line is indented farther than the previous one, it is part of > the previous line. > 2) If a line doesn't start with a (, then add one. > 3) If the next line is indented less than this one, add the > appropriate number of )'s at the end. > 4) If the first token on a line is "if" and the first non-whitespace > character after it is not ( > then assume the rest of the line is the condition and wrap it in ( ). >
If the procedure application uses a nested expression to select the procedure to apply, it looks like using your heuristics, the parentheses cannot be omitted: Clojure: ((if (< x 0) - +) x) Haskell: (s-expression with optional parentheses and infix operators): (if (x < 0) then (\x -> -x) else id) x Using your proposed rules, this does not work (if (< x 0) - +) x as the line starts with parentheses, and so the parser will assume parentheses do not need to be added A Haskell-like parser would be kind of cool, though -- is it worth the hassle? -- miʃel salim • http://hircus.jaiku.com/ IUCS • msa...@cs.indiana.edu Fedora • sali...@fedoraproject.org MacPorts • hir...@macports.org --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
