I'll add that: (cond (foo bar) (baz plugh)) => (cond (foo) (bar) (baz) (plugh))
This particular CL difference is listed on the wiki page you listed: http://en.wikibooks.org/wiki/Clojure_Programming#Clojure_for_Common_Lisp_Programmers I also didn't have anywhere near these kinds of problems getting things to work, although I've been doing a lot of Java lately, and more Scheme than CL, so that may have helped. I'm sure other folks would also be interested in your contributions towards a CL => Clojure document; sounds like a good opportunity. Dave --- On Sun, 11/16/08, Brian W <[EMAIL PROTECTED]> wrote: > I'm going to assume this is serious and not a joke, but you do > realize Clojure is already quite well documented at clojure.org? > > #t t => true > define defun => defn > car, cdr, caar, etc. ~> first, rest, ffirst, rrest, > frest, rfirst > > arglists are vectors because [ ] stand out better > > On Nov 16, 2:31 pm, Simon Brooke > <[EMAIL PROTECTED]> wrote: > > Has anyone written a very simple introduction to > Clojure for LISP > > hackers? I've spend an evening playing with it > pretty intensively, and > > thus far I haven't got a thing to work. I've > readhttp://en.wikibooks.org/wiki/Clojure_Programming#Clojure_for_Common_L..., > > but it hasn't helped me. > > > > In LISP: > > > > * (defun fact (n) (cond ((= 1 n) 1)(t (* n (fact (- n > 1)))))) > > FACT > > * (fact 10) > > 3628800 > > > > that is Common LISP, but what the hell; in Portable > Standard LISP it > > would have been identical except 'de' instead > of 'defun'; in Scheme > > it's a little different: > > > > > (define (fact n) (cond ((= n 1) 1)(#t (* n (fact > (- n 1)))))) > > > (fact 10) > > > > 3628800 > > > > But the family resemblance is there... So, let's > try it in Clojure: > > > > user=> (defun fact (n) (cond ((= n 1) 1) (t (* n > (fact (- n 1)))))) > > java.lang.Exception: Unable to resolve symbol: defun > in this context > > user=> (de fact (n) ( cond ((= n 1) 1) (t (* n > (fact (- n 1)))))) > > java.lang.Exception: Unable to resolve symbol: de in > this context > > user=> (def fact (n) ( cond ((= n 1) 1) (t (* n > (fact (- n 1)))))) > > java.lang.Exception: Too many arguments to def > > user=> (defn fact [n] (cond ((= n 1) 1)(t (* n > (fact (- n 1)))))) > > java.lang.Exception: Unable to resolve symbol: t in > this context > > user=> (defn fact [n](cond ((= n 1) 1)(#t (* n > (fact (- n 1)))))) > > java.lang.Exception: No dispatch macro for: t > > user=> (defn fact [n](cond ((= n 1) 1)(#true (* n > (fact (- n 1)))))) > > java.lang.Exception: No dispatch macro for: t > > user=> (defn fact [n] (cond ((= n 1) 1)(true (* n > (fact (- n 1)))))) > > #'user/fact > > > > OK, what's with the funny square brackets? A > sequence of forms > > enclosed in square brackets is a vector, not a list. > Why is the > > arglist for a function a vector? For now let's > accept that it is, and > > pass on. > > > > user=> (fact 10) > > java.lang.ClassCastException: java.lang.Boolean cannot > be cast to > > clojure.lang.IFn > > > > OK, so that doesn't work. As Zaphod memorably put > it, 'hey, what is > > truth, man?' Good question: > > > > user=> (true? 'true) > > true > > user=> (true? true) > > true > > user=> (true? t) > > java.lang.Exception: Unable to resolve symbol: t in > this context > > user=> (true? 't) > > false > > user=> (def t 'true) > > #'user/t > > user=> (true? t) > > true > > > > OK, now we know the truth, surely we can write a valid > fact? > > > > user=> (defn fact [n] (cond ((= n 1) 1)('true > (* n (fact (- n 1)))))) > > #'user/fact > > user=> (fact 10) > > java.lang.ClassCastException: java.lang.Boolean cannot > be cast to > > clojure.lang.IFn > > user=> (defn fact [n] (cond ((= n 1) 1)((true? > 'true) (* n (fact (- n > > 1)))))) > > #'user/fact > > user=> (fact 10) > > java.lang.ClassCastException: java.lang.Boolean cannot > be cast to > > clojure.lang.IFn > > > > OK, it looks like whatever's causing the break > isn't the guard on the > > second cond branch. Let's for a moment try > something that's purely > > boolean: > > > > user=> (defn band [l] (cond ((nil? l) true)((true? > (car l))(band (cdr > > l))))) > > java.lang.Exception: Unable to resolve symbol: cdr in > this context > > > > No CDR? It's LISP, but it can't fetch the > contents of the decrement > > register? fifty years of LISP history tossed into the > dirt. So if the > > CDR isn't called the CDR, what is it called (and > what's the CDADR > > called)? > > > > user=> (defn band [l] (cond ((nil? l) true)((true? > (first l))(band > > (rest l))))) > > #'user/band > > user=> (band '(true true true)) > > java.lang.ClassCastException: java.lang.Boolean cannot > be cast to > > clojure.lang.IFn > > > > OK, can we write any function at all that works? > > > > user=> (defn square [n] (* n n)) > > #'user/square > > user=> (square 4) > > 16 > > > > Fine, so recurse up from that: > > > > user=> (defn power [n m] (cond ((= m 0) 1)(true (* > n (power n (- m > > 1)))))) > > #'user/power > > user=> (power 2 2) > > java.lang.ClassCastException: java.lang.Boolean cannot > be cast to > > clojure.lang.IFn > > > > Arrrrggghhh... > > > > Getting LISP to work seamlessly inside a Java > environment with easy > > intercalling between LISP and Java is a very big win, > and potentially > > knocks things like JScheme and Armed Bear Common LISP > into a cocked > > hat... > > > > But it would be nice to be able to get started! > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. 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