As far as the bug goes, I still haven't tested the code, but here are a few fixes I just pushed, which may or may not be relevant:

   (def feval (expr (o env fenv*))
     (case type.expr
       cons  (fapply (feval car.expr env) cdr.expr env)
  -    sym   do.env.expr
  +    sym   (fenv-get env expr)
             expr))
  
   ; The 'applicative type is totally Kernel's idea.
   (def fapply (op args (o env fenv*))
     (case type.op
       fexpr        (rep.op env args)
  -    applicative  ((rep rep.op) env (map [feval _ env] args))
  +    applicative  (fapply unwrap.op (map [feval _ env] args) env)
                    (apply op (map [feval _ env] args))))
  
  ...
  
  +
  +; We use a singleton list so that an applicative can wrap an
  +; applicative. Using 'annotate does nothing to a value that's already
  +; of the given type.
  +
   (fdef wrap (fexpr)
  -  (annotate 'applicative fexpr))
  +  (annotate 'applicative list.fexpr))
  
   (fdef unwrap (applicative)
  -  rep.applicative)
  +  rep.applicative.0)
  +

Here's the link again: https://gist.github.com/778492

Another thing:

I'm guessing [that definition of quote] came from Kernel, but it's brilliant.

Well, I didn't (consciously) take that from Kernel. It's just what fexprs do, right?

  Needless to say, none of the examples in this book have been run on a computer.

  None of the programs in this monograph, needless to say, has been tested on a machine.

---

Update 15 hours later: yep, your version is right. A couple more gems in that Preface:

"..it hurts me to see the semantics of the repetitive construct

  while B do S

  whiledo(B, S)

I don't like to crack an egg with a sledgehammer, no matter how effective the sledgehammer..

Contrast the Alan Kay quote that says you should find the most complex construct you possibly need, and build everything in terms of it. (again my google fu is weak)

For the absence of a bibliography I offer neither explanation nor apology.

---

Contrast the Alan Kay quote that says you should find the most complex construct you possibly need, and build everything in terms of it. (again my google fu is weak)

If Alan Kay's the person to credit for OOP, I guess that doesn't surprise me. ^_^ A simple basis of complicated things is just fine. For instance, not all our lambdas actually need to be closures, but that doesn't stop us from reasoning about them as closures for the sake of reducing the number of concepts we're juggling.

The problem comes around when people forget how arbitrary any particular complicated basis is. XD I'm looking at you, "Arc needs OOP" threads.

So maybe the Dijkstra and Kay quotes are compatible, in a sense. Kay can be encouraging people to find appropriate foundations from which to implement concepts, and Dijkstra can be encouraging people to perceive the concept itself rather than taking its implementation for granted.

I guess I can't really say that without knowing more of the context of what Dijkstra and Kay believed. Still, a quote more opposite to Dijkstra's might be this one:

Beyond the primitive operators, which by definition can't be written in the language, the whole of the Arc spec will be written in Arc. As Abelson and Sussman say, programs must be written for people to read, and only incidentally for machines to execute. So if a language is any good, source code ought to be a better way to convey ideas than English prose.

- Paul Graham

"take the hardest and most profound thing you need to do, make it great, an [sic] then build every easier thing out of it."

---

My next questions was, why on earth call it a functional language? Why not just base everuything [sic] on FEXPRs and force evaluation on the receiving side when needed? I could never get a good answer, but the question was very helpful when it came time to invent Smalltalk, because this started a line of thought that said "take the hardest and most profound thing you need to do, make it great, an then build every easier thing out of it". That was the promise of LiSP and the lure of lambda--needed was a better "hardest and most profound" thing. Objects should be it.