RE: [Axiom-developer] Boot

[Gabriel Dos Reis]

On Tue, 21 Nov 2006, Page, Bill wrote:

| Gaby,
|
| If you plan to go ahead with the proposed documentation of
| "new boot" (aka. SHOE) I would be delighted to help. Perhaps
| you have said before, but could you please explain how to
| call SHOE from the command line?

The current document script uses bootsys (the translator for
SHOE).  Currently, we do not install bootsys, nor is it
part of AXIOMsys.  Ideally, I would like to see bootsys replace
the old Boot translator.

As an intermediate solution, we could install bootsys, then
you would translate foo.boot with either

  document --tag=boot --mode=translaye bootsys foo.boot

and that will produce foo.clisp in the same directory, or
you can say directly

   echo '(boottran::boottocl "foo.boot")' | bootsys

If you say

   echo '(boottran::boottoclc "foo.boot")' | bootsys

then the Boot code is included as comment -- but this is is
wiki stuff, who cares?

| What I would like to do is to provide a environment in the
| Axiom Wiki, e.g.
|
|   \begin{shoe}
|   ....
|   \end{shoe}
|
| where we can compile examples of SHOE code. There is already
| such an environment for boot
|
|   \begin{boot}
|   ....
|   \end{boot}
|
| See
|
| http://wiki.axiom-developer.org/BootProgramming

That is very interesting.

| I am very interested in your comment about the relationship
| between SHOE and Haskell.

Basically, SHOE provides a way to define algebraic datatype and way to
deconstruct values of such type.  (There is no type-checking at the
moment, but it would not be hard to implement).  Unlike Haskell,
Shoe does not support (yet) function definition by separate
equations: you have to use a single case expression (which is morally
what Core Haskell does).

   structure BinTree ==
       Nil                         -- the null node
       Node(Val, BinTree, BinTree) -- or a value and a pair of
                                   -- binary tree

   depth x ==
      case x of
          Nil => 0
          Node(x, l, r) => 1 + MAX(depth l, depth r)

   depth Node(Nil, Node(2, Nil, Nil), Nil)


Notice how the compilation of the body of the structure BinTree
is almost like one would have expected (from a naive translation
point of view).  If properly augmented, Shoe can serve as a good
support for a class on implementation of function languages along the
lines of the now classic "The Implementation of Functional
Proramming Languages" (out of print, but you can download it from the
website)

  http://research.microsoft.com/~simonpj/Papers/slpj-book-1987/index.htm


-- Gaby