EoPL reading (52) 2.2 An Abstraction for Inductive Data Type

scheme EoPL

UT 大事ですが、パラで EoPL なナニも進める方向で。
# 休みなんでこっち方面に稼動がなかなか向けれない
とりあえずテキストに例示されているソレを確認。とりあえず bintree から。

(use gauche.test)

(add-load-path ".")
(load "define-datatype")

(test-start "define-datatype")
(test-section "bintree")

(define-datatype bintree bintree?
  (leaf-node
   (datum number?))
  (interior-node
   (key symbol?)
   (left bintree?)
   (right bintree?)))

(define tree-a (interior-node 'a (leaf-node 2) (leaf-node 3)))
(define tree-b (interior-node 'b (leaf-node -1) tree-a))
(define tree-c (interior-node 'c tree-b (leaf-node 1)))

(test* "tree-a'"
       '(interior-node a (leaf-node 2) (leaf-node 3))
       tree-a)

(test* "tree-b"
       '(interior-node b (leaf-node -1) (interior-node a
						       (leaf-node 2)
						       (leaf-node 3)))
       tree-b)

(test* "tree-c"
       '(interior-node c
		       (interior-node b
				      (leaf-node -1)
				      (interior-node a
						     (leaf-node 2)

						     (leaf-node 3)))
		       (leaf-node 1))
       tree-c)

(test* "predicate (1)"
       #t
       (bintree? tree-a))
(test* "predicate (2)"
       #t
       (bintree? tree-b))
(test* "predicate (3)"
       #t
       (bintree? tree-c))

(test-end)

試験実行。

$ make
Testing define-datatype ...                                      passed.
rms@debian:~/chroot.home/1.programming/2.EoPL/3.2.2/1.bintree$ cat test.log
define-datatype.scm version J3 2002-01-02 10:55
Testing define-datatype =======================================================
<bintree>----------------------------------------------------------------------
test tree-a', expects (interior-node a (leaf-node 2) (leaf-node 3)) ==> ok
test tree-b, expects (interior-node b (leaf-node -1) (interior-node a (leaf-node 2) (leaf-node 3))) ==> ok
test tree-c, expects (interior-node c (interior-node b (leaf-node -1) (interior-node a (leaf-node 2) (leaf-node 3))) (leaf-node 1)) ==> ok
test predicate (1), expects #t ==> ok
test predicate (2), expects #t ==> ok
test predicate (3), expects #t ==> ok
passed.
$

なんかタグ付けなリストになっている模様。てか、define-datatype の何処でこれをセットしてるのか、と言いつつソース見てみたら以下な部分?

       (define Type-name
         (cons '(Variant-name ...)
           '((Variant-name Field-name ...) ...)))

や、なんか違うぞ、と言いつつ gosh にて確認。

gosh> interior-node
#<closure interior-node>
gosh> leaf-node
#<closure leaf-node>
gosh> bintree
((leaf-node interior-node) (leaf-node datum) (interior-node key left right))
gosh>

最後のは何だろ。ってか、正に上記 Type-name が戻すナニか。なら、上記の interior-node だの leaf-node だのが戻す手続きは何だ、というとおそらくは

       (define Variant-name

なソレなのか。やっぱきちんとソース読めって事ッスか?