5.8 Ï¢Áۥꥹ¥È

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'((pine . cones)
  (oak . acorns)
  (maple . seeds))

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((a . 1) ("b" 2 3))

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'((rose red) (lily white) (buttercup yellow))

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Function: assoc key alist

¤³¤Î´Ø¿ô¤Ï¡¢alistÆâ¤Îkey¤ËÂФ¹¤ëºÇ½é¤ÎÏ¢ÁÛ¤òÊÖ¤¹¡£ key¤ÈÏ¢Áۥꥹ¥È¤Î³ÆÍ×ÁǤȤÎÈæ³Ó¤Ë¤Ï¡¢ equal¡Êsee Equality Predicates¡Ë¤òÍѤ¤¤ë¡£ alist¤ÎÃæ¤ËCAR¤¬key¤Ëequal¤Ç¤¢¤ëÏ¢ÁÛ¤¬ ¸ºß¤·¤Ê¤±¤ì¤Ð¡¢nil¤òÊÖ¤¹¡£ ¤¿¤È¤¨¤Ð¡¢¤Ä¤®¤Î¤È¤ª¤ê¡£

(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
     ⇒ ((pine . cones) (oak . acorns) (maple . seeds))
(assoc 'oak trees)
     ⇒ (oak . acorns)
(cdr (assoc 'oak trees))
     ⇒ acorns
(assoc 'birch trees)
     ⇒ nil

¤Ä¤®¤Ï¡¢¥­¡¼¤ÈÃͤ¬¥·¥ó¥Ü¥ë¤Ç¤Ï¤Ê¤¤Îã¡£

(setq needles-per-cluster
      '((2 "Austrian Pine" "Red Pine")
        (3 "Pitch Pine")
        (5 "White Pine")))

(cdr (assoc 3 needles-per-cluster))
     ⇒ ("Pitch Pine")
(cdr (assoc 2 needles-per-cluster))
     ⇒ ("Austrian Pine" "Red Pine")

´Ø¿ôassoc-ignore-representation¤Èassoc-ignore-case¤Ï assoc¤Ë»÷¤Æ¤¤¤Þ¤¹¤¬¡¢ ¤½¤ì¤é¤ÏÈæ³Ó¤Ëcompare-strings¤ò»È¤¦ÅÀ¤¬°Û¤Ê¤ê¤Þ¤¹¡£ See Text Comparison¡£

Function: rassoc value alist

¤³¤Î´Ø¿ô¤Ï¡¢alist¤ÎÃæ¤Çvalue¤òÃͤȤ¹¤ëºÇ½é¤ÎÏ¢ÁÛ¤òÊÖ¤¹¡£ alist¤ÎÃæ¤ËCDR¤¬value¤Ëequal¤Ç¤¢¤ëÏ¢ÁÛ¤¬ ¸ºß¤·¤Ê¤±¤ì¤Ð¡¢nil¤òÊÖ¤¹¡£

rassoc¤Ïassoc¤Ë»÷¤Æ¤¤¤ë¤¬¡¢ alist¤Î³ÆÏ¢ÁÛ¤ÎCAR¤Î¤«¤ï¤ê¤ËCDR¤òÈæ³Ó¤¹¤ëÅÀ¤¬°Û¤Ê¤ë¡£ »ØÄꤷ¤¿ÃͤËÂФ¹¤ë¥­¡¼¤òõ¤¹¡Øassoc¤ÎµÕ±é»»¡Ù¤È¹Í¤¨¤ë¤³¤È¤¬¤Ç¤­¤ë¡£

Function: assq key alist

¤³¤Î´Ø¿ô¤Ï¡¢alistÆâ¤Îkey¤ËÂФ¹¤ëºÇ½é¤ÎÏ¢ÁÛ¤òÊÖ¤¹¤È¤¤¤¦°ÕÌ£¤Ç assoc¤Ë»÷¤Æ¤¤¤ë¤¬¡¢equal¤Î¤«¤ï¤ê¤Ëeq¤ÇÈæ³Ó¤¹¤ë¡£ alistÆâ¤ÎÏ¢ÁÛ¤ÎCAR¤¬key¤Ëeq¤Ç¤¢¤ë¤â¤Î¤¬Â¸ºß¤·¤Ê¤¤¤È¡¢ assq¤Ïnil¤òÊÖ¤¹¡£ ¤³¤Î´Ø¿ô¤Ïassoc¤è¤ê¿ÍѤµ¤ì¤ë¡£ ¤È¤¤¤¦¤Î¤Ï¡¢eq¤Ïequal¤è¤ê¹â®¤Ç¤¢¤ê¡¢ ¤Û¤È¤ó¤É¤ÎÏ¢Áۥꥹ¥È¤Ç¤Ï¥­¡¼¤È¤·¤Æ¥·¥ó¥Ü¥ë¤ò»È¤¦¤«¤é¤Ç¤¢¤ë¡£

(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
     ⇒ ((pine . cones) (oak . acorns) (maple . seeds))
(assq 'pine trees)
     ⇒ (pine . cones)

°ìÊý¤Ç¡¢¥­¡¼¤¬¥·¥ó¥Ü¥ë¤Ç¤Ï¤Ê¤¤Ï¢Áۥꥹ¥È¤Ç¤Ï¡¢ assq¤Ï¡¢Ä̾ͭÍѤǤϤʤ¤¡£

(setq leaves
      '(("simple leaves" . oak)
        ("compound leaves" . horsechestnut)))

(assq "simple leaves" leaves)
     ⇒ nil
(assoc "simple leaves" leaves)
     ⇒ ("simple leaves" . oak)

Function: rassq value alist

¤³¤Î´Ø¿ô¤Ï¡¢alist¤ÎÃæ¤Çvalue¤òÃͤȤ¹¤ëºÇ½é¤ÎÏ¢ÁÛ¤òÊÖ¤¹¡£ alist¤ÎÃæ¤ËCDR¤¬value¤Ëeq¤Ç¤¢¤ëÏ¢ÁÛ¤¬ ¸ºß¤·¤Ê¤±¤ì¤Ð¡¢nil¤òÊÖ¤¹¡£

rassq¤Ïassq¤Ë»÷¤Æ¤¤¤ë¤¬¡¢ alist¤Î³ÆÏ¢ÁÛ¤ÎCAR¤Î¤«¤ï¤ê¤ËCDR¤òÈæ³Ó¤¹¤ëÅÀ¤¬°Û¤Ê¤ë¡£ »ØÄꤷ¤¿ÃͤËÂФ¹¤ë¥­¡¼¤òõ¤¹¡Øassq¤ÎµÕ±é»»¡Ù¤È¹Í¤¨¤ë¤³¤È¤¬¤Ç¤­¤ë¡£

¤¿¤È¤¨¤Ð¤Ä¤®¤Î¤È¤ª¤ê¡£

(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))

(rassq 'acorns trees)
     ⇒ (oak . acorns)
(rassq 'spores trees)
     ⇒ nil

rassq¤Ç¤Ï¡¢ Í×ÁǤÎCDR¤ÎCAR¤Ë³ÊǼ¤µ¤ì¤¿Ãͤòõ¤»¤Ê¤¤¤³¤È¤ËÃí°Õ¡£

(setq colors '((rose red) (lily white) (buttercup yellow)))

(rassq 'white colors)
     ⇒ nil

¤³¤Î¾ì¹ç¡¢Ï¢ÁÛ(lily white)¤ÎCDR¤Ï¡¢ ¥·¥ó¥Ü¥ëwhite¤Ç¤Ï¤Ê¤¯¥ê¥¹¥È(white)¤Ç¤¢¤ë¡£ Ï¢ÁÛ¤ò¥É¥Ã¥ÈÂе­Ë¡¤Ç½ñ¤¯¤È¤³¤ì¤¬ÌÀ³Î¤Ë¤Ê¤ë¡£

(lily white) ≡ (lily . (white))

Function: assoc-default key alist test default

¤³¤Î´Ø¿ô¤Ï¡¢key¤Ë°ìÃפ¹¤ë¤â¤Î¤òalist¤«¤éõ¤¹¡£ alist¤Î³ÆÍ×ÁǤˤĤ¤¤Æ¡¢¡Ê¥¢¥È¥à¤Ê¤é¤Ð¡ËÍ×ÁǤÈkey¤ò¡¢ ¤¢¤ë¤¤¤Ï¡¢¡Ê¥³¥ó¥¹¤Ê¤é¤Ð¡ËÍ×ÁǤÎCAR¤Èkey¤òÈæ³Ó¤¹¤ë¡£ Èæ³Ó¤Ë¤Ï¤³¤ì¤é¤ò2¤Ä¤Î°ú¿ô¤È¤·¤Ætest¤ò¸Æ¤Ó½Ð¤¹¡£ °ú¿ô¤òÅϤ¹½ç½ø¤Ï¤³¤Î½ç¤Ê¤Î¤Ç¡¢ Àµµ¬É½¸½¡Êsee Regexp Search¡Ë¤ò¼ý¤á¤¿Ï¢Áۥꥹ¥È¤ËÂФ·¤Æ string-match¤ò»È¤¦¤ÈÍ­±×¤Ê·ë²Ì¤òÆÀ¤é¤ì¤ë¡£ test¤ò¾Êά¤·¤¿¤ênil¤Ç¤¢¤ë¤È¡¢Èæ³Ó¤Ë¤Ïequal¤òÍѤ¤¤ë¡£

¾å¤Î¾ò·ï¤ÇÏ¢Áۥꥹ¥È¤ÎÍ×ÁǤ¬key¤Ë°ìÃפ¹¤ë¤Ê¤é¤Ð¡¢ assoc-default¤Ï¤½¤ÎÍ×ÁǤ˴ð¤Å¤¯ÃͤòÊÖ¤¹¡£ Í×ÁǤ¬¥³¥ó¥¹¤Ê¤é¤ÐÃͤÏÍ×ÁǤÎCDR¡£ ¤µ¤â¤Ê¤±¤ì¤Ð¡¢Ìá¤êÃͤÏdefault¡£

key¤Ë°ìÃפ¹¤ëÏ¢Áۥꥹ¥È¤ÎÍ×ÁǤ¬Â¸ºß¤·¤Ê¤±¤ì¤Ð¡¢ assoc-default¤Ïnil¤òÊÖ¤¹¡£

Function: copy-alist alist

¤³¤Î´Ø¿ô¤Ï¡¢alist¤ò2¥ì¥Ù¥ë¤Î¿¼¤µ¤Þ¤Ç¥³¥Ô¡¼¤·¤¿¤â¤Î¤òÊÖ¤¹¡£ ³ÆÏ¢ÁÛ¤´¤È¤Ë¿·¤¿¤Ê¥³¥Ô¡¼¤òºî¤ë¤Î¤Ç¡¢ ¿·¤¿¤ÊÏ¢Áۥꥹ¥È¤ÎÏ¢ÁÛ¤òÊѹ¹¤·¤Æ¤â¡¢¤â¤È¤ÎÏ¢Áۥꥹ¥È¤ÏÊѹ¹¤·¤Ê¤¤¡£

(setq needles-per-cluster
      '((2 . ("Austrian Pine" "Red Pine"))
        (3 . ("Pitch Pine"))

        (5 . ("White Pine"))))
⇒
((2 "Austrian Pine" "Red Pine")
 (3 "Pitch Pine")
 (5 "White Pine"))

(setq copy (copy-alist needles-per-cluster))
⇒
((2 "Austrian Pine" "Red Pine")
 (3 "Pitch Pine")
 (5 "White Pine"))

(eq needles-per-cluster copy)
     ⇒ nil
(equal needles-per-cluster copy)
     ⇒ t
(eq (car needles-per-cluster) (car copy))
     ⇒ nil
(cdr (car (cdr needles-per-cluster)))
     ⇒ ("Pitch Pine")

(eq (cdr (car (cdr needles-per-cluster)))
    (cdr (car (cdr copy))))
     ⇒ t

¤³¤ÎÎã¤Ï¡¢copy-alist¤Ë¤è¤ê¡¢ ¥³¥Ô¡¼¤ÎÏ¢ÁÛ¤òÊѹ¹¤·¤Æ¾¤Î¤â¤Î¤Ë¤Ê¤¼±Æ¶Á¤·¤Ê¤¤¤«¤ò¼¨¤¹¡£

(setcdr (assq 3 copy) '("Martian Vacuum Pine"))
(cdr (assq 3 needles-per-cluster))
     ⇒ ("Pitch Pine")