On lisp ch18
- 1. 18. Destructurning Destructuring is a generalization of assignment.
- 2. Destructuring :朱 . 18.1 Destructuring on Lists destructuring 螳 list襯 destructruring 覯. 18.2 Other Structures dbind(destructuing-bind) 蟲 る 覓語, 覯″, 覦一, 蟲譟一牡襯 destructuring 覯. 18.3 Reference 語ろ伎るゼ destructuring 覯. 18.4 Matching 企Г豺 伎 if-match蟲(1, 2) 覦 る.
- 3. 18.1 Destructuring on Lists (assign) seq, setf 蠏(access) & (assign) destructuring-bind
- 4. Destructuring-bind CLTL2, Common Lisp destructurning-bind 襦 襷ろ襦襯 豢 螳.
- 5. Ex) destrucing-bind 貊螳 讌ъ讌 訖襷, 覲企 覈伎 . CLTL1 (let ((x (first lst)) (y (second lst)) (z (third lst))) (list x y z)) CLTL2 れ伎 (destructuring-bind (x y z) lst (list x y z))
- 6. Destructuring Destructuring CLTL1 Common Lisp 譟伎. 讌蠍 磯 覿襴螳 讌襷, destructuring-bind 襷ろ襦 襷り覲 襴 碁ゼ 覿襴る 貊企.
- 7. 18.2 Other Structures 襴ろ碁ゼ destructuring一 蟇 螳 . 蠏碁讌襷, 覲旧″ 螳豌伎 伎 . > (dbind (a (b . c) &rest d) '(1 "fribble" 2 3 4) (list a b c d)) (1 #f "ribble" (2 3 4))
- 8. 覓語願骸 覦燕 read-macro # - 覓語襯 蠍 CL-USER> (coerce "123" 'list) (#1 #2 #3) read-macro #( - 覯″磯ゼ 蠍 CL-USER> (vector 1 2 3) #(1 2 3) CL-USER> (make-array 3 :initial-contents '(1 2 3)) #(1 2 3) CL-USER> (make-array '(2 3) :initial-contents '((1 2 3) (4 5 6))) #2A((1 2 3) (4 5 6)) *print-array*
- 9. Dbind 讌蠍蟾讌 覺 襷ろ襦り骸 觜蟲覃, dbind 蠏覈螳 ｸ伎襷, Lisp 襦蠏碁覦 蟯 general lesson 願蠍一, 企至 讌 危 蠏語蟆 , 襷ろ襦 蟲 螻給 螳豺螳 .
- 10. Ex) Dbind (defmacro dbind (pat seq &body body) (let ((gseq (gensym))) `(let ((,gseq ,seq)) ,(dbind-ex (destruc pat gseq #'atom) body)))) dbind destructuring-bind豌 壱 譯殊伎 り 襯 詞 覈 る, 襯 覦
- 11. Ex) with- with-matrix 覦一伎 蠍磯 with-array 覦一伎 譬 蠍磯 with-struct 蟲譟一牡 prefix name 蠍磯
- 12. 18.3 Reference let symbol-macrolet朱 ル蟆 襷 朱, call-by-name 覯 destructuring 襷ろ襦襯 襷 .
- 13. ex) with-places (defmacro with-places (pat seq &body body) (let ((gseq (gensym))) `(let ((,gseq ,seq)) ,(wplac-ex (destruc pat gseq #'atom) body)))) Wplac-ex 企 dbind-ex 覃, let symbol-macrolet朱 覦.
- 14. 18.4 Matching destructuring 朱 企朱, 企Г豺 朱 destructuring企. ``企Г豺''企 企 覩碁ゼ 讌 螻 讌襷, 蠍一, 覲襯 螻 襭蟲譟磯ゼ 觜蟲, 螳螳 狩覃 覲 螳 蟆 覩誤蠍磯 .
- 15. 狩(Unification) 企Г豺螻 狩 るゴ. 企Г豺 覦, 狩 覦 X = Y X = 5 企Г豺 豌覯讌 殊碁 (Y螳 bind讌 蠍一) Erlang 狩 Y 5 螳 螳蟆. Prolog http://stackoverflow.com/questions/4442314/differences- between-pattern-matching-and-unification Unification pattern matching る危蟆.
- 16. Match 語襦 覦蟆 朱Μ 觜蟲 覲 螳 襦 襷れ 譴 (bindings). (match '(p ?x b ?y a) '(p ?y b c a)) ((?Y . C) (?X . ?Y)) ;; 襷れ cons襦 覓苦伎 T ;; 襷れ讌 れ朱 flag
- 17. Ex)match (defun match (x y &optional binds) (acond2 ((or (eql x y) (eql x '_) (eql y '_)) (values binds t)) ((binding x binds) (match it y binds)) ((binding y binds) (match x it binds)) ((varsym? x) (values (cons (cons x y) binds) t)) ((varsym? y) (values (cons (cons y x) binds) t)) ((and (consp x) (consp y) (match (car x) (car y) binds)) (match (cdr x) (cdr y) it)) (t (values nil nil))))
- 18. if-match ( 1 ) (defun abab (seq) (if-match (?x ?y ?x ?y) seq (values ?x ?y) nil)) match binding 伎 if-match 襯 蟲.
- 19. Ex) if-match ( 1 ) (defmacro if-match (pat seq then &optional else) `(aif2 (match ',pat ,seq) (let ,(mapcar #'(lambda (v) `(,v (binding ',v it))) (vars-in then #'atom)) ,then) ,else))
- 20. If-match ( 2 ).1 if-match(1) 讌ъ襷, 壱 覓 襷 殊 (觜) 企 螳 if-match(2) 蠍語襷, 貉危殊 襷 殊 . If-match 豌覯讌 語襦 れ伎る 蟆 朱 覲螳 企襦 る, 貉危 Match 蟯覲襯 蟆企 .
- 21. If-match ( 2 ).2 企 Quote蟆 , 螳 . 朱覲 quote 企襦 伎 .
- 22. Ex) if-match ( 2 ) (defmacro if-match2 (pat seq then &optional else) `(let ,(mapcar #'(lambda (v) `(,v ',(gensym))) (vars-in pat #'simple?)) (pat-match ,pat ,seq ,then ,else))) (defmacro pat-match (pat seq then else) (if (simple? pat) (match1 .. ---- A (with-gensym ---- B A れ 螻 B - gensym 企 bind讌 蠍一, binding 貊襯 燕
- 23. Ex) match1 (defun match1 (refs then else) (dbind ((pat expr) . rest) refs (cond ((gensym? pat) . -- A ((var? pat) .. -- B A : length-test B : binding
- 24. 394p - 244 ?x襯 螻 る? (if-match (?x . ?rest1) lst1 (if-match (?x . ?rest2) lst2 ?x)) 豢 19 with-answer螻, 24レ with-inference襦 願屋
- 25. 襷豺覃 螳? Destructuring , 覃 讌 match蟾讌 危ｴ覺. 襾語 レ 企 豌 蠍磯 襦蠏碁 る.