Closure
又叫static scope,或直觀點(diǎn)叫bag。
一個(gè)袋子,里面的環(huán)境等等都在這個(gè)袋子里。
(define bank-account
??(let ((balance 10))
????(lambda (n)
??????(set! balance (+ balance n))
????? balance)))
(bank-account 20)?????; donating 20 dollars
;Value: 30
(bank-account -25)?????; withdrawing 25 dollars
;Value: 5
轉(zhuǎn)載于:https://www.cnblogs.com/zbjxb/archive/2012/12/29/3495772.html
總結(jié)