7
的ML大家我有此片段的代碼:嵌套局部聲明在NJ
local
helper(f, i, j) = local
fun NTimesF(f, n:int) =
if n = 1 then fn (x) => f(x)
else fn (x) => f(NTimesF(f, n - 1)(x));
in
if(i <= j) then NTimesF(f, i) :: helper(f, (i+1), j)
else []
end
in
fun compList f n = helper(f, 1, n);
end;
我需要編寫程序接收一些函數f和整數n和產生的函數列表如[F1, F2,... FN] < - FN是函數n次,但每一次的組成我收到一個錯誤:
- stdIn:1.1-2.9 Error: syntax error: deleting LOCAL ID LPAREN
stdIn:2.10-2.14 Error: syntax error: deleting COMMA ID COMMA
stdIn:2.16-2.25 Error: syntax error: deleting RPAREN EQUALOP LOCAL
stdIn:3.6-3.17 Error: syntax error: deleting FUN ID
stdIn:4.6-4.10 Error: syntax error: deleting IF ID
stdIn:4.15-4.22 Error: syntax error: deleting THEN FN
stdIn:4.27-4.31 Error: syntax error: deleting DARROW ID
stdIn:5.6-5.13 Error: syntax error: deleting ELSE FN
stdIn:5.16-5.22 Error: syntax error: deleting RPAREN DARROW ID
stdIn:6.8-7.8 Error: syntax error: deleting IN IF
stdIn:7.17-7.29 Error: syntax error: deleting THEN ID
stdIn:8.6-8.13 Error: syntax error: deleting ELSE LBRACKET RBRACKET
stdIn:9.8-11.5 Error: syntax error: deleting END IN FUN
看來,我的嵌套局部聲明是錯誤的,可以有人請解釋一下爲什麼?
@ sepp2k:非常感謝,我將兩個「本地」更改爲兩個「讓」,無論如何,我收到4個第一個錯誤,可能是別的嗎? – rookie 2010-11-28 14:33:39