1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
\DOC rev_itlist2
\TYPE {rev_itlist2 : ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c}
\SYNOPSIS
Applies a paired function between adjacent elements of 2 lists.
\KEYWORDS
list.
\DESCRIBE
{itlist2 f ([x1;...;xn],[y1;...;yn]) z} returns
{
f xn yn ( ... (f x2 y2 (f x1 y1 z))...)}.
}
\noindent It returns {z} if both lists are empty.
\FAILURE
Fails if the two lists are of different lengths.
\EXAMPLE
This takes a `dot product' of two vectors of integers:
{
# let dot v w = rev_itlist2 (fun x y z -> x * y + z) v w 0;;
val dot : int list -> int list -> int = <fun>
# dot [1;2;3] [4;5;6];;
val it : int = 32
}
\SEEALSO
itlist, rev_itlist, rev_itlist2, end_itlist, uncurry.
\ENDDOC
|
