1Array.fold(3kaya)            Kaya module reference           Array.fold(3kaya)
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NAME

6       Array::fold - Fold an array.
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SYNOPSIS

9       b fold( b(a, b) f, [a] xs, b acc )
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ARGUMENTS

12       f The function to use
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14       xs The array
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16       acc The initial value for folding.
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DESCRIPTION

19       Applies  a  function across an array. For example, given a function sum
20       which adds two integers:
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23    total = fold(sum,[1,2,3,4,5],0);
24    putStrLn(String(total));
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26       This prints the sum of the values in the array [1,2,3,4,5]
27        The following example uses fold to calculate the final direction.
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30    data Direction = North | East | South | West;
31    data Turn = Left | Right;
32    Direction doTurn(Turn turn, Direction current) {
33        case turn of {
34            Left -> case current of {
35                North -> new = West;
36                | West -> new = South;
37                | South -> new = East;
38                | East -> new = North;
39            }
40            | Right -> case current of {
41                North -> new = East;
42                | West -> new = North;
43                | South -> new = West;
44                | East -> new = South;
45            }
46        }
47        return new;
48    }
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50    Void main() {
51        turns = [Left,Left,Left,Right,Right,Left,Right,Left,Left];
52        original = West;
53        final = fold(doTurn,turns,original);
54        // final = North
55    }
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AUTHORS

58       Kaya  standard  library  by  Edwin  Brady,  Chris  Morris  and   others
59       (kaya@kayalang.org). For further information see http://kayalang.org/
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LICENSE

62       The  Kaya  standard  library  is free software; you can redistribute it
63       and/or modify it under the terms  of  the  GNU  Lesser  General  Public
64       License  (version  2.1  or  any later version) as published by the Free
65       Software Foundation.
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68       Array.map (3kaya)
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72Kaya                             December 2010               Array.fold(3kaya)
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