author | haftmann |
Mon, 16 Nov 2009 11:03:14 +0100 | |
changeset 33707 | 68841fb382e0 |
parent 30226 | 2f4684e2ea95 |
child 34156 | 3a7937841585 |
permissions | -rw-r--r-- |
28421 | 1 |
structure Example = |
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struct |
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fun foldl f a [] = a |
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| foldl f a (x :: xs) = foldl f (f a x) xs; |
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fun rev xs = foldl (fn xsa => fn x => x :: xsa) [] xs; |
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fun list_case f1 f2 (a :: lista) = f2 a lista |
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| list_case f1 f2 [] = f1; |
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datatype 'a queue = AQueue of 'a list * 'a list; |
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33707
68841fb382e0
dropped obsolete documentation; updated generated sources
haftmann
parents:
30226
diff
changeset
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val empty : 'a queue = AQueue ([], []); |
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fun dequeue (AQueue ([], [])) = (NONE, AQueue ([], [])) |
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| dequeue (AQueue (xs, y :: ys)) = (SOME y, AQueue (xs, ys)) |
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| dequeue (AQueue (v :: va, [])) = |
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let |
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val y :: ys = rev (v :: va); |
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in |
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(SOME y, AQueue ([], ys)) |
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end; |
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fun enqueue x (AQueue (xs, ys)) = AQueue (x :: xs, ys); |
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end; (*struct Example*) |