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1 | (* Copyright (C) 2009 Matthew Fluet. |
2 | * Copyright (C) 2004-2007 Henry Cejtin, Matthew Fluet, Suresh | |
3 | * Jagannathan, and Stephen Weeks. | |
4 | * | |
5 | * MLton is released under a BSD-style license. | |
6 | * See the file MLton-LICENSE for details. | |
7 | *) | |
8 | ||
9 | functor IntSize (S: INT_SIZE_STRUCTS): INT_SIZE = | |
10 | struct | |
11 | ||
12 | open S | |
13 | ||
14 | datatype t = T of {bits: Bits.t} | |
15 | ||
16 | fun bits (T {bits, ...}) = bits | |
17 | ||
18 | fun compare (s, s') = Bits.compare (bits s, bits s') | |
19 | ||
20 | val {equals, ...} = Relation.compare compare | |
21 | ||
22 | fun isValidSize (i: int) = | |
23 | (1 <= i andalso i <= 32) orelse i = 64 | |
24 | ||
25 | val sizes: Bits.t list = | |
26 | Vector.toList | |
27 | (Vector.keepAllMap | |
28 | (Vector.tabulate (65, fn i => if isValidSize i | |
29 | then SOME (Bits.fromInt i) | |
30 | else NONE), | |
31 | fn i => i)) | |
32 | ||
33 | fun make i = T {bits = i} | |
34 | ||
35 | val allVector = Vector.tabulate (65, fn i => | |
36 | if isValidSize i | |
37 | then SOME (make (Bits.fromInt i)) | |
38 | else NONE) | |
39 | ||
40 | fun fromBits (b: Bits.t): t = | |
41 | case Vector.sub (allVector, Bits.toInt b) handle Subscript => NONE of | |
42 | NONE => Error.bug (concat ["IntSize.fromBits: strange int size: ", Bits.toString b]) | |
43 | | SOME s => s | |
44 | ||
45 | val all = List.map (sizes, fromBits) | |
46 | ||
47 | val memoize: (t -> 'a) -> t -> 'a = | |
48 | fn f => | |
49 | let | |
50 | val v = Vector.map (allVector, fn opt => Option.map (opt, f)) | |
51 | in | |
52 | fn T {bits = b, ...} => valOf (Vector.sub (v, Bits.toInt b)) | |
53 | end | |
54 | ||
55 | end |