HCoop / hcoop / debian / mlton.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f918cf1 CE |
1 | (* Copyright (C) 1999-2006 Henry Cejtin, Matthew Fluet, Suresh |
| 2 | * Jagannathan, and Stephen Weeks. | |
| 3 | * | |
| 4 | * MLton is released under a BSD-style license. | |
| 5 | * See the file MLton-LICENSE for details. | |
| 6 | *) | |
| 7 | ||
| 8 | functor PolyCache(): POLY_CACHE = | |
| 9 | struct | |
| 10 | ||
| 11 | datatype ('a, 'b) t = T of {equal: ('a * 'a) -> bool, | |
| 12 | elts: ('a * 'b ref) list ref} | |
| 13 | ||
| 14 | fun fromList | |
| 15 | ||
| 16 | fun new equal = T{equal = equal, elts = ref []} | |
| 17 | ||
| 18 | fun all(T{elts, ...}) = List.map(!elts, fn (x, y) => (x, !y)) | |
| 19 | ||
| 20 | fun peekR(T{equal, elts = ref l}, x) = | |
| 21 | case List.keepFirst(l, fn (x', _) => equal(x, x')) of | |
| 22 | NONE => NONE | |
| 23 | | SOME(_, y) => SOME y | |
| 24 | ||
| 25 | fun peek(c, x) = | |
| 26 | case peekR(c, x) of | |
| 27 | NONE => NONE | |
| 28 | | SOME r => SOME(!r) | |
| 29 | ||
| 30 | fun lookup cx = Option.project(peek cx) | |
| 31 | ||
| 32 | fun addNew(T{elts = r as ref l, ...}, x, y) = | |
| 33 | r := (x, ref y) :: l | |
| 34 | ||
| 35 | fun set(c, x, y) = | |
| 36 | case peekR(c, x) of | |
| 37 | NONE => addNew(c, x, y) | |
| 38 | | SOME r => r := y | |
| 39 | ||
| 40 | fun getOrAdd(c, x, th) = | |
| 41 | case peek(c, x) of | |
| 42 | NONE => let val y = th() | |
| 43 | in addNew(c, x, y) ; y | |
| 44 | end | |
| 45 | | SOME y => y | |
| 46 | ||
| 47 | fun eq(T{elts=r, ...}, T{elts=r', ...}) = r = r' | |
| 48 | ||
| 49 | end | |
| 50 | ||
| 51 | structure PolyCache = PolyCache() |