diff options
| author |  rustanleino <unknown> | 2011-03-26 08:54:54 +0000 |
|---|---|---|
| committer | rustanleino <unknown> | 2011-03-26 08:54:54 +0000 |
| commit | 53281904797b0d78e18a79cc2d140df7ba4b9086 (patch) | |
| tree | 6f1b098b301fc8e6594c22199fb94a257164b7d5 /Binaries | |
| parent | cd3946b053478afdf7258ce23e34b9ccf51189b5 (diff) | |
Dafny: added "choose" operator on sets
Diffstat (limited to 'Binaries')
| -rw-r--r-- | Binaries/DafnyPrelude.bpl | 11 | ||||
| -rw-r--r-- | Binaries/DafnyRuntime.cs | 6 |
2 files changed, 17 insertions, 0 deletions
diff --git a/Binaries/DafnyPrelude.bpl b/Binaries/DafnyPrelude.bpl index 1ef8aea7..646b16f1 100644 --- a/Binaries/DafnyPrelude.bpl +++ b/Binaries/DafnyPrelude.bpl @@ -80,6 +80,10 @@ function Set#Disjoint<T>(Set T, Set T) returns (bool); axiom (forall<T> a: Set T, b: Set T :: { Set#Disjoint(a,b) }
Set#Disjoint(a,b) <==> (forall o: T :: {a[o]} {b[o]} !a[o] || !b[o]));
+function Set#Choose<T>(Set T, TickType) returns (T);
+axiom (forall<T> a: Set T, tick: TickType :: { Set#Choose(a, tick) }
+ a != Set#Empty() ==> a[Set#Choose(a, tick)]);
+
// ---------------------------------------------------------------
// -- Axiomatization of sequences --------------------------------
// ---------------------------------------------------------------
@@ -347,6 +351,13 @@ axiom (forall h: HeapType, k: HeapType :: { $HeapSucc(h,k) } $HeapSucc(h,k) ==> (forall o: ref :: { read(k, o, alloc) } read(h, o, alloc) ==> read(k, o, alloc)));
// ---------------------------------------------------------------
+// -- Non-determinism --------------------------------------------
+// ---------------------------------------------------------------
+
+type TickType;
+var $Tick: TickType;
+
+// ---------------------------------------------------------------
// -- Arithmetic -------------------------------------------------
// ---------------------------------------------------------------
diff --git a/Binaries/DafnyRuntime.cs b/Binaries/DafnyRuntime.cs index f32cc85a..63cca64a 100644 --- a/Binaries/DafnyRuntime.cs +++ b/Binaries/DafnyRuntime.cs @@ -117,6 +117,12 @@ namespace Dafny }
return new Set<T>(r);
}
+ public T Choose() {
+ foreach (T t in dict.Keys) {
+ // return the first one
+ return t;
+ }
+ }
}
public class Sequence<T>
{
|