added -optimize option to compiler.

5 files changed, 485 insertions, 58 deletions

diff --git a/Binaries/DafnyRuntime.cs b/Binaries/DafnyRuntime.cs
index fd680a0b..7d3799d8 100644
--- a/Binaries/DafnyRuntime.cs
+++ b/Binaries/DafnyRuntime.cs
@@ -4,39 +4,430 @@ using System.Numerics;
 namespace Dafny

 {

   using System.Collections.Generic;

+// set this option if you want to use System.Collections.Immutable and if you know what you're doing.

+#if DAFNY_USE_SYSTEM_COLLECTIONS_IMMUTABLE

+  using System.Collections.Immutable;

+  using System.Linq;

 

   public class Set<T>

   {

-    Dictionary<T, bool> dict;

-    Set(Dictionary<T, bool> d) {

+    readonly ImmutableHashSet<T> setImpl;

+    Set(ImmutableHashSet<T> d) {

+      this.setImpl = d;

+    }

+    public static readonly Set<T> Empty = new Set<T>(ImmutableHashSet<T>.Empty);

+    public static Set<T> FromElements(params T[] values) {

+      return FromElements((IEnumerable<T>)values);

+    }

+    public static Set<T> FromElements(IEnumerable<T> values) {

+      var d = ImmutableHashSet<T>.Empty.ToBuilder();

+      foreach (T t in values)

+        d.Add(t);

+      return new Set<T>(d.ToImmutable());

+    }

+    public static Set<T> FromCollection(ICollection<T> values) {

+      var d = ImmutableHashSet<T>.Empty.ToBuilder();

+      foreach (T t in values)

+        d.Add(t);

+      return new Set<T>(d.ToImmutable());

+    }

+    public int Length {

+      get { return this.setImpl.Count; }

+    }

+    public long LongLength {

+      get { return this.setImpl.Count; }

+    }

+    public IEnumerable<T> Elements {

+      get {

+        return this.setImpl;

+      }

+    }

+    /// <summary>

+    /// This is an inefficient iterator for producing all subsets of "this".  Each set returned is the same

+    /// Set<T> object (but this Set<T> object is fresh; in particular, it is not "this").

+    /// </summary>

+    public IEnumerable<Set<T>> AllSubsets {

+      get {

+        // Start by putting all set elements into a list

+        var elmts = new List<T>();

+        elmts.AddRange(this.setImpl);

+        var n = elmts.Count;

+        var which = new bool[n];

+        var s = ImmutableHashSet<T>.Empty.ToBuilder();

+        while (true) {

+          yield return new Set<T>(s.ToImmutable());

+          // "add 1" to "which", as if doing a carry chain.  For every digit changed, change the membership of the corresponding element in "s".

+          int i = 0;

+          for (; i < n && which[i]; i++) {

+            which[i] = false;

+            s.Remove(elmts[i]);

+          }

+          if (i == n) {

+            // we have cycled through all the subsets

+            break;

+          }

+          which[i] = true;

+          s.Add(elmts[i]);

+        }

+      }

+    }

+    public bool Equals(Set<T> other) {

+        return this.setImpl.Equals(other.setImpl);

+    }

+    public override bool Equals(object other) {

+        var otherSet = other as Set<T>;

+        return otherSet != null && Equals(otherSet);

+    }

+    public override int GetHashCode() {

+      var hashCode = 1;

+      foreach (var t in this.setImpl) {

+        hashCode = hashCode * (t.GetHashCode()+3);

+      }

+      return hashCode;

+    }

+    public override string ToString() {

+      var s = "{";

+      var sep = "";

+      foreach (var t in this.setImpl) {

+        s += sep + t.ToString();

+        sep = ", ";

+      }

+      return s + "}";

+    }

+    public bool IsProperSubsetOf(Set<T> other) {

+        return IsProperSubsetOf(other);

+    }

+    public bool IsSubsetOf(Set<T> other) {

+        return IsSubsetOf(other);

+    }

+    public bool IsSupersetOf(Set<T> other) {

+      return other.IsSupersetOf(this);

+    }

+    public bool IsProperSupersetOf(Set<T> other) {

+      return other.IsProperSupersetOf(this);

+    }

+    public bool IsDisjointFrom(Set<T> other) {

+      ImmutableHashSet<T> a, b;

+      if (this.setImpl.Count < other.setImpl.Count) {

+        a = this.setImpl; b = other.setImpl;

+      } else {

+        a = other.setImpl; b = this.setImpl;

+      }

+      foreach (T t in a) {

+        if (b.Contains(t))

+          return false;

+      }

+      return true;

+    }

+    public bool Contains(T t) {

+      return this.setImpl.Contains(t);

+    }

+    public Set<T> Union(Set<T> other) {

+        return new Set<T>(this.setImpl.Union(other.setImpl));

+    }

+    public Set<T> Intersect(Set<T> other) {

+      return new Set<T>(this.setImpl.Intersect(other.setImpl));

+    }

+    public Set<T> Difference(Set<T> other) {

+        return new Set<T>(this.setImpl.Except(other.setImpl));

+    }

+  }

+  public partial class MultiSet<T>

+  {

+

+    readonly ImmutableDictionary<T, int> dict;

+    MultiSet(ImmutableDictionary<T, int> d) {

       dict = d;

     }

+    public static readonly MultiSet<T> Empty = new MultiSet<T>(ImmutableDictionary<T, int>.Empty);

+    public static MultiSet<T> FromElements(params T[] values) {

+      var d = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in values) {

+        var i = 0;

+        if (!d.TryGetValue(t, out i)) {

+          i = 0;

+        }

+        d[t] = i + 1;

+      }

+      return new MultiSet<T>(d.ToImmutable());

+    }

+    public static MultiSet<T> FromCollection(ICollection<T> values) {

+      var d = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in values) {

+        var i = 0;

+        if (!d.TryGetValue(t, out i)) {

+          i = 0;

+        }

+        d[t] = i + 1;

+      }

+      return new MultiSet<T>(d.ToImmutable());

+    }

+    public static MultiSet<T> FromSeq(Sequence<T> values) {

+      var d = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in values.Elements) {

+        var i = 0;

+        if (!d.TryGetValue(t, out i)) {

+          i = 0;

+        }

+        d[t] = i + 1;

+      }

+      return new MultiSet<T>(d.ToImmutable());

+    }

+    public static MultiSet<T> FromSet(Set<T> values) {

+      var d = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in values.Elements) {

+        d[t] = 1;

+      }

+      return new MultiSet<T>(d.ToImmutable());

+    }

+

+    public bool Equals(MultiSet<T> other) {

+      return other.IsSubsetOf(this) && this.IsSubsetOf(other);

+    }

+    public override bool Equals(object other) {

+      return other is MultiSet<T> && Equals((MultiSet<T>)other);

+    }

+    public override int GetHashCode() {

+      var hashCode = 1;

+      foreach (var kv in dict) {

+        var key = kv.Key.GetHashCode();

+        key = (key << 3) | (key >> 29) ^ kv.Value.GetHashCode();

+        hashCode = hashCode * (key + 3);

+      }

+      return hashCode;

+    }

+    public override string ToString() {

+      var s = "multiset{";

+      var sep = "";

+      foreach (var kv in dict) {

+        var t = kv.Key.ToString();

+        for (int i = 0; i < kv.Value; i++) {

+          s += sep + t.ToString();

+          sep = ", ";

+        }

+      }

+      return s + "}";

+    }

+    public bool IsProperSubsetOf(MultiSet<T> other) {

+      return !Equals(other) && IsSubsetOf(other);

+    }

+    public bool IsSubsetOf(MultiSet<T> other) {

+      foreach (T t in dict.Keys) {

+        if (!other.dict.ContainsKey(t) || other.dict[t] < dict[t])

+          return false;

+      }

+      return true;

+    }

+    public bool IsSupersetOf(MultiSet<T> other) {

+      return other.IsSubsetOf(this);

+    }

+    public bool IsProperSupersetOf(MultiSet<T> other) {

+      return other.IsProperSubsetOf(this);

+    }

+    public bool IsDisjointFrom(MultiSet<T> other) {

+      foreach (T t in dict.Keys) {

+        if (other.dict.ContainsKey(t))

+          return false;

+      }

+      foreach (T t in other.dict.Keys) {

+        if (dict.ContainsKey(t))

+          return false;

+      }

+      return true;

+    }

+    public bool Contains(T t) {

+      return dict.ContainsKey(t);

+    }

+    public MultiSet<T> Union(MultiSet<T> other) {

+      if (dict.Count == 0)

+        return other;

+      else if (other.dict.Count == 0)

+        return this;

+        var r = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in dict.Keys) {

+        var i = 0;

+        if (!r.TryGetValue(t, out i)) {

+          i = 0;

+        }

+        r[t] = i + dict[t];

+      }

+      foreach (T t in other.dict.Keys) {

+        var i = 0;

+        if (!r.TryGetValue(t, out i)) {

+          i = 0;

+        }

+        r[t] = i + other.dict[t];

+      }

+      return new MultiSet<T>(r.ToImmutable());

+    }

+    public MultiSet<T> Intersect(MultiSet<T> other) {

+      if (dict.Count == 0)

+        return this;

+      else if (other.dict.Count == 0)

+        return other;

+      var r = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in dict.Keys) {

+        if (other.dict.ContainsKey(t)) {

+          r[t] = other.dict[t] < dict[t] ? other.dict[t] : dict[t];

+        }

+      }

+      return new MultiSet<T>(r.ToImmutable());

+    }

+    public MultiSet<T> Difference(MultiSet<T> other) { // \result == this - other

+      if (dict.Count == 0)

+        return this;

+      else if (other.dict.Count == 0)

+        return this;

+      var r = ImmutableDictionary<T, int>.Empty.ToBuilder();

+      foreach (T t in dict.Keys) {

+        if (!other.dict.ContainsKey(t)) {

+          r[t] = dict[t];

+        } else if (other.dict[t] < dict[t]) {

+          r[t] = dict[t] - other.dict[t];

+        }

+      }

+      return new MultiSet<T>(r.ToImmutable());

+    }

+    public IEnumerable<T> Elements {

+      get {

+        foreach (T t in dict.Keys) {

+          int n;

+          dict.TryGetValue(t, out n);

+          for (int i = 0; i < n; i ++) {

+            yield return t;

+          }

+        }

+      }

+    }

+  }

+

+  public partial class Map<U, V>

+  {

+    readonly ImmutableDictionary<U, V> dict;

+    Map(ImmutableDictionary<U, V> d) {

+      dict = d;

+    }

+    public static readonly Map<U, V> Empty = new Map<U, V>(ImmutableDictionary<U, V>.Empty);

+    public static Map<U, V> FromElements(params Pair<U, V>[] values) {

+      var d = ImmutableDictionary<U, V>.Empty.ToBuilder();

+      foreach (Pair<U, V> p in values) {

+        d[p.Car] = p.Cdr;

+      }

+      return new Map<U, V>(d.ToImmutable());

+    }

+    public static Map<U, V> FromCollection(List<Pair<U, V>> values) {

+      var d = ImmutableDictionary<U, V>.Empty.ToBuilder();

+      foreach (Pair<U, V> p in values) {

+        d[p.Car] = p.Cdr;

+      }

+      return new Map<U, V>(d.ToImmutable());

+    }

+    public int Length {

+      get { return dict.Count; }

+    }

+    public long LongLength {

+      get { return dict.Count; }

+    }

+    public bool Equals(Map<U, V> other) {

+      foreach (U u in dict.Keys) {

+        V v1, v2;

+        if (!dict.TryGetValue(u, out v1)) {

+          return false; // this shouldn't happen

+        }

+        if (!other.dict.TryGetValue(u, out v2)) {

+          return false; // other dictionary does not contain this element

+        }

+        if (!v1.Equals(v2)) {

+          return false;

+        }

+      }

+      foreach (U u in other.dict.Keys) {

+        if (!dict.ContainsKey(u)) {

+          return false; // this shouldn't happen

+        }

+      }

+      return true;

+    }

+    public override bool Equals(object other) {

+      return other is Map<U, V> && Equals((Map<U, V>)other);

+    }

+    public override int GetHashCode() {

+      var hashCode = 1;

+      foreach (var kv in dict) {

+        var key = kv.Key.GetHashCode();

+        key = (key << 3) | (key >> 29) ^ kv.Value.GetHashCode();

+        hashCode = hashCode * (key + 3);

+      }

+      return hashCode;

+    }

+    public override string ToString() {

+      var s = "map[";

+      var sep = "";

+      foreach (var kv in dict) {

+        s += sep + kv.Key.ToString() + " := " + kv.Value.ToString();

+        sep = ", ";

+      }

+      return s + "]";

+    }

+    public bool IsDisjointFrom(Map<U, V> other) {

+      foreach (U u in dict.Keys) {

+        if (other.dict.ContainsKey(u))

+          return false;

+      }

+      foreach (U u in other.dict.Keys) {

+        if (dict.ContainsKey(u))

+          return false;

+      }

+      return true;

+    }

+    public bool Contains(U u) {

+      return dict.ContainsKey(u);

+    }

+    public V Select(U index) {

+      return dict[index];

+    }

+    public Map<U, V> Update(U index, V val) {

+      return new Map<U, V>(dict.SetItem(index, val));

+    }

+    public IEnumerable<U> Domain {

+      get {

+        return dict.Keys;

+      }

+    }

+  }

+#else // !def DAFNY_USE_SYSTEM_COLLECTIONS_IMMUTABLE

+  public class Set<T>

+  {

+    HashSet<T> set;

+    Set(HashSet<T> s) {

+      this.set = s;

+    }

     public static Set<T> Empty {

       get {

-        return new Set<T>(new Dictionary<T, bool>(0));

+        return new Set<T>(new HashSet<T>());

       }

     }

     public static Set<T> FromElements(params T[] values) {

-      Dictionary<T, bool> d = new Dictionary<T, bool>(values.Length);

+      var s = new HashSet<T>();

       foreach (T t in values)

-        d[t] = true;

-      return new Set<T>(d);

+        s.Add(t);

+      return new Set<T>(s);

     }

     public static Set<T> FromCollection(ICollection<T> values) {

-      Dictionary<T, bool> d = new Dictionary<T, bool>();

+      HashSet<T> s = new HashSet<T>();

       foreach (T t in values)

-        d[t] = true;

-      return new Set<T>(d);

+        s.Add(t);

+      return new Set<T>(s);

     }

     public int Length {

-      get { return dict.Count; }

+      get { return this.set.Count; }

     }

     public long LongLength {

-      get { return dict.Count; }

+      get { return this.set.Count; }

     }

     public IEnumerable<T> Elements {

       get {

-        return dict.Keys;

+        return this.set;

       }

     }

     /// <summary>

@@ -47,36 +438,36 @@ namespace Dafny
       get {

         // Start by putting all set elements into a list

         var elmts = new List<T>();

-        elmts.AddRange(dict.Keys);

+        elmts.AddRange(this.set);

         var n = elmts.Count;

         var which = new bool[n];

-        var s = new Set<T>(new Dictionary<T, bool>(0));

+        var s = new Set<T>(new HashSet<T>());

         while (true) {

           yield return s;

           // "add 1" to "which", as if doing a carry chain.  For every digit changed, change the membership of the corresponding element in "s".

           int i = 0;

           for (; i < n && which[i]; i++) {

             which[i] = false;

-            s.dict.Remove(elmts[i]);

+            s.set.Remove(elmts[i]);

           }

           if (i == n) {

             // we have cycled through all the subsets

             break;

           }

           which[i] = true;

-          s.dict.Add(elmts[i], true);

+          s.set.Add(elmts[i]);

         }

       }

     }

     public bool Equals(Set<T> other) {

-      return dict.Count == other.dict.Count && IsSubsetOf(other);

+      return this.set.Count == other.set.Count && IsSubsetOf(other);

     }

     public override bool Equals(object other) {

       return other is Set<T> && Equals((Set<T>)other);

     }

     public override int GetHashCode() {

       var hashCode = 1;

-      foreach (var t in dict.Keys) {

+      foreach (var t in this.set) {

         hashCode = hashCode * (t.GetHashCode()+3);

       }

       return hashCode;

@@ -84,20 +475,20 @@ namespace Dafny
     public override string ToString() {

       var s = "{";

       var sep = "";

-      foreach (var t in dict.Keys) {

+      foreach (var t in this.set) {

         s += sep + t.ToString();

         sep = ", ";

       }

       return s + "}";

     }

     public bool IsProperSubsetOf(Set<T> other) {

-      return dict.Count < other.dict.Count && IsSubsetOf(other);

+      return this.set.Count < other.set.Count && IsSubsetOf(other);

     }

     public bool IsSubsetOf(Set<T> other) {

-      if (other.dict.Count < dict.Count)

+      if (other.set.Count < this.set.Count)

         return false;

-      foreach (T t in dict.Keys) {

-        if (!other.dict.ContainsKey(t))

+      foreach (T t in this.set) {

+        if (!other.set.Contains(t))

           return false;

       }

       return true;

@@ -109,66 +500,66 @@ namespace Dafny
       return other.IsProperSubsetOf(this);

     }

     public bool IsDisjointFrom(Set<T> other) {

-      Dictionary<T, bool> a, b;

-      if (dict.Count < other.dict.Count) {

-        a = dict; b = other.dict;

+      HashSet<T> a, b;

+      if (this.set.Count < other.set.Count) {

+        a = this.set; b = other.set;

       } else {

-        a = other.dict; b = dict;

+        a = other.set; b = this.set;

       }

-      foreach (T t in a.Keys) {

-        if (b.ContainsKey(t))

+      foreach (T t in a) {

+        if (b.Contains(t))

           return false;

       }

       return true;

     }

     public bool Contains(T t) {

-      return dict.ContainsKey(t);

+      return this.set.Contains(t);

     }

     public Set<T> Union(Set<T> other) {

-      if (dict.Count == 0)

+      if (this.set.Count == 0)

         return other;

-      else if (other.dict.Count == 0)

+      else if (other.set.Count == 0)

         return this;

-      Dictionary<T, bool> a, b;

-      if (dict.Count < other.dict.Count) {

-        a = dict; b = other.dict;

+      HashSet<T> a, b;

+      if (this.set.Count < other.set.Count) {

+        a = this.set; b = other.set;

       } else {

-        a = other.dict; b = dict;

+        a = other.set; b = this.set;

       }

-      Dictionary<T, bool> r = new Dictionary<T, bool>();

-      foreach (T t in b.Keys)

-        r[t] = true;

-      foreach (T t in a.Keys)

-        r[t] = true;

+      var r = new HashSet<T>();

+      foreach (T t in b)

+        r.Add(t);

+      foreach (T t in a)

+        r.Add(t);

       return new Set<T>(r);

     }

     public Set<T> Intersect(Set<T> other) {

-      if (dict.Count == 0)

+      if (this.set.Count == 0)

         return this;

-      else if (other.dict.Count == 0)

+      else if (other.set.Count == 0)

         return other;

-      Dictionary<T, bool> a, b;

-      if (dict.Count < other.dict.Count) {

-        a = dict; b = other.dict;

+      HashSet<T> a, b;

+      if (this.set.Count < other.set.Count) {

+        a = this.set; b = other.set;

       } else {

-        a = other.dict; b = dict;

+        a = other.set; b = this.set;

       }

-      var r = new Dictionary<T, bool>();

-      foreach (T t in a.Keys) {

-        if (b.ContainsKey(t))

-          r.Add(t, true);

+      var r = new HashSet<T>();

+      foreach (T t in a) {

+        if (b.Contains(t))

+          r.Add(t);

       }

       return new Set<T>(r);

     }

     public Set<T> Difference(Set<T> other) {

-      if (dict.Count == 0)

+      if (this.set.Count == 0)

         return this;

-      else if (other.dict.Count == 0)

+      else if (other.set.Count == 0)

         return this;

-      var r = new Dictionary<T, bool>();

-      foreach (T t in dict.Keys) {

-        if (!other.dict.ContainsKey(t))

-          r.Add(t, true);

+      var r = new HashSet<T>();

+      foreach (T t in this.set) {

+        if (!other.set.Contains(t))

+          r.Add(t);

       }

       return new Set<T>(r);

     }

@@ -447,6 +838,7 @@ namespace Dafny
       }

     }

   }

+#endif

   public class Sequence<T>

   {

     T[] elmts;

diff --git a/Source/Dafny/DafnyOptions.cs b/Source/Dafny/DafnyOptions.cs
index a6827d5f..125ab11e 100644
--- a/Source/Dafny/DafnyOptions.cs
+++ b/Source/Dafny/DafnyOptions.cs
@@ -55,6 +55,7 @@ namespace Microsoft.Dafny
     public bool ignoreAutoReq = false;

     public bool AllowGlobals = false;

     public bool CountVerificationErrors = true;

+    public bool Optimize = false;

 

     protected override bool ParseOption(string name, Bpl.CommandLineOptionEngine.CommandLineParseState ps) {

       var args = ps.args;  // convenient synonym

@@ -180,6 +181,11 @@ namespace Microsoft.Dafny
           return true;

         }

 

+        case "optimize": {

+            Optimize = true;

+            return true;

+        }

+

         default:

           break;

       }

@@ -270,6 +276,12 @@ namespace Microsoft.Dafny
                     of verification errors.

                 1 (default) - If preprocessing succeeds, set exit code to the number of

                               verification errors.

+  /optimize     Produce optimized C# code, meaning:

+                  - selects optimized C# prelude by passing 

+                    /define:DAFNY_USE_SYSTEM_COLLECTIONS_IMMUTABLE to csc.exe (requires 

+                    System.Collections.Immutable.dll in the source directory to successfully 

+                    compile).

+                  - passes /optimize flag to csc.exe.

 ");

       base.Usage();  // also print the Boogie options

     }

diff --git a/Source/DafnyDriver/DafnyDriver.cs b/Source/DafnyDriver/DafnyDriver.cs
index a769b829..cf464754 100644
--- a/Source/DafnyDriver/DafnyDriver.cs
+++ b/Source/DafnyDriver/DafnyDriver.cs
@@ -15,6 +15,8 @@ namespace Microsoft.Dafny
   using System.Collections.Generic;

   using System.Diagnostics.Contracts;

   using System.IO;

+  using System.Reflection;

+

   using Microsoft.Boogie;

   using Bpl = Microsoft.Boogie;

 

@@ -330,7 +332,7 @@ namespace Microsoft.Dafny
       }

       else

       {

-        var provider = CodeDomProvider.CreateProvider("CSharp");

+        var provider = CodeDomProvider.CreateProvider("CSharp", new Dictionary<string, string> { { "CompilerVersion", "v4.0" } });

         var cp = new System.CodeDom.Compiler.CompilerParameters();

         cp.GenerateExecutable = hasMain;

         if (DafnyOptions.O.RunAfterCompile) {

@@ -344,6 +346,15 @@ namespace Microsoft.Dafny
         }

         cp.CompilerOptions = "/debug /nowarn:0164 /nowarn:0219";  // warning CS0164 complains about unreferenced labels, CS0219 is about unused variables

         cp.ReferencedAssemblies.Add("System.Numerics.dll");

+        cp.ReferencedAssemblies.Add("System.Core.dll");

+        cp.ReferencedAssemblies.Add("System.dll");

+

+        if (DafnyOptions.O.Optimize) {

+          var libPath = Path.GetDirectoryName(dafnyProgramName);

+          cp.CompilerOptions += string.Format(" /optimize /define:DAFNY_USE_SYSTEM_COLLECTIONS_IMMUTABLE /lib:{0}", libPath);

+          cp.ReferencedAssemblies.Add("System.Collections.Immutable.dll");

+          cp.ReferencedAssemblies.Add("System.Runtime.dll");

+        }

 

         var cr = provider.CompileAssemblyFromSource(cp, csharpProgram);

         var assemblyName = Path.GetFileName(cr.PathToAssembly);

diff --git a/Test/irondafny0/optimize0.dfy b/Test/irondafny0/optimize0.dfy
new file mode 100644
index 00000000..865d8707
--- /dev/null
+++ b/Test/irondafny0/optimize0.dfy
@@ -0,0 +1,6 @@
+// RUN: %dafny /compile:3 /optimize /print:"%t.print" /dprint:"%t.dprint" "%s" > "%t"

+// RUN: %diff "%s.expect" "%t"

+

+method Main() {

+    print "o hai!";

+}

diff --git a/Test/irondafny0/optimize0.dfy.expect b/Test/irondafny0/optimize0.dfy.expect
new file mode 100644
index 00000000..6b3e13c5
--- /dev/null
+++ b/Test/irondafny0/optimize0.dfy.expect
@@ -0,0 +1,6 @@
+

+Dafny program verifier finished with 2 verified, 0 errors

+Program compiled successfully

+Running...

+

+o hai!
\ No newline at end of file