public void AddFunction(string functionName, IfsType functionType)
{
if (functionsTypes.ContainsKey(functionName))
{
throw new Exception($"Function {functionName} already exists in current scope");
}
functionsTypes.Add(functionName, functionType);
}
public void AddVar(string varName, IfsType varType)
{
if (varType.Name == "function")
{
if (functionsTypes.ContainsKey(varName))
{
throw new Exception($"Function {varName} already exists in current scope");
}
functionsTypes.Add(varName, varType);
}
if (varsTypes.ContainsKey(varName))
{
throw new Exception($"Variable {varName} already exists in current scope");
}
varsTypes.Add(varName, varType);
}
public void ScopeVarOrFuncTypeChangedHandler(string oldTypeName, IfsType newType)
{
if (this.Text != "TYPE" || oldTypeName != NodeType.Name)
{
if (NodeType.Name == "function")
{
fsType nodeTyped = NodeType as fsType;
for (int i = 0; i < nodeTyped.Types.Count; i++)
{
if (nodeTyped.Types[i].Name == oldTypeName)
{
nodeTyped.Types[i] = newType;
}
}
}
return;
}
NodeType = newType;
}
private void UnifyWrapper(ref IfsType t1, ref IfsType t2, fsScope scope)
{
bool isT1FromScope = false;
bool isT2FromScope = false;
string t1ScopeName = "";
string t1NameBeforeUnification = t1.Name;
string t2ScopeName = "";
string t2NameBeforeUnification = t2.Name;
if (t1 is fsTypeVar)
{
isT1FromScope = (t1 as fsTypeVar).IsFromScope;
t1ScopeName = (t1 as fsTypeVar).ScopeVarName;
}
if (t2 is fsTypeVar)
{
isT2FromScope = (t2 as fsTypeVar).IsFromScope;
t2ScopeName = (t2 as fsTypeVar).ScopeVarName;
}
Unify(ref t1, ref t2, scope);
if (isT1FromScope)
{
scope.ChangeVarOrFuncType(t1ScopeName, t1NameBeforeUnification, t1);
}
if (isT2FromScope)
{
scope.ChangeVarOrFuncType(t2ScopeName, t2NameBeforeUnification, t2);
}
}
private void Unify(ref IfsType t1, ref IfsType t2, fsScope scope)
{
if (t1.Name == "identity")
{
t1 = t2;
return;
}
if (t2.Name == "identity")
{
t2 = t1;
return;
}
IfsType t1Pruned = Prune(t1);
IfsType t2Pruned = Prune(t2);
if (t1Pruned.Name != "composite")
{
t1 = t1Pruned;
}
if (t2Pruned.Name != "composite")
{
t2 = t2Pruned;
}
if (t1 is fsTypeVar)
{
if (!t1.Equals(t2))
{
if (OccursInType(t1, t2))
{
throw new Exception("Recursive unification");
}
if (t2.Name == "composite")
{
(t1 as fsTypeVar).Instance = t2;
}
else
{
t1 = t2;
}
}
}
else if(t1 is fsType && t2 is fsTypeVar)
{
UnifyWrapper(ref t2, ref t1, scope);
}
else if (t1 is fsType && t2 is fsType)
{
fsType type1 = t1 as fsType;
fsType type2 = t2 as fsType;
if (type1.Name == "composite")
{
if (type2.Name != "composite")
{
UnifyWrapper(ref t2, ref t1, scope);
return;
}
List<IfsType> commonTypes = new List<IfsType>();
for (int i = 0; i < type1.Types.Count; i++)
{
for (int j = 0; j < type2.Types.Count; j++)
{
if (type1.Types[i].Equals(type2.Types[j]))
{
commonTypes.Add(type1.Types[i]);
}
}
}
if (commonTypes.Count < 1)
{
throw new Exception($"Cannot unify types {type1.Name} and {type2.Name}");
}
else if (commonTypes.Count == 0)
{
t1 = t2 = commonTypes[0];
}
else
{
fsTypeVar commonType = new fsTypeVar();
commonType.Instance = fsType.GetCompositeType(commonTypes);
t1 = t2 = commonType;
}
return;
}
if (type2.Name == "composite")
{
for (int i = 0; i < type2.Types.Count; i++)
{
if (type1.Equals(type2.Types[i]))
{
t1 = t2 = type1;
return;
}
}
throw new Exception($"Cannot unify types {type1.Name} and {type2.Name}");
}
if (!type1.Equals(type2))
{
throw new Exception($"Cannot unify types {type1.Name} and {type2.Name}");
}
if (type1.Name == "function")
{
if (type1.Types.Count == type2.Types.Count)
{
IfsType returningType = type2.Types[type2.Types.Count - 1];
for (int i = 0; i < type1.Types.Count - 1; i++)
{
IfsType t1Child = type1.Types[i];
IfsType t2Child = type2.Types[i];
string t2NameBeforeUnification = t2Child.Name;
//Changed !!!!!!!
UnifyWrapper(ref t2Child, ref t1Child, scope);
type1.Types[i] = t1Child;
type2.Types[i] = t2Child;
if (returningType.Name == t2NameBeforeUnification)
{
UnifyWrapper(ref returningType, ref t1Child, scope);
type1.Types[i] = returningType;
type2.Types[type2.Types.Count - 1] = t2Child;
}
}
}
else if (type1.Types.Count < type2.Types.Count)
{
int difference = type2.Types.Count - type1.Types.Count;
for (int i = 0; i < type1.Types.Count - 1; i++)
{
IfsType t1Child = type1.Types[i];
IfsType t2Child = type2.Types[i];
string t2NameBeforeUnification = t2Child.Name;
//Changed !!!!!!!
UnifyWrapper(ref t2Child, ref t1Child, scope);
type1.Types[i] = t1Child;
type2.Types[i] = t2Child;
for (int j = difference; j < type2.Types.Count; j++)
{
IfsType bufType = type2.Types[j];
if (bufType.Name == t2NameBeforeUnification)
{
UnifyWrapper(ref t1Child, ref bufType, scope);
type1.Types[i] = bufType;
type2.Types[j] = t2Child;
}
}
}
List<IfsType> rest = type2.Types.GetRange(type1.Types.Count - 1, difference + 1);
type1.Types[type1.Types.Count - 1] = fsType.GetFunctionType(rest);
t1 = t2 = type1;
}
else
{
throw new Exception($"Cannot unify types {type1.Name} and {type2.Name}");
}
}
}
else
{
throw new Exception($"Cannot unify types {t1.Name} and {t2.Name}");
}
}
private IfsType Prune(IfsType type)
{
fsTypeVar a;
if ((a = type as fsTypeVar)?.Instance != null)
{
a.Instance = Prune(a.Instance);
return a.Instance;
}
return type;
}
private bool OccursInTypeArray(IfsType type, List<IfsType> types)
{
foreach (var t in types)
{
if (OccursInType(type, t))
{
return true;
}
}
return false;
}
private bool OccursInType(IfsType t1, IfsType t2)
{
t2 = Prune(t2);
if (t2.Equals(t1))
{
return true;
}
else if (t2 is fsType)
{
return OccursInTypeArray(t1, (t2 as fsType).Types);
}
return false;
}
private IfsType InferBinaryOpType(ITree node, fsScope scope, IfsType availableType)
{
IfsType leftOperandType = Analyse(node.GetChild(0), scope);
IfsType rightOperandType = Analyse(node.GetChild(1), scope);
UnifyWrapper(ref leftOperandType, ref availableType, scope);
UnifyWrapper(ref rightOperandType, ref availableType, scope);
UnifyWrapper(ref leftOperandType, ref rightOperandType, scope);
return leftOperandType;
}
public void ChangeVarOrFuncType(string varName, string oldTypeName, IfsType newType)
{
ScopeVarOrFuncTypeChanged(oldTypeName, newType);
}
public fsTreeNode(IfsType type)
: base(new CommonToken(fsharp_ssParser.TYPE, type.Name))
{
this.Text = "TYPE";
this.NodeType = type;
}