public static CatFxnType Infer(CatExpr f)
{
if (!Config.gbTypeChecking)
{
return(null);
}
if (f.Count == 0)
{
if (Config.gbVerboseInference)
{
Log("type is ( -> )");
}
return(CatFxnType.Create("( -> )"));
}
else if (f.Count == 1)
{
Function x = f[0];
if (Config.gbVerboseInference)
{
OutputInferredType(x.GetFxnType());
}
return(x.GetFxnType());
}
else
{
Function x = f[0];
CatFxnType ft = x.GetFxnType();
if (Config.gbVerboseInference)
{
Log("initial term = " + x.GetName() + " : " + x.GetFxnTypeString());
}
for (int i = 1; i < f.Count; ++i)
{
if (ft == null)
{
return(ft);
}
Function y = f[i];
if (Config.gbVerboseInference)
{
Log("Composing accumulated terms with next term");
string s = "previous terms = { ";
for (int j = 0; j < i; ++j)
{
s += f[j].GetName() + " ";
}
Log(s + "} : " + ft.ToString());
Log("next term = " + y.GetName() + " : " + y.GetFxnTypeString());
}
ft = ComposeTypes(ft, y.GetFxnType());
if (ft == null)
{
return(null);
}
}
return(ft);
}
}
public CatFxnType LocalComposeTypes(CatFxnType left, CatFxnType right)
{
// Make sure that the variables on the left function and the variables
// on the right function are different
CatVarRenamer renamer = new CatVarRenamer();
left = renamer.Rename(left.AddImplicitRhoVariables());
renamer.ResetNames();
right = renamer.Rename(right.AddImplicitRhoVariables());
Log("==");
Log("Composing : " + left.ToString());
Log("with : " + right.ToString());
Log("Adding constraints");
Relation rLeft = FxnTypeToRelation(left);
Relation rRight = FxnTypeToRelation(right);
//TODO: remove
//rLeft.UnrollRecursiveRelations();
//rRight.UnrollRecursiveRelations();
Relation result = new Relation(rLeft.GetLeft(), rRight.GetRight());
AddTopLevelConstraints(rLeft.GetRight(), rRight.GetLeft());
AddConstraint(CreateVar("result$"), result);
Log("Constraints");
ComputeConstraintLists();
LogConstraints();
Log("Unifiers");
ComputeUnifiers();
foreach (string sVar in GetConstrainedVars())
{
Constraint u = GetUnifierFor(sVar);
Log("var: " + sVar + " = " + u);
}
Log("Composed Type");
Constraint c = GetResolvedUnifierFor("result$");
if (!(c is Relation))
throw new Exception("Resolved type is not a relation");
// TODO: remove
// Relation r = c as Relation;
// r.RollupRecursiveRelations();
CatKind k = ConstraintToCatKind(c);
CatFxnType ft = k as CatFxnType;
Log("raw type : " + ft.ToString());
Log("pretty type : " + ft.ToPrettyString());
Log("==");
CheckConstraintQueueEmpty();
// Check if the relation was valid, and thus the function type
if (!ft.IsValid())
throw new Exception("invalid function type: " + ft.ToString());
return ft;
}
public CatFxnType LocalComposeTypes(CatFxnType left, CatFxnType right)
{
// Make sure that the variables on the left function and the variables
// on the right function are different
CatVarRenamer renamer = new CatVarRenamer();
left = renamer.Rename(left.AddImplicitRhoVariables());
renamer.ResetNames();
right = renamer.Rename(right.AddImplicitRhoVariables());
Log("==");
Log("Composing : " + left.ToString());
Log("with : " + right.ToString());
Log("Adding constraints");
Relation rLeft = FxnTypeToRelation(left);
Relation rRight = FxnTypeToRelation(right);
//TODO: remove
//rLeft.UnrollRecursiveRelations();
//rRight.UnrollRecursiveRelations();
Relation result = new Relation(rLeft.GetLeft(), rRight.GetRight());
AddTopLevelConstraints(rLeft.GetRight(), rRight.GetLeft());
AddConstraint(CreateVar("result$"), result);
Log("Constraints");
ComputeConstraintLists();
LogConstraints();
Log("Unifiers");
ComputeUnifiers();
foreach (string sVar in GetConstrainedVars())
{
Constraint u = GetUnifierFor(sVar);
Log("var: " + sVar + " = " + u);
}
Log("Composed Type");
Constraint c = GetResolvedUnifierFor("result$");
if (!(c is Relation))
{
throw new Exception("Resolved type is not a relation");
}
// TODO: remove
// Relation r = c as Relation;
// r.RollupRecursiveRelations();
CatKind k = ConstraintToCatKind(c);
CatFxnType ft = k as CatFxnType;
Log("raw type : " + ft.ToString());
Log("pretty type : " + ft.ToPrettyString());
Log("==");
CheckConstraintQueueEmpty();
// Check if the relation was valid, and thus the function type
if (!ft.IsValid())
{
throw new Exception("invalid function type: " + ft.ToString());
}
return(ft);
}
