private Z3Expr MkCoercion(Z3Expr t, AppFreeCanUnn unn, UnionEmbedding te)
{
Z3Expr unbox;
//// If the union contains string, then it cannot contain other strings.
var test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.String), t, out unbox);
if (test != null)
{
return(test.Ite(Context, unbox, DefaultMember.Item2));
}
ITypeEmbedding tep;
Z3Expr coercions = DefaultMember.Item2;
foreach (var s in unn.NonRangeMembers)
{
if (s.Kind != SymbolKind.BaseCnstSymb)
{
continue;
}
test = te.MkTestAndUnbox(s, t, out unbox);
Contract.Assert(test != null);
tep = Owner.GetEmbedding(unbox.Sort);
switch (tep.Kind)
{
case TypeEmbeddingKind.Enum:
coercions = test.And(Context, unbox.Eq(Context, tep.MkGround(s, null))).Ite(
Context,
MkGround(s, null),
coercions);
break;
case TypeEmbeddingKind.Singleton:
coercions = test.Ite(
Context,
MkGround(s, null),
coercions);
break;
default:
throw new NotImplementedException();
}
}
return(coercions);
}
private Z3Expr MkCoercion(Z3Expr t, AppFreeCanUnn unn, UnionEmbedding te)
{
Z3BoolExpr test;
Z3Expr unboxed;
ITypeEmbedding ubxTE;
var coercions = DefaultMember.Item2;
foreach (var s in unn.NonRangeMembers)
{
test = te.MkTestAndUnbox(s, t, out unboxed);
Contract.Assert(test != null);
ubxTE = Owner.GetEmbedding(unboxed.FuncDecl.Range);
test = test.And(Context, ubxTE.MkGround(s, null).Eq(Context, unboxed));
coercions = test.Ite(Context, MkGround(s, null), coercions);
}
return(coercions);
}
private Z3Expr MkCoercion(Z3Expr t, AppFreeCanUnn unn, UnionEmbedding te)
{
Z3Expr unbox;
//// If the union contains real, then it cannot contain other integral numerics.
var test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.Real), t, out unbox);
if (test != null)
{
return(test.Ite(
Context,
MkCoercion(unbox, unn, (RealEmbedding)Owner.GetEmbedding(BaseSortKind.Real)),
DefaultMember.Item2));
}
//// If the union contains int, then it cannot contain other integral numerics.
test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.Integer), t, out unbox);
if (test != null)
{
return(test.Ite(
Context,
MkCoercion(unbox, unn, (IntegerEmbedding)Owner.GetEmbedding(BaseSortKind.Integer)),
DefaultMember.Item2));
}
//// Otherwise unn may contain subsorts of Integer or integer ranges.
//// First handle the base subsorts
var coercions = DefaultMember.Item2;
test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.Natural), t, out unbox);
if (test != null)
{
coercions = test.Ite(
Context,
MkCoercion(unbox, unn, (NaturalEmbedding)Owner.GetEmbedding(BaseSortKind.Natural)),
coercions);
}
test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.PosInteger), t, out unbox);
if (test != null)
{
coercions = test.Ite(
Context,
MkCoercion(unbox, unn, (PosIntegerEmbedding)Owner.GetEmbedding(BaseSortKind.PosInteger)),
coercions);
}
test = te.MkTestAndUnbox(Index.SymbolTable.GetSortSymbol(BaseSortKind.NegInteger), t, out unbox);
if (test != null)
{
coercions = test.Ite(
Context,
MkCoercion(unbox, unn, (NegIntegerEmbedding)Owner.GetEmbedding(BaseSortKind.NegInteger)),
coercions);
}
//// Additionally, there may be integer ranges.
Z3BoolExpr[] tests;
Z3Expr[] unboxeds;
ITypeEmbedding tep;
foreach (var kv in unn.RangeMembers)
{
tests = te.MkTestAndUnbox(kv.Key, kv.Value, t, out unboxeds);
for (int i = 0; i < tests.Length; ++i)
{
test = tests[i];
unbox = unboxeds[i];
tep = Owner.GetEmbedding(unbox.Sort);
switch (tep.Kind)
{
case TypeEmbeddingKind.IntRange:
coercions = test.Ite(
Context,
MkCoercion(unbox, unn, (IntRangeEmbedding)tep),
coercions);
break;
case TypeEmbeddingKind.Singleton:
coercions = test.Ite(
Context,
MkCoercion(unbox, unn, (SingletonEmbedding)tep),
coercions);
break;
default:
throw new NotImplementedException();
}
}
}
return(coercions);
}
private Z3Expr MkCoercion(Z3Expr t, AppFreeCanUnn unn, UnionEmbedding te)
{
return(CreationFun.Apply());
}