public static IEnumerable<object> EvaluateTacnyExpression(ProofState state, Expression expr) {
Contract.Requires<ArgumentNullException>(state != null, "state");
Contract.Requires<ArgumentNullException>(expr != null, "expr");
if (expr is NameSegment) {
var ns = (NameSegment)expr;
if (state.HasLocalValue(ns.Name)) {
yield return state.GetLocalValue(ns.Name);
} else {
yield return ns;
}
} else if (expr is ApplySuffix) {
var aps = (ApplySuffix)expr;
if (state.IsTacticCall(aps)) {
var us = new UpdateStmt(aps.tok, aps.tok, new List<Expression>() { aps.Lhs },
new List<AssignmentRhs>() { new ExprRhs(aps) });
foreach (var item in ApplyNestedTactic(state, state.DafnyVars(), us).Select(x => x.GetGeneratedCode())) {
yield return item;
}
}
// rewrite the expression
if (aps.Lhs is ExprDotName) {
foreach (var item in EvaluateTacnyExpression(state, aps.Lhs)) {
if (item is Expression) {
yield return new ApplySuffix(aps.tok, (Expression)item, aps.Args);
} else {
Contract.Assert(false, "Unexpected ExprNotName case");
}
}
} else {
// try to evaluate as tacny expression
string sig = Util.GetSignature(aps);
// using reflection find all classes that extend EAtomic
var types =
Assembly.GetAssembly(typeof(EAtomic.EAtomic)).GetTypes().Where(t => t.IsSubclassOf(typeof(EAtomic.EAtomic)));
foreach (var type in types) {
var resolverInstance = Activator.CreateInstance(type) as EAtomic.EAtomic;
if (sig == resolverInstance?.Signature) {
//TODO: validate input countx
foreach (var item in resolverInstance?.Generate(aps, state))
yield return item;
}
// if we reached this point, rewrite the apply suffix
foreach (var item in EvaluateTacnyExpression(state, aps.Lhs)) {
if (!(item is NameSegment)) {
//TODO: warning
} else {
var argList = new List<Expression>();
foreach (var arg in aps.Args) {
foreach (var result in EvaluateTacnyExpression(state, arg)) {
if (result is Expression)
argList.Add(result as Expression);
else
argList.Add(Util.VariableToExpression(result as IVariable));
break;
}
}
yield return new ApplySuffix(aps.tok, aps.Lhs, argList);
}
}
}
}
} else if (expr is ExprDotName) {
var edn = (ExprDotName)expr;
var ns = edn.Lhs as NameSegment;
if (ns != null && state.ContainsVariable(ns)) {
var newLhs = state.GetLocalValue(ns);
var lhs = newLhs as Expression;
if (lhs != null)
yield return new ExprDotName(edn.tok, lhs, edn.SuffixName, edn.OptTypeArguments);
}
yield return edn;
} else if (expr is UnaryOpExpr) {
var op = (UnaryOpExpr)expr;
foreach (var result in EvaluateTacnyExpression(state, op.E)) {
switch (op.Op) {
case UnaryOpExpr.Opcode.Cardinality:
if (!(result is IEnumerable)) {
var resultExp = result is IVariable
? Util.VariableToExpression(result as IVariable)
: result as Expression;
yield return new UnaryOpExpr(op.tok, op.Op, resultExp);
} else {
var enumerator = result as IList;
if (enumerator != null)
yield return new Dafny.LiteralExpr(op.tok, enumerator.Count);
}
yield break;
case UnaryOpExpr.Opcode.Not:
if (result is Dafny.LiteralExpr) {
var lit = (Dafny.LiteralExpr)result;
if (lit.Value is bool) {
// inverse the bool value
yield return new Dafny.LiteralExpr(op.tok, !(bool)lit.Value);
} else {
Contract.Assert(false);
//TODO: error message
}
} else {
var resultExp = result is IVariable ? Util.VariableToExpression(result as IVariable) : result as Expression;
yield return new UnaryOpExpr(op.tok, op.Op, resultExp);
}
yield break;
default:
Contract.Assert(false, "Unsupported Unary Operator");
yield break;
}
}
} else if (expr is DisplayExpression) {
var dexpr = (DisplayExpression)expr;
if (dexpr.Elements.Count == 0) {
yield return dexpr.Copy();
} else {
foreach (var item in ResolveDisplayExpression(state, dexpr)) {
yield return item;
}
}
} else { yield return expr; }
}
public static IEnumerable <object> EvaluateTacnyExpression(ProofState state, Expression expr)
{
Contract.Requires <ArgumentNullException>(state != null, "state");
Contract.Requires <ArgumentNullException>(expr != null, "expr");
if (expr is NameSegment)
{
var ns = (NameSegment)expr;
if (state.HasLocalValue(ns.Name))
{
yield return(state.GetLocalValue(ns.Name));
}
else
{
yield return(ns);
}
}
else if (expr is ApplySuffix)
{
var aps = (ApplySuffix)expr;
if (state.IsTacticCall(aps))
{
var us = new UpdateStmt(aps.tok, aps.tok, new List <Expression>()
{
aps.Lhs
},
new List <AssignmentRhs>()
{
new ExprRhs(aps)
});
foreach (var item in ApplyNestedTactic(state, state.DafnyVars(), us).Select(x => x.GetGeneratedCode()))
{
yield return(item);
}
}
// rewrite the expression
if (aps.Lhs is ExprDotName)
{
foreach (var item in EvaluateTacnyExpression(state, aps.Lhs))
{
if (item is Expression)
{
yield return(new ApplySuffix(aps.tok, (Expression)item, aps.Args));
}
else
{
Contract.Assert(false, "Unexpected ExprNotName case");
}
}
}
else
{
// try to evaluate as tacny expression
string sig = Util.GetSignature(aps);
// using reflection find all classes that extend EAtomic
var types =
Assembly.GetAssembly(typeof(EAtomic.EAtomic)).GetTypes().Where(t => t.IsSubclassOf(typeof(EAtomic.EAtomic)));
foreach (var type in types)
{
var resolverInstance = Activator.CreateInstance(type) as EAtomic.EAtomic;
if (sig == resolverInstance?.Signature)
{
//TODO: validate input countx
foreach (var item in resolverInstance?.Generate(aps, state))
{
yield return(item);
}
}
// if we reached this point, rewrite the apply suffix
foreach (var item in EvaluateTacnyExpression(state, aps.Lhs))
{
if (!(item is NameSegment))
{
//TODO: warning
}
else
{
var argList = new List <Expression>();
foreach (var arg in aps.Args)
{
foreach (var result in EvaluateTacnyExpression(state, arg))
{
if (result is Expression)
{
argList.Add(result as Expression);
}
else
{
argList.Add(Util.VariableToExpression(result as IVariable));
}
break;
}
}
yield return(new ApplySuffix(aps.tok, aps.Lhs, argList));
}
}
}
}
}
else if (expr is ExprDotName)
{
var edn = (ExprDotName)expr;
var ns = edn.Lhs as NameSegment;
if (ns != null && state.ContainsVariable(ns))
{
var newLhs = state.GetLocalValue(ns);
var lhs = newLhs as Expression;
if (lhs != null)
{
yield return(new ExprDotName(edn.tok, lhs, edn.SuffixName, edn.OptTypeArguments));
}
}
yield return(edn);
}
else if (expr is UnaryOpExpr)
{
var op = (UnaryOpExpr)expr;
foreach (var result in EvaluateTacnyExpression(state, op.E))
{
switch (op.Op)
{
case UnaryOpExpr.Opcode.Cardinality:
if (!(result is IEnumerable))
{
var resultExp = result is IVariable
? Util.VariableToExpression(result as IVariable)
: result as Expression;
yield return(new UnaryOpExpr(op.tok, op.Op, resultExp));
}
else
{
var enumerator = result as IList;
if (enumerator != null)
{
yield return(new Dafny.LiteralExpr(op.tok, enumerator.Count));
}
}
yield break;
case UnaryOpExpr.Opcode.Not:
if (result is Dafny.LiteralExpr)
{
var lit = (Dafny.LiteralExpr)result;
if (lit.Value is bool)
{
// inverse the bool value
yield return(new Dafny.LiteralExpr(op.tok, !(bool)lit.Value));
}
else
{
Contract.Assert(false);
//TODO: error message
}
}
else
{
var resultExp = result is IVariable?Util.VariableToExpression(result as IVariable) : result as Expression;
yield return(new UnaryOpExpr(op.tok, op.Op, resultExp));
}
yield break;
default:
Contract.Assert(false, "Unsupported Unary Operator");
yield break;
}
}
}
else if (expr is DisplayExpression)
{
var dexpr = (DisplayExpression)expr;
if (dexpr.Elements.Count == 0)
{
yield return(dexpr.Copy());
}
else
{
foreach (var item in ResolveDisplayExpression(state, dexpr))
{
yield return(item);
}
}
}
else
{
yield return(expr);
}
}