// evaluate starts evaluation with fresh environment
public static ExpressionValue Evaluate(Expression exp, Valuation env)
{
switch (exp.ExpressionType)
{
case ExpressionType.Constant:
return(exp as ExpressionValue);
case ExpressionType.Variable:
// Look up variable in environment; we assume
// that value is found
try
{
return(env.Variables[exp.expressionID]);
}
catch (KeyNotFoundException)
{
throw new EvaluatingException("Access the non existing variable: " + exp.expressionID);
}
catch (Exception ex)
{
throw new EvaluatingException("Variable evaluation exception for variable '" + exp.expressionID + "':" + ex.Message);
}
case ExpressionType.Record:
{
Expression[] ass = ((Record)exp).Associations;
ExpressionValue[] values = new ExpressionValue[ass.Length];
for (int i = 0; i < ass.Length; i++)
{
//rv.Put(association.Property, store.Extend(Eval(association.Expression, env)));
//rv.Put(Eval(association, env));
values[i] = Evaluate(ass[i], env);
#if !OPTIMAL_FOR_EXP
if (values[i] == null)
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
#endif
}
RecordValue rv = new RecordValue(values);
return(rv);
}
case ExpressionType.PrimitiveApplication:
// First evaluate the first argument, then the second, and
// then evaluate using evalPrimAppl.
{
PrimitiveApplication newexp = exp as PrimitiveApplication;
ExpressionValue x1 = Evaluate(newexp.Argument1, env);
Debug.Assert(x1 != null);
#if !OPTIMAL_FOR_EXP
if (x1 == null)
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
#endif
return(EvalPrimAppl(newexp, x1, newexp.Argument2, env));
}
case ExpressionType.Assignment:
{
//Assign the rhs to lhs
String lhs = ((Assignment)exp).LeftHandSide;
Expression rhs = ((Assignment)exp).RightHandSide;
ExpressionValue rhsV = Evaluate(rhs, env);
#if !OPTIMAL_FOR_EXP
if (rhsV == null)
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
Valuation.CheckVariableRange(lhs, rhsV);
#endif
env.Variables[lhs] = rhsV;
return(rhsV);
}
case ExpressionType.PropertyAssignment:
{
try
{
PropertyAssignment pa = (PropertyAssignment)exp;
RecordValue rec = (RecordValue)Evaluate(pa.RecordExpression, env);
IntConstant pro = (IntConstant)Evaluate(pa.PropertyExpression, env);
ExpressionValue rhs = Evaluate(pa.RightHandExpression, env);
//rec.Put(pro.PropertyName, store.Extend(rhs));
int index = pro.Value;
if (index < 0)
{
throw new NegativeArraySizeException("Access negative index " + index + " for variable " + pa.RecordExpression.ToString());
}
else if (index >= rec.Associations.Length)
{
throw new IndexOutOfBoundsException("Index " + index + " is out of range for variable " + pa.RecordExpression.ToString());
}
#if !OPTIMAL_FOR_EXP
if (rhs == null)
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
Valuation.CheckVariableRange(pa.RecordExpression.ToString(), rhs);
#endif
rec.Associations[index] = rhs;
//Note:Important!!! must recalculate the ID here, otherwise ID is obsolete and the verification result is wrong
rec.GetID();
return(rhs);
}
catch (InvalidCastException ex)
{
throw new RuntimeException("Invalid Cast Exception for " + exp + ": " + ex.Message.Replace("PAT.Common.Classes.Expressions.ExpressionClass.", ""));
}
}
case ExpressionType.If:
// Conditionals are evaluated by evaluating the then-part or
// else-part depending of the result of evaluating the condition.
{
ExpressionValue cond = Evaluate(((If)exp).Condition, env);
if (((BoolConstant)cond).Value)
{
return(Evaluate(((If)exp).ThenPart, env));
}
else if (((If)exp).ElsePart != null)
{
return(Evaluate(((If)exp).ElsePart, env));
}
else
{
return(null);
}
}
case ExpressionType.Sequence:
// firstPart;secondPart
Expression fP = ((Sequence)exp).FirstPart;
Expression sP = ((Sequence)exp).SecondPart;
Evaluate(fP, env);
return(Evaluate(sP, env));
case ExpressionType.While:
Expression test = ((While)exp).Test;
Expression body = ((While)exp).Body;
// the value of test may not be a Value.
// here we assume it is always a Value, which
// may cause run time exception due to non-Value.
if (((BoolConstant)Evaluate(test, env)).Value)
{
// test is ture
Evaluate(body, env); // body serves to change the store
return(Evaluate(exp, env)); // evaluate the While again
}
else
{
return(null);
}
case ExpressionType.StaticMethodCall:
try
{
StaticMethodCall methodCall = (StaticMethodCall)exp;
if (methodCall.Arguments.Length > 0)
{
ChannelQueue queue;
string cname = null;
if ((methodCall.Arguments[0] is Variable))
{
cname = (methodCall.Arguments[0] as Variable).ExpressionID;
}
else if (methodCall.Arguments[0] is PrimitiveApplication)
{
PrimitiveApplication pa = (methodCall.Arguments[0] as PrimitiveApplication);
ExpressionValue ind = Evaluate(pa.Argument2, env);
cname = pa.Argument1 + "[" + ind + "]";
}
switch (methodCall.MethodName)
{
case Common.Classes.Ultility.Constants.cfull:
if (env.Channels.TryGetValue(cname, out queue))
{
return(new BoolConstant(queue.IsFull()));
}
else
{
throw new RuntimeException("Channel " + cname +
" is not used in the model. Therefore it is meaningless to query channel information using " +
methodCall + ".");
}
case Common.Classes.Ultility.Constants.cempty:
if (env.Channels.TryGetValue(cname, out queue))
{
return(new BoolConstant(queue.IsEmpty()));
}
else
{
throw new RuntimeException("Channel " + cname +
" is not used in the model. Therefore it is meaningless to query channel information using " +
methodCall + ".");
}
case Common.Classes.Ultility.Constants.ccount:
if (env.Channels.TryGetValue(cname, out queue))
{
return(new IntConstant(queue.Count));
}
else
{
throw new RuntimeException("Channel " + cname +
" is not used in the model. Therefore it is meaningless to query channel information using " +
methodCall + ".");
}
case Common.Classes.Ultility.Constants.csize:
if (env.Channels.TryGetValue(cname, out queue))
{
return(new IntConstant(queue.Size));
}
else
{
throw new RuntimeException("Channel " + cname +
" is not used in the model. Therefore it is meaningless to query channel information using " +
methodCall + ".");
}
case Common.Classes.Ultility.Constants.cpeek:
if (env.Channels.TryGetValue(cname, out queue))
{
if (queue.Count == 0)
{
throw new IndexOutOfBoundsException("Channel " + cname +
"'s buffer is empty!");
}
return(new RecordValue(queue.Peek()));
}
else
{
throw new RuntimeException("Channel " + cname +
" is not used in the model. Therefore it is meaningless to query channel information using " +
methodCall + ".");
}
}
}
object[] paras = new object[methodCall.Arguments.Length];
for (int i = 0; i < paras.Length; i++)
{
ExpressionValue x1 = Evaluate(methodCall.Arguments[i], env);
paras[i] = GetValueFromExpression(x1);
}
string key = methodCall.MethodName + paras.Length;
if (Common.Utility.Utilities.CSharpMethods.ContainsKey(key))
{
object resultv = Common.Utility.Utilities.CSharpMethods[key].Invoke(null, paras);
if (Common.Utility.Utilities.CSharpMethods[key].ReturnType.Name == "Void")
{
return(null);
}
if (resultv is bool)
{
return(new BoolConstant((bool)resultv));
}
else if (resultv is int || resultv is short || resultv is byte || resultv is double)
{
return(new IntConstant(Convert.ToInt32(resultv)));
}
else if (resultv is int[])
{
int[] list = resultv as int[];
ExpressionValue[] vals = new ExpressionValue[list.Length];
for (int i = 0; i < vals.Length; i++)
{
vals[i] = new IntConstant(list[i]);
}
return(new RecordValue(vals));
}
else if (resultv is ExpressionValue)
{
return(resultv as ExpressionValue);
}
return(new NullConstant());
//the following check is not necessary, since we will only keep bool, int and int[] methods
//else
//{
// throw new Expressions.ExpressionClass.RuntimeException("Call expression can only return int, short, byte, bool or int[] types. Please check your methods.");
//}
}
throw new RuntimeException("Invalid Method Call: " + methodCall + "! Make sure you have defined the method in the library.");
}
catch (TargetInvocationException ex)
{
if (ex.InnerException != null)
{
RuntimeException exception =
new RuntimeException("Exception happened at expression " + exp + ": " +
ex.InnerException.Message);
exception.InnerStackTrace = ex.InnerException.StackTrace;
throw exception;
}
else
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
}
catch (Exception ex)
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
case ExpressionType.ClassMethodCall:
try
{
ClassMethodCall methodCall = (ClassMethodCall)exp;
ExpressionValue variable = env.Variables[methodCall.Variable];
if (variable == null)
{
throw new RuntimeException("Exception happened at expression " + exp + ": variable " + methodCall.Variable + "'s value is null");
}
object[] paras = new object[methodCall.Arguments.Length];
for (int i = 0; i < paras.Length; i++)
{
ExpressionValue x1 = Evaluate(methodCall.Arguments[i], env);
paras[i] = GetValueFromExpression(x1);
}
MethodInfo methodInfo = variable.GetType().GetMethod(methodCall.MethodName);
if (methodInfo != null)
{
object resultv = methodInfo.Invoke(variable, BindingFlags.InvokeMethod, null, paras, CultureInfo.InvariantCulture);
if (methodInfo.ReturnType.Name == "Void")
{
return(null);
}
if (resultv is bool)
{
return(new BoolConstant((bool)resultv));
}
else if (resultv is int || resultv is short || resultv is byte || resultv is double)
{
return(new IntConstant(Convert.ToInt32(resultv)));
}
else if (resultv is int[])
{
int[] list = resultv as int[];
ExpressionValue[] vals = new ExpressionValue[list.Length];
for (int i = 0; i < vals.Length; i++)
{
vals[i] = new IntConstant(list[i]);
}
return(new RecordValue(vals));
}
else if (resultv is ExpressionValue)
{
return(resultv as ExpressionValue);
}
else if (resultv == null)
{
return(new NullConstant());
}
//return null;
//the following check is not necessary, since we will only keep bool, int and int[] methods
throw new RuntimeException("Call expression can only return int, short, byte, bool or int[] types. Please check your statement: " + methodCall.ToString() + ".");
}
throw new RuntimeException("Invalid Method Call: " + methodCall + "! Make sure you have defined the method in the library.");
}
catch (TargetInvocationException ex)
{
if (ex.InnerException != null)
{
RuntimeException exception =
new RuntimeException("Exception happened at expression " + exp + ": " +
ex.InnerException.Message);
exception.InnerStackTrace = ex.InnerException.StackTrace;
throw exception;
}
else
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
}
catch (Exception ex)
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
case ExpressionType.ClassMethodCallInstance:
try
{
ClassMethodCallInstance methodCall = (ClassMethodCallInstance)exp;
ExpressionValue variable = Evaluate(methodCall.Variable, env);
object[] paras = new object[methodCall.Arguments.Length];
for (int i = 0; i < paras.Length; i++)
{
ExpressionValue x1 = Evaluate(methodCall.Arguments[i], env);
paras[i] = GetValueFromExpression(x1);
}
MethodInfo methodInfo = variable.GetType().GetMethod(methodCall.MethodName);
if (methodInfo != null)
{
object resultv = methodInfo.Invoke(variable, paras);
if (methodInfo.ReturnType.Name == "Void")
{
return(null);
}
if (resultv is bool)
{
return(new BoolConstant((bool)resultv));
}
else if (resultv is int || resultv is short || resultv is byte || resultv is double)
{
return(new IntConstant(Convert.ToInt32(resultv)));
}
else if (resultv is int[])
{
int[] list = resultv as int[];
ExpressionValue[] vals = new ExpressionValue[list.Length];
for (int i = 0; i < vals.Length; i++)
{
vals[i] = new IntConstant(list[i]);
}
return(new RecordValue(vals));
}
else if (resultv is ExpressionValue)
{
return(resultv as ExpressionValue);
}
else if (resultv == null)
{
return(new NullConstant());
}
//return null;
//the following check is not necessary, since we will only keep bool, int and int[] methods
throw new RuntimeException("Call expression can only return int, short, byte, bool or int[] types. Please check your statement: " + methodCall.ToString() + ".");
}
throw new RuntimeException("Invalid Method Call: " + methodCall + "! Make sure you have defined the method in the library.");
}
catch (TargetInvocationException ex)
{
if (ex.InnerException != null)
{
RuntimeException exception =
new RuntimeException("Exception happened at expression " + exp + ": " +
ex.InnerException.Message);
exception.InnerStackTrace = ex.InnerException.StackTrace;
throw exception;
}
else
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
}
catch (Exception ex)
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
case ExpressionType.ClassProperty:
try
{
ClassProperty property = (ClassProperty)exp;
ExpressionValue variable = Evaluate(property.Variable, env);
PropertyInfo propertyInfo = variable.GetType().GetProperty(property.PropertyName);
object resultv = null;
if (propertyInfo != null)
{
resultv = propertyInfo.GetValue(variable, null);
}
else
{
FieldInfo fieldInfo = variable.GetType().GetField(property.PropertyName);
if (fieldInfo != null)
{
resultv = fieldInfo.GetValue(variable);
}
}
if (resultv != null)
{
if (resultv is bool)
{
return(new BoolConstant((bool)resultv));
}
else if (resultv is int || resultv is short || resultv is byte || resultv is double)
{
return(new IntConstant(Convert.ToInt32(resultv)));
}
else if (resultv is int[])
{
int[] list = resultv as int[];
ExpressionValue[] vals = new ExpressionValue[list.Length];
for (int i = 0; i < vals.Length; i++)
{
vals[i] = new IntConstant(list[i]);
}
return(new RecordValue(vals));
}
else if (resultv is ExpressionValue)
{
return(resultv as ExpressionValue);
}
//else if (resultv == null)
//{
// return new NullConstant();
//}
//return null;
//the following check is not necessary, since we will only keep bool, int and int[] methods
throw new RuntimeException("Call expression can only return int, short, byte, bool or int[] types. Please check your statement: " + property.ToString() + ".");
}
throw new RuntimeException("Invalid Property Accessing: " + property + "! Make sure you have defined the method in the library.");
}
catch (TargetInvocationException ex)
{
if (ex.InnerException != null)
{
RuntimeException exception =
new RuntimeException("Exception happened at expression " + exp + ": " +
ex.InnerException.Message);
exception.InnerStackTrace = ex.InnerException.StackTrace;
throw exception;
}
else
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
}
catch (Exception ex)
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
case ExpressionType.ClassPropertyAssignment:
{
try
{
ClassPropertyAssignment pa = (ClassPropertyAssignment)exp;
ExpressionValue rhs = Evaluate(pa.RightHandExpression, env);
#if !OPTIMAL_FOR_EXP
if (rhs == null)
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
#endif
ClassProperty property = pa.ClassProperty;
ExpressionValue variable = Evaluate(property.Variable, env);
PropertyInfo propertyInfo = variable.GetType().GetProperty(property.PropertyName);
if (propertyInfo != null)
{
propertyInfo.SetValue(variable, GetValueFromExpression(rhs), null);
}
else
{
FieldInfo fieldInfo = variable.GetType().GetField(property.PropertyName);
if (fieldInfo != null)
{
fieldInfo.SetValue(variable, GetValueFromExpression(rhs));
}
else
{
throw new RuntimeException("Invalid expression assignment: " + exp);
}
}
return(rhs);
}
catch (InvalidCastException ex)
{
throw new RuntimeException("Invalid Cast Exception for " + exp + ": " + ex.Message.Replace("PAT.Common.Classes.Expressions.ExpressionClass.", ""));
}
}
case ExpressionType.Let:
LetDefinition definition = exp as LetDefinition;
ExpressionValue rhv = Evaluate(definition.RightHandExpression, env);
env.ExtendDestructive(definition.Variable, rhv);
return(null);
case ExpressionType.NewObjectCreation:
try
{
NewObjectCreation methodCall = (NewObjectCreation)exp;
object[] paras = new object[methodCall.Arguments.Length];
for (int i = 0; i < paras.Length; i++)
{
ExpressionValue x1 = Evaluate(methodCall.Arguments[i], env);
paras[i] = GetValueFromExpression(x1);
}
Type classType;
if (Common.Utility.Utilities.CSharpDataType.TryGetValue(methodCall.ClassName, out classType))
{
object resultv = Activator.CreateInstance(classType, paras);
if (resultv is ExpressionValue)
{
return(resultv as ExpressionValue);
}
//return null;
//the following check is not necessary, since we will only keep bool, int and int[] methods
throw new RuntimeException("Only object of class inheriting from ExpressionValue can be created. Please check your statement: " + methodCall.ToString() + ".");
}
throw new RuntimeException("Invalid Object Creation: " + methodCall + "! Make sure you have defined the class in the library.");
}
catch (Exception ex)
{
throw new RuntimeException("Exception happened at expression " + exp + ": " + ex.Message);
}
//case ExpressionType.UserDefinedDataType:
// return exp as ;
/* case ExpressionType.Let:
* // Evaluate body with respect to environment extended by binding of leftHand to rightHand
* {
* Valuation newenv = env.GetVariableClone();
* foreach (LetDefinition def in ((Let) exp).Definitions)
* {
* Value rhv = Evaluate(def.RightHandExpression, env);
* //newenv = Extend(newenv, def.Variable, rhv);
* //newenv = newenv.Extend(def.Variable, rhv);
* newenv.ExtendDestructive(def.Variable, rhv);
* }
* return Evaluate(((Let) exp).Body, newenv);
* }
* case ExpressionType.Fun:
* return new FunValue(env, ((Fun) exp).Formals, ((Fun) exp).Body);
* case ExpressionType.RecFun:
* // For recursive functions, we need to place an environment
* // in the function that has a binding of the function variable
* // to the function itself. For this, we obtain a clone of the
* // environment, making sure that a destructive change will
* // not have any effect on the original environment. Then, we
* // place the clone in the function value. After that, we
* // destructively change the environment by a binding of the
* // function variable to the constructed function value.
* {
* Valuation newEnv = env.GetVariableClone(); // (Valuation)env.Clone();
* Value result = new FunValue(newEnv, ((RecFun) exp).Formals, ((RecFun) exp).body);
* //ExtendDestructive(newEnv, ((RecFun)exp).FunVar, result);
* newEnv.ExtendDestructive(((RecFun) exp).FunVar, result);
* return result;
* }
* case ExpressionType.Application:
* // Apply the function value resulting from evaluating the operator
* // (we assume that this is a function value) to
* // the value resulting from evaluating the operand.
* // Note that we do not need to distinguish functions from
* // recursive functions. Both are represented by function values,
* // recursive functions have a binding of their function variable
* // to themselves in their environment.
* {
* FunValue fun = (FunValue) Evaluate(((Application) exp).Operator, env);
* Valuation newenv = (Valuation) fun.Valuation;
*
* List<Expression> ops = ((Application) exp).Operands;
* List<string> fe = fun.Formals;
*
* for (int i = 0; i < ops.Count; i++)
* {
* Value argvalue = Evaluate(ops[i], env);
* //newenv = Extend(newenv, fe[i], argvalue);
* newenv = newenv.Extend((String) fe[i], argvalue);
* }
* return Evaluate(fun.Body, newenv);
* }*/
}
// (exp instanceof NotUsed)
// NotUsed is used as argument2 of PrimitiveApplication.
// We assume the resulting value will not be used,
// thus any value will do, here.
return(new BoolConstant(true));
}
