/// <summary>
/// Creates constant expression. Main problem is to pick up right type if no recommended provided.
/// </summary>
private static Expression CreateConstantExpression(MemberOrConstantToken mcToken, Type recommendedType)
{
object obj;
if (recommendedType != null)
{
TypeUtils.ConvertFromString(mcToken.StrValue, recommendedType, out obj);
}
else
{
do
{
if (TypeUtils.ConvertFromString(mcToken.StrValue, typeof(int), out obj))
{
break;
}
if (TypeUtils.ConvertFromString(mcToken.StrValue, typeof(float), out obj))
{
break;
}
if (TypeUtils.ConvertFromString(mcToken.StrValue, typeof(bool), out obj))
{
break;
}
if (TypeUtils.ConvertFromString(mcToken.StrValue, typeof(DateTime), out obj))
{
break;
}
if (TypeUtils.ConvertFromString(mcToken.StrValue, typeof(string), out obj))
{
break;
}
}while (false);
}
Expression result = recommendedType == null?Expression.Constant(obj) : Expression.Constant(obj, recommendedType);
return(result);
}
/// <summary>
/// Builds expressions related to Property extraction, Function call, Type conversion and Constants
/// </summary>
/// <param name="tokens">Tokens list</param>
/// <param name="contexts">List of ParameterExpressions - variables which will be passed as Funtor's arguments</param>
/// <param name="recommendedType">If not null, tryes to convert resulted type of expression to recommendedType (no 100% guarantee)</param>
/// <returns>Expression</returns>
private static Expression BuildMembersExpression(ListSegment <Token> tokens, List <Expression> contexts, Type recommendedType)
{
int state = 0; //0-separator, 1-expression, 2-function
Expression result = contexts[0];
MemberOrConstantToken methodToken = null;
MemberOrConstantToken conversionToken = null;
for (int i = 0; i < tokens.Count; ++i)
{
switch (state)
{
case 0:
{
MemberOrConstantToken mcToken = tokens[i] as MemberOrConstantToken;
if (mcToken != null)
{
if (mcToken.IsString)
{
if (i == 0)
{
result = Expression.Constant(mcToken.StrValue);
}
else
{
throw new BuilderException(mcToken.Position, BuilderException.BuilderExceptionType.UnexpectedConstant, mcToken.StrValue);
}
}
else if (i == tokens.Count - 1 || tokens[i + 1] is PointToken)
{
if (i == 0 && mcToken.StrValue.Length > 2 && mcToken.StrValue.Substring(0, 3).ToLower() == "arg")
{
string numstr = mcToken.StrValue.Substring(3);
if (numstr != string.Empty)
{
int num = 0;
try { num = Convert.ToInt32(numstr); }
catch { throw new BuilderException(mcToken.Position, BuilderException.BuilderExceptionType.WrongArgFormat); }
if (num >= contexts.Count)
{
throw new BuilderException(mcToken.Position, BuilderException.BuilderExceptionType.ArgNumberExceedsMax);
}
result = contexts[num];
}
}
else
{
PropertyInfo pi = TypeUtils.GetPropertyInfo(result.Type, mcToken.StrValue);
if (pi != null)
{
result = Expression.Property(result, pi);
}
else if (i == 0)
{
result = CreateConstantExpression(mcToken, tokens.Count == 1 ? recommendedType : null);
}
else
{
throw new BuilderException(mcToken.Position, BuilderException.BuilderExceptionType.PropertyNotExists, pi.Name);
}
}
}
else
{
if (i == 0 && mcToken.IsConversion)
{
conversionToken = mcToken;
state = 2;
}
else
{
if (TypeUtils.MethodExists(result.Type, mcToken.StrValue))
{
state = 2; methodToken = mcToken;
}
else if (i == 0)
{
result = CreateConstantExpression(mcToken, tokens.Count == 1 ? recommendedType : null);
}
else
{
throw new BuilderException(mcToken.Position, BuilderException.BuilderExceptionType.FunctionNotExists, mcToken.StrValue);
}
}
}
if (state == 0)
{
state = 1;
}
break;
}
BracketsToken brToken = tokens[i] as BracketsToken;
if (brToken != null)
{
result = BuildExpression(new ListSegment <Token>(brToken.Tokens), contexts, null);
state = 1;
break;
}
throw new BuilderException(tokens[i].Position, BuilderException.BuilderExceptionType.IncorrectExpression);
}
case 1:
if (tokens[i] is PointToken)
{
state = 0;
}
else
{
throw new BuilderException(tokens[i].Position, BuilderException.BuilderExceptionType.UnexpectedExpression);
}
break;
case 2:
{
BracketsToken brToken = tokens[i] as BracketsToken;
if (brToken != null)
{
int argsCount = GetParamsNumber(brToken);
if (methodToken != null)
{
MethodInfo mi = TypeUtils.GetMethodInfo(result.Type, methodToken.StrValue, 0);
if (mi == null)
{
throw new BuilderException(methodToken.Position, BuilderException.BuilderExceptionType.NoFunctionFound);
}
if (argsCount == 0)
{
result = Expression.Call(result, mi);
}
else
{
ParameterInfo[] pinfos = mi.GetParameters();
List <Type> recommendedTypes = new List <Type>();
for (int j = 0; j < pinfos.Length; ++j)
{
if (!pinfos[j].IsOut && !pinfos[j].IsRetval)
{
recommendedTypes.Add(pinfos[j].ParameterType);
}
else
{
throw new BuilderException(tokens[i].Position, BuilderException.BuilderExceptionType.ParameterTypeNotSupported, pinfos[j].Name);
}
}
List <Expression> args = BuildFunctionArgumentsList(brToken, contexts, recommendedTypes);
result = Expression.Call(result, mi, args);
}
}
else if (conversionToken != null)
{
if (argsCount != 1)
{
throw new BuilderException(conversionToken.Position, BuilderException.BuilderExceptionType.WrongArgumentsNumber, "1 expected");
}
List <Type> recommendedTypes = new List <Type>();
recommendedTypes.Add(null);
List <Expression> args = BuildFunctionArgumentsList(brToken, contexts, recommendedTypes);
result = conversionToken.CreateConversion(args[0]);
}
else
{
throw new BuilderException(brToken.Position, BuilderException.BuilderExceptionType.UnexpectedError);
}
methodToken = null;
conversionToken = null;
state = 1;
}
else
{
throw new BuilderException(tokens[i].Position, BuilderException.BuilderExceptionType.FunctionArgumentsExpected);
}
}
break;
}
}
if (state == 2)
{
throw new BuilderException(tokens[tokens.Count - 1].Position, BuilderException.BuilderExceptionType.FunctionArgumentsExpected);
}
return(result);
}
