コード例 #1
0
        private Expression ParseUnaryExpression(string s)
        {
            var relevantParser = UnaryExpressionParser.For(s);

            if (relevantParser == null)
            {
                throw new Exception($"Unrecognized expression {s}.");
            }

            var expression          = relevantParser.Parse(s);
            var parameterExpression = expression as ParameterExpression;

            if (parameterExpression != null)
            {
                Parameters.Add(parameterExpression);
            }
            else if (expression.NodeType == ExpressionType.Not)
            {
                Parameters.Add(((UnaryExpression)expression).Operand as ParameterExpression);
            }
            else if (expression.NodeType == ExpressionType.Call)
            {
                var methodCallExpression = expression as MethodCallExpression;
                foreach (var param in methodCallExpression.Arguments)
                {
                    var paramExpression = ((UnaryExpression)param).Operand as ParameterExpression ?? param as ParameterExpression;
                    Parameters.Add(paramExpression);
                }
            }

            return(expression);
        }
コード例 #2
0
        public Expression Parse(string s)
        {
            s = s.Trim();
            var fullName = s.Substring(0, s.IndexOf("("));
            var dotIndex = fullName.LastIndexOf(".");

            if (dotIndex == -1)
            {
                throw new Exception($"You have to specify static type for function {fullName}, for example Math.Sin(30).");
            }
            var typeName   = fullName.Substring(0, dotIndex);
            var staticType = Type.GetType(typeName);

            if (staticType == null)
            {
                throw new Exception($"Could not find type {typeName}.");
            }
            var methodName = fullName.Substring(dotIndex + 1, fullName.Length - dotIndex - 1);
            var method     = staticType.GetTypeInfo().GetDeclaredMethod(methodName);

            if (method == null)
            {
                throw new Exception($"Could not find metehod {methodName} in type {typeName}.");
            }
            var unparsedParameters = s.Replace(fullName, "").Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(up => up.Trim()).ToArray();
            var methodParameters   = method.GetParameters();
            var paramIndex         = 0;
            var parameters         = unparsedParameters.Select(up =>
            {
                var parser = UnaryExpressionParser.For(up);
                if (up == null)
                {
                    throw new Exception($"Unrecognized expression {up} in parameters of function {fullName}.");
                }
                var parameterExpression = parser.Parse(up);
                return(Expression.Convert(parameterExpression, methodParameters[paramIndex++].ParameterType));
            }
                                                               ).ToArray();

            return(Expression.Call(method, parameters));
        }