MethodCallConverter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DLinq / Dlinq / SqlClient / Query / MethodCallConverter.cs / 1305376 / MethodCallConverter.cs
                        
                        
                            using System; 
using System.Collections.Generic;
using System.Text;
using System.Linq.Expressions;
using System.Reflection; 
using System.Data.Linq;
using System.Data.Linq.Provider; 
using System.Data.Linq.Mapping; 

namespace System.Data.Linq.SqlClient { 

    // convert special method calls and member accesses into known sql nodes

    internal static class PreBindDotNetConverter { 
        internal static SqlNode Convert(SqlNode node, SqlFactory sql, MetaModel model) {
            return new Visitor(sql, model).Visit(node); 
        } 

        internal static bool CanConvert(SqlNode node) { 
            SqlBinary bo = node as SqlBinary;
            if (bo != null && (IsCompareToValue(bo) || IsVbCompareStringEqualsValue(bo))) {
                return true;
            } 
            SqlMember sm = node as SqlMember;
            if (sm != null && IsSupportedMember(sm)) { 
                return true; 
            }
            SqlMethodCall mc = node as SqlMethodCall; 
            if (mc != null && (IsSupportedMethod(mc) || IsSupportedVbHelperMethod(mc))) {
                return true;
            }
            return false; 
        }
 
        private static bool IsCompareToValue(SqlBinary bo) { 
            if (IsComparison(bo.NodeType)
                && bo.Left.NodeType == SqlNodeType.MethodCall 
                && bo.Right.NodeType == SqlNodeType.Value) {
                SqlMethodCall call = (SqlMethodCall)bo.Left;
                return IsCompareToMethod(call) || IsCompareMethod(call);
            } 

            return false; 
        } 

        private static bool IsCompareToMethod(SqlMethodCall call) { 
            return !call.Method.IsStatic && call.Method.Name == "CompareTo" && call.Arguments.Count == 1 && call.Method.ReturnType == typeof(int);
        }

        private static bool IsCompareMethod(SqlMethodCall call) { 
            return call.Method.IsStatic && call.Method.Name == "Compare" && call.Arguments.Count > 1 && call.Method.ReturnType == typeof(int);
        } 
 
        private static bool IsComparison(SqlNodeType nodeType) {
            switch (nodeType) { 
                case SqlNodeType.EQ:
                case SqlNodeType.NE:
                case SqlNodeType.LT:
                case SqlNodeType.LE: 
                case SqlNodeType.GT:
                case SqlNodeType.GE: 
                case SqlNodeType.EQ2V: 
                case SqlNodeType.NE2V:
                    return true; 
                default:
                    return false;
            }
        } 

        private static bool IsVbCompareStringEqualsValue(SqlBinary bo) { 
            return IsComparison(bo.NodeType) 
                && bo.Left.NodeType == SqlNodeType.MethodCall
                && bo.Right.NodeType == SqlNodeType.Value 
                && IsVbCompareString((SqlMethodCall)bo.Left);
        }

        private static bool IsVbCompareString(SqlMethodCall call) { 
            return call.Method.IsStatic &&
                call.Method.DeclaringType.FullName == "Microsoft.VisualBasic.CompilerServices.Operators" && 
                call.Method.Name == "CompareString"; 
        }
 
        private static bool IsSupportedVbHelperMethod(SqlMethodCall mc) {
            return IsVbIIF(mc);
        }
 
        private static bool IsVbIIF(SqlMethodCall mc) {
            return mc.Method.IsStatic && 
                   mc.Method.DeclaringType.FullName == "Microsoft.VisualBasic.Interaction" && mc.Method.Name == "IIf"; 
        }
 
        private static bool IsSupportedMember(SqlMember m) {
            return IsNullableHasValue(m) || IsNullableHasValue(m);
        }
 
        private static bool IsNullableValue(SqlMember m) {
            return TypeSystem.IsNullableType(m.Expression.ClrType) && m.Member.Name == "Value"; 
        } 

        private static bool IsNullableHasValue(SqlMember m) { 
            return TypeSystem.IsNullableType(m.Expression.ClrType) && m.Member.Name == "HasValue";
        }

        private static bool IsSupportedMethod(SqlMethodCall mc) { 
            if (mc.Method.IsStatic) {
                switch (mc.Method.Name) { 
                    case "op_Equality": 
                    case "op_Inequality":
                    case "op_LessThan": 
                    case "op_LessThanOrEqual":
                    case "op_GreaterThan":
                    case "op_GreaterThanOrEqual":
                    case "op_Multiply": 
                    case "op_Division":
                    case "op_Subtraction": 
                    case "op_Addition": 
                    case "op_Modulus":
                    case "op_BitwiseAnd": 
                    case "op_BitwiseOr":
                    case "op_ExclusiveOr":
                    case "op_UnaryNegation":
                    case "op_OnesComplement": 
                    case "op_False":
                        return true; 
                    case "Equals": 
                        return mc.Arguments.Count == 2;
                    case "Concat": 
                        return mc.Method.DeclaringType == typeof(string);
                }
            }
            else { 
                return mc.Method.Name == "Equals" && mc.Arguments.Count == 1 ||
                       mc.Method.Name == "GetType" && mc.Arguments.Count == 0; 
            } 
            return false;
        } 

        private class Visitor : SqlVisitor {
            SqlFactory sql;
            MetaModel model; 

            internal Visitor(SqlFactory sql, MetaModel model) { 
                this.sql = sql; 
                this.model = model;
            } 

            internal override SqlExpression VisitBinaryOperator(SqlBinary bo) {
                if (IsCompareToValue(bo)) {
                    SqlMethodCall call = (SqlMethodCall)bo.Left; 
                    if (IsCompareToMethod(call)) {
                        int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture); 
                        bo = this.MakeCompareTo(call.Object, call.Arguments[0], bo.NodeType, iValue) ?? bo; 
                    }
                    else if (IsCompareMethod(call)) { 
                        int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture);
                        bo = this.MakeCompareTo(call.Arguments[0], call.Arguments[1], bo.NodeType, iValue) ?? bo;
                    }
                } 
                else if (IsVbCompareStringEqualsValue(bo)) {
                    SqlMethodCall call = (SqlMethodCall)bo.Left; 
                    int iValue = System.Convert.ToInt32(this.Eval(bo.Right), Globalization.CultureInfo.InvariantCulture); 
                    //in VB, comparing a string with Nothing means comparing with ""
                    SqlValue strValue = call.Arguments[1] as SqlValue; 
                    if (strValue != null && strValue.Value == null) {
                        SqlValue emptyStr = new SqlValue(strValue.ClrType, strValue.SqlType, String.Empty, strValue.IsClientSpecified, strValue.SourceExpression);
                        bo = this.MakeCompareTo(call.Arguments[0], emptyStr, bo.NodeType, iValue) ?? bo;
                    } 
                    else {
                        bo = this.MakeCompareTo(call.Arguments[0], call.Arguments[1], bo.NodeType, iValue) ?? bo; 
                    } 
                }
                return base.VisitBinaryOperator(bo); 
            }

            private SqlBinary MakeCompareTo(SqlExpression left, SqlExpression right, SqlNodeType op, int iValue) {
                if (iValue == 0) { 
                    return sql.Binary(op, left, right);
                } 
                else if (op == SqlNodeType.EQ || op == SqlNodeType.EQ2V) { 
                    switch (iValue) {
                        case -1: 
                            return sql.Binary(SqlNodeType.LT, left, right);
                        case 1:
                            return sql.Binary(SqlNodeType.GT, left, right);
                    } 
                }
                return null; 
            } 

            private SqlExpression CreateComparison(SqlExpression a, SqlExpression b, Expression source) { 
                SqlExpression lower = sql.Binary(SqlNodeType.LT, a, b);
                SqlExpression equal = sql.Binary(SqlNodeType.EQ2V, a, b);
                return sql.SearchedCase(
                    new SqlWhen[] { 
                        new SqlWhen(lower, sql.ValueFromObject(-1, false, source)),
                        new SqlWhen(equal, sql.ValueFromObject(0, false, source)), 
                        }, 
                    sql.ValueFromObject(1, false, source), source
                ); 
            }

            internal override SqlNode VisitMember(SqlMember m) {
                m.Expression = this.VisitExpression(m.Expression); 
                if (IsNullableValue(m)) {
                    return sql.UnaryValueOf(m.Expression, m.SourceExpression); 
                } 
                else if (IsNullableHasValue(m)) {
                    return sql.Unary(SqlNodeType.IsNotNull, m.Expression, m.SourceExpression); 
                }
                return m;
            }
 
            internal override SqlExpression VisitMethodCall(SqlMethodCall mc) {
                mc.Object = this.VisitExpression(mc.Object); 
                for (int i = 0, n = mc.Arguments.Count; i < n; i++) { 
                    mc.Arguments[i] = this.VisitExpression(mc.Arguments[i]);
                } 
                if (mc.Method.IsStatic) {
                    if (mc.Method.Name == "Equals" && mc.Arguments.Count == 2) {
                        return sql.Binary(SqlNodeType.EQ2V, mc.Arguments[0], mc.Arguments[1], mc.Method);
                    } 
                    else if (mc.Method.DeclaringType == typeof(string) && mc.Method.Name == "Concat") {
                        SqlClientArray arr = mc.Arguments[0] as SqlClientArray; 
                        List exprs = null; 
                        if (arr != null) {
                            exprs = arr.Expressions; 
                        }
                        else {
                            exprs = mc.Arguments;
                        } 
                        if (exprs.Count == 0) {
                            return sql.ValueFromObject("", false, mc.SourceExpression); 
                        } 
                        else {
                            SqlExpression sum; 
                            if (exprs[0].SqlType.IsString || exprs[0].SqlType.IsChar) {
                                sum = exprs[0];
                            }
                            else { 
                                sum = sql.ConvertTo(typeof(string), exprs[0]);
                            } 
                            for (int i = 1; i < exprs.Count; i++) { 
                                if (exprs[i].SqlType.IsString || exprs[i].SqlType.IsChar) {
                                    sum = sql.Concat(sum, exprs[i]); 
                                }
                                else {
                                    sum = sql.Concat(sum, sql.ConvertTo(typeof(string), exprs[i]));
                                } 
                            }
                            return sum; 
                        } 
                    }
                    else if (IsVbIIF(mc)) { 
                        return TranslateVbIIF(mc);
                    }
                    else {
                        switch (mc.Method.Name) { 
                            case "op_Equality":
                                return sql.Binary(SqlNodeType.EQ, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType); 
                            case "op_Inequality": 
                                return sql.Binary(SqlNodeType.NE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_LessThan": 
                                return sql.Binary(SqlNodeType.LT, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_LessThanOrEqual":
                                return sql.Binary(SqlNodeType.LE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_GreaterThan": 
                                return sql.Binary(SqlNodeType.GT, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_GreaterThanOrEqual": 
                                return sql.Binary(SqlNodeType.GE, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType); 
                            case "op_Multiply":
                                return sql.Binary(SqlNodeType.Mul, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType); 
                            case "op_Division":
                                return sql.Binary(SqlNodeType.Div, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_Subtraction":
                                return sql.Binary(SqlNodeType.Sub, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType); 
                            case "op_Addition":
                                return sql.Binary(SqlNodeType.Add, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType); 
                            case "op_Modulus": 
                                return sql.Binary(SqlNodeType.Mod, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_BitwiseAnd": 
                                return sql.Binary(SqlNodeType.BitAnd, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_BitwiseOr":
                                return sql.Binary(SqlNodeType.BitOr, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_ExclusiveOr": 
                                return sql.Binary(SqlNodeType.BitXor, mc.Arguments[0], mc.Arguments[1], mc.Method, mc.ClrType);
                            case "op_UnaryNegation": 
                                return sql.Unary(SqlNodeType.Negate, mc.Arguments[0], mc.Method, mc.SourceExpression); 
                            case "op_OnesComplement":
                                return sql.Unary(SqlNodeType.BitNot, mc.Arguments[0], mc.Method, mc.SourceExpression); 
                            case "op_False":
                                return sql.Unary(SqlNodeType.Not, mc.Arguments[0], mc.Method, mc.SourceExpression);
                        }
                    } 
                }
                else { 
                    if (mc.Method.Name == "Equals" && mc.Arguments.Count == 1) { 
                        return sql.Binary(SqlNodeType.EQ, mc.Object, mc.Arguments[0]);
                    } 
                    else if (mc.Method.Name == "GetType" && mc.Arguments.Count == 0) {
                        MetaType mt = TypeSource.GetSourceMetaType(mc.Object, this.model);
                        if (mt.HasInheritance) {
                            Type discriminatorType = mt.Discriminator.Type; 
                            SqlDiscriminatorOf discriminatorOf = new SqlDiscriminatorOf(mc.Object, discriminatorType, this.sql.TypeProvider.From(discriminatorType), mc.SourceExpression);
                            return this.VisitExpression(sql.DiscriminatedType(discriminatorOf, mt)); 
                        } 
                        return this.VisitExpression(sql.StaticType(mt, mc.SourceExpression));
                    } 
                }
                return mc;
            }
 
            private SqlExpression TranslateVbIIF(SqlMethodCall mc) {
                //Check to see if the types can be implicitly converted from one to another. 
                if (mc.Arguments[1].ClrType == mc.Arguments[2].ClrType) { 
                    List whens = new List(1);
                    whens.Add(new SqlWhen(mc.Arguments[0], mc.Arguments[1])); 
                    SqlExpression @else = mc.Arguments[2];
                    while (@else.NodeType == SqlNodeType.SearchedCase) {
                        SqlSearchedCase sc = (SqlSearchedCase)@else;
                        whens.AddRange(sc.Whens); 
                        @else = sc.Else;
                    } 
                    return sql.SearchedCase(whens.ToArray(), @else, mc.SourceExpression); 
                }
                else { 
                    throw Error.IifReturnTypesMustBeEqual(mc.Arguments[1].ClrType.Name, mc.Arguments[2].ClrType.Name);
                }
            }
 
            internal override SqlExpression VisitTreat(SqlUnary t) {
                t.Operand = this.VisitExpression(t.Operand); 
                Type treatType = t.ClrType; 
                Type originalType = model.GetMetaType(t.Operand.ClrType).InheritanceRoot.Type;
 
                // .NET nullability rules are that typeof(int)==typeof(int?). Let's be consistent with that:
                treatType = TypeSystem.GetNonNullableType(treatType);
                originalType = TypeSystem.GetNonNullableType(originalType);
 
                if (treatType == originalType) {
                    return t.Operand; 
                } 
                else if (treatType.IsAssignableFrom(originalType)) {
                    t.Operand.SetClrType(treatType); 
                    return t.Operand;
                }
                else if (!treatType.IsAssignableFrom(originalType) && !originalType.IsAssignableFrom(treatType)) {
                    if (!treatType.IsInterface && !originalType.IsInterface) { // You can't tell when there's an interface involved. 
                        // We statically know the TREAT will result in NULL.
                        return sql.TypedLiteralNull(treatType, t.SourceExpression); 
                    } 
                }
                //return base.VisitTreat(t); 
                return t;
            }
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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MethodCallConverter.cs source code in C# .NET

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