/// <summary>
/// Builds <see cref="Expression"/> that properly wraps given expression to return valid PHP type.
/// It does not perform any conversion for PHP primitive types. Byte array is wrapped into <see cref="PhpBytes"/> and
/// anything else is wrapped using <see cref="ClrObject.Create"/> method.
/// </summary>
/// <param name="expression">Expression returning an object/value.</param>
/// <returns><see cref="Expression"/> returning valid PHP object.</returns>
public static Expression /*!*/ ClrObjectWrapDynamic(Expression /*!*/ expression)
{
Debug.Assert(expression != null);
var type = expression.Type;
if (type.IsGenericParameter)
{
type = Types.Object[0];
}
// PHP types as they are:
if (PhpVariable.IsPrimitiveType(type) || /*Types.DObject[0].IsAssignableFrom(type) || */ typeof(IPhpVariable).IsAssignableFrom(type))
{
return(expression);
}
// (byte[])<expression> -> PhpBytes( <expression> )
// (byte[])null -> null
if (type == typeof(byte[]))
{
var value = Expression.Variable(typeof(byte[]));
return
(Expression.Block(Types.PhpBytes[0],
new[] { value },
Expression.Condition(
Expression.Equal(Expression.Assign(value, expression), Expression.Constant(null)),
Expression.Constant(null, Types.PhpBytes[0]),
Expression.New(Constructors.PhpBytes_ByteArray, value)
)));
}
// from Emit/ClrOverloadBuilder.cs, ClrOverloadBuilder.EmitConvertToPhp:
switch (Type.GetTypeCode(type))
{
case TypeCode.Boolean:
return(Expression.Convert(expression, Types.Bool[0]));
// coercion:
case TypeCode.SByte:
case TypeCode.Int16:
case TypeCode.Byte:
case TypeCode.UInt16:
case TypeCode.Int32:
return(Expression.Convert(expression, Types.Int[0]));
case TypeCode.Int64:
case TypeCode.UInt32:
return(Expression.Convert(expression, Types.LongInt[0]));
case TypeCode.UInt64:
case TypeCode.Single:
case TypeCode.Double:
return(Expression.Convert(expression, Types.Double[0]));
case TypeCode.Char:
return(Expression.Call(Expression.Convert(expression, Types.Object[0]), Methods.Object_ToString));
case TypeCode.DBNull:
return(Expression.Constant(null, Types.Object[0]));
}
// value type -> ClrValue<T>
// ref type -> ClrObject
return(Expression.Call(null,
type == Types.Object[0] ?
Methods.ClrObject_WrapDynamic : // expression can represent anything, check type in run time and wrap dynamically
Methods.ClrObject_WrapRealObject, // expression is surely not PHP primitive type, DObject nor byte[], wrap into ClrObject or IClrValue
Expression.Convert(expression, Types.Object[0])));
}