aspclassic-core/AspClassic.VBScript/Binders/VBScriptGetIndexBinder.cs
Jelle Luteijn 484dbfc9d9 progress
2022-05-15 11:19:49 +02:00

67 lines
2.3 KiB
C#

using System;
using System.Collections.Generic;
//using System.Text;
using System.Reflection;
using System.Dynamic;
#if USE35
using AspClassic.Scripting.Ast;
using AspClassic.Scripting.ComInterop;
#else
using System.Linq;
using System.Linq.Expressions;
using AspClassic.Scripting.ComInterop;
#endif
using Dlrsoft.VBScript.Runtime;
namespace Dlrsoft.VBScript.Binders
{
public class VBScriptGetIndexBinder : GetIndexBinder
{
public VBScriptGetIndexBinder(CallInfo callinfo)
: base(callinfo)
{
}
public override DynamicMetaObject FallbackGetIndex(
DynamicMetaObject target, DynamicMetaObject[] indexes,
DynamicMetaObject errorSuggestion)
{
#if !SILVERLIGHT
// First try COM binding.
DynamicMetaObject result;
if (ComBinder.TryBindGetIndex(this, target, indexes, out result))
{
return result;
}
#endif
// Defer if any object has no value so that we evaulate their
// Expressions and nest a CallSite for the InvokeMember.
if (!target.HasValue || indexes.Any((a) => !a.HasValue))
{
var deferArgs = new DynamicMetaObject[indexes.Length + 1];
for (int i = 0; i < indexes.Length; i++)
{
deferArgs[i + 1] = indexes[i];
}
deferArgs[0] = target;
return Defer(deferArgs);
}
var restrictions = RuntimeHelpers.GetTargetArgsRestrictions(
target, indexes, false);
if (target.HasValue && target.Value == null)
{
return errorSuggestion?? RuntimeHelpers.CreateThrow(target,
indexes,
restrictions,
typeof(NullReferenceException),
"Object reference not set to an instance of an object.");
}
var indexingExpr = RuntimeHelpers.EnsureObjectResult(
RuntimeHelpers.GetIndexingExpression(target,
indexes));
return new DynamicMetaObject(indexingExpr, restrictions);
}
}
}