internal override bool IsDeeplyCopied(CopyReason reason, int nestingLevel)
{
switch (operation)
{
// respective operators returns immutable values:
case Operations.Plus:
case Operations.Minus:
case Operations.LogicNegation:
case Operations.BitNegation:
case Operations.Int8Cast:
case Operations.Int16Cast:
case Operations.Int32Cast:
case Operations.Int64Cast:
case Operations.UInt8Cast:
case Operations.UInt16Cast:
case Operations.UInt32Cast:
case Operations.UInt64Cast:
case Operations.DecimalCast:
case Operations.DoubleCast:
case Operations.FloatCast:
case Operations.StringCast:
case Operations.UnicodeCast:
case Operations.BoolCast:
case Operations.UnsetCast:
case Operations.Clone:
case Operations.Print:
return(false);
// respective operators don't do a deep copy:
case Operations.ObjectCast:
case Operations.ArrayCast:
case Operations.BinaryCast:
return(true);
// the result depends on what follows @:
case Operations.AtSign:
return(expr.IsDeeplyCopied(reason, nestingLevel));
default:
throw null;
}
}
/// <summary>
/// Emits IL instructions that makes a copy of variable placed on the top of evaluation stack.
/// </summary>
/// <param name="reason">Reason of the copy.</param>
/// <param name="expression">The <see cref="PHP.Core.AST.Expression"/> to be copied.</param>
/// <remarks>
/// The variable's value is expected on the top of evaluation stack.
/// Calls <see cref="PHP.Core.PhpVariable.Copy"/> method to process the value copying.
/// The result is left on the evaluation stack.
/// </remarks>
public void EmitVariableCopy(CopyReason reason, Expression expression)
{
// checks whether to make a deep copy; starts with level of nesting set to 0:
if (expression == null || expression.IsDeeplyCopied(reason, 0))
{
// First parameter should already be placed on the evaluation stack
il.LdcI4((int)reason);
il.Emit(OpCodes.Call, Methods.PhpVariable.Copy);
}
}
// obsolete:
//internal override bool TryEvaluate(out object value)
//{
// object o;
// if (condExpr.TryEvaluate(out o))
// {
// return (Convert.ObjectToBoolean(o)) ? trueExpr.TryEvaluate(out value) : falseExpr.TryEvaluate(out value);
// }
// else
// {
// value = null;
// return false;
// }
//}
#endregion
internal override bool IsDeeplyCopied(CopyReason reason, int nestingLevel)
{
return((trueExpr ?? condExpr).IsDeeplyCopied(reason, nestingLevel) || falseExpr.IsDeeplyCopied(reason, nestingLevel));
}