static Expression BindAccess(Expression expr, Expression ctx, AccessMask access, Expression rvalue)
{
if (access.EnsureObject())
{
if (expr.Type == typeof(PhpAlias))
{
// ((PhpAlias)fld).EnsureObject()
expr = Expression.Call(expr, Cache.Operators.PhpAlias_EnsureObject);
}
else if (expr.Type == typeof(PhpValue))
{
// ((PhpValue)fld).EnsureObject()
expr = Expression.Call(expr, Cache.Operators.PhpValue_EnsureObject);
}
else
{
// getter // TODO: ensure it is not null
Debug.Assert(!expr.Type.GetTypeInfo().IsValueType);
}
}
else if (access.EnsureArray())
{
if (expr.Type == typeof(PhpAlias))
{
// ((PhpAlias)fld).EnsureArray()
expr = Expression.Call(expr, Cache.Operators.PhpAlias_EnsureArray);
}
else if (expr.Type == typeof(PhpValue))
{
// ((PhpValue)fld).EnsureArray()
expr = Expression.Call(expr, Cache.Operators.PhpValue_EnsureArray);
}
else if (expr.Type == typeof(PhpArray))
{
// (PhpArray)fld // TODO: ensure it is not null
}
else
{
// Operators.EnsureArray( fld )
// TODO: string
expr = Expression.Call(Cache.Operators.Object_EnsureArray, expr);
}
}
else if (access.EnsureAlias())
{
if (expr.Type == typeof(PhpAlias))
{
// (PhpAlias)getter
}
else if (expr.Type == typeof(PhpValue))
{
// ((PhpValue)fld).EnsureAlias()
expr = Expression.Call(expr, Cache.Operators.PhpValue_EnsureAlias);
}
else
{
// getter // cannot read as reference
}
}
else if (access.WriteAlias())
{
// write alias
Debug.Assert(rvalue.Type == typeof(PhpAlias));
rvalue = ConvertExpression.Bind(rvalue, typeof(PhpAlias), ctx);
if (expr.Type == typeof(PhpAlias))
{
// ok
}
else if (expr.Type == typeof(PhpValue))
{
// fld = PhpValue.Create(alias)
rvalue = Expression.Call(typeof(PhpValue).GetMethod("Create", Cache.Types.PhpAlias), rvalue);
}
else
{
// fld is not aliasable
Debug.Assert(false, "Cannot assign aliased value to field of type " + expr.Type.ToString());
rvalue = ConvertExpression.Bind(rvalue, expr.Type, ctx);
}
expr = Expression.Assign(expr, rvalue);
}
else if (access.Unset())
{
Debug.Assert(rvalue == null);
expr = Expression.Assign(expr, ConvertExpression.BindDefault(expr.Type));
}
else if (access.Write())
{
// write by value
if (expr.Type == typeof(PhpAlias))
{
// Template: fld.Value = (PhpValue)value
expr = Expression.Assign(Expression.Field(expr, Cache.PhpAlias.Value), ConvertExpression.Bind(rvalue, typeof(PhpValue), ctx));
}
else if (expr.Type == typeof(PhpValue))
{
// Template: Operators.SetValue(ref fld, (PhpValue)value)
expr = Expression.Call(Cache.Operators.SetValue_PhpValueRef_PhpValue, expr, ConvertExpression.Bind(rvalue, typeof(PhpValue), ctx));
}
else
{
// Template: fld = value
// default behaviour by value to value
expr = Expression.Assign(expr, ConvertExpression.Bind(rvalue, expr.Type, ctx));
}
}
else if (access.ReadValue())
{
// dereference
if (expr.Type == typeof(PhpValue))
{
// Template: value.GetValue().DeepCopy()
expr = Expression.Call(expr, Cache.Operators.PhpValue_GetValue);
}
else if (expr.Type == typeof(PhpAlias))
{
// Template: alias.Value // expecting alias cannot be null ref
expr = Expression.Field(expr, Cache.PhpAlias.Value);
}
}
else if (access.ReadValueCopy())
{
// dereference & copy
if (expr.Type == typeof(PhpValue))
{
// Template: value.GetValue().DeepCopy()
expr = Expression.Call(Expression.Call(expr, Cache.Operators.PhpValue_GetValue), Cache.Operators.PhpValue_DeepCopy);
}
else if (expr.Type == typeof(PhpAlias))
{
// TODO: specify - ReadCopy | ReadValue | ReadValueCopy - currently not consistent
}
}
else if (access.Isset())
{
if (expr.Type == typeof(PhpAlias))
{
expr = Expression.Field(expr, Cache.PhpAlias.Value);
}
//
if (expr.Type == typeof(PhpValue))
{
// Template: Operators.IsSet( value )
expr = Expression.Call(Cache.Operators.IsSet_PhpValue, expr);
}
else if (!expr.Type.GetTypeInfo().IsValueType)
{
// Template: value != null
expr = Expression.ReferenceNotEqual(expr, Expression.Constant(null, typeof(object)));
}
else
{
// if there is bound typed symbol, it is always set:
expr = Expression.Constant(true, typeof(bool));
}
}
// Read, IsSet
return(expr);
}