Kyoo/back/src/Kyoo.Abstractions/Utility/ExpressionParameterReplacer.cs
2023-12-08 02:42:46 +01:00

52 lines
1.6 KiB
C#

// Kyoo - A portable and vast media library solution.
// Copyright (c) Kyoo.
//
// See AUTHORS.md and LICENSE file in the project root for full license information.
//
// Kyoo is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// Kyoo is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Kyoo. If not, see <https://www.gnu.org/licenses/>.
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
namespace Kyoo.Utils;
public sealed class ExpressionArgumentReplacer : ExpressionVisitor
{
private readonly Dictionary<ParameterExpression, Expression> _mapping;
public ExpressionArgumentReplacer(Dictionary<ParameterExpression, Expression> dict)
{
_mapping = dict;
}
protected override Expression VisitParameter(ParameterExpression node)
{
if (_mapping.TryGetValue(node, out Expression? mappedArgument))
return Visit(mappedArgument);
return base.VisitParameter(node);
}
public static Expression ReplaceParams(
Expression expression,
IEnumerable<ParameterExpression> epxParams,
params ParameterExpression[] param
)
{
ExpressionArgumentReplacer replacer =
new(epxParams.Zip(param).ToDictionary(x => x.First, x => x.Second as Expression));
return replacer.Visit(expression);
}
}