using CanonSharp.Combinator.Abstractions;

namespace CanonSharp.Combinator.Parsers.Bases;

/// <summary>
/// 单子解析器
/// </summary>
/// <param name="parser">上游解析器</param>
/// <param name="next">下游解析器生成函数</param>
/// <typeparam name="TToken">输入流类型</typeparam>
/// <typeparam name="TIntermediate">上游解析器结果类型</typeparam>
/// <typeparam name="T">下游解析器结果类型</typeparam>
internal sealed class BindParser<TToken, TIntermediate, T>(
    Parser<TToken, TIntermediate> parser,
    Func<TIntermediate, Parser<TToken, T>> next) : Parser<TToken, T>
{
    internal override ParseResult<TToken, TResult> Run<TState, TResult>(TState state,
        Func<ParseResult<TToken, T>, ParseResult<TToken, TResult>> continuation)
        => parser.Run(state, result => result.Next(next, continuation));
}