using Convention.RScript.Parser;
using System.Diagnostics.CodeAnalysis;

namespace Convention.RScript.Runner
{
    public class EnterNamespaceRunner : IRSentenceRunner
    {
        [return: MaybeNull]
        public object Run(ExpressionParser parser, RScriptSentence sentence, RScriptContext context)
        {
            // 准备记录当前命名空间中定义的变量, 清空上层命名空间的变量
            context.CurrentLocalSpaceVariableNames.Push(new());
            // 更新变量值
            foreach (var (varName, varValue) in parser.context.Variables)
            {
                context.Variables.SetValue(varName, varValue);
            }
            // 压栈
            context.RuntimePointerStack.Push(context.CurrentRuntimePointer);
            return null;
        }
    }
}