BadWhileNodeTransformer.cs

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using BadScript2.Common;
using BadScript2.Parser.Expressions;
using BadScript2.Runtime;
using BadScript2.Runtime.Error;
using BadScript2.Runtime.Objects;
using BadScript2.Runtime.Objects.Native;
 
using HtmlAgilityPack;
 
namespace BadHtml.Transformer;
 
public class BadWhileNodeTransformer : BadHtmlNodeTransformer
{
    protected override bool CanTransform(BadHtmlContext context)
    {
        return context.InputNode.Name == "bs:while";
    }
 
    private static bool Evaluate(BadHtmlContext context, HtmlAttribute attribute, BadExpression[] expressions)
    {
        BadSourcePosition pos = context.CreateAttributePosition(attribute);
        BadObject resultObj = context.Execute(expressions, pos);
 
        if (resultObj is not IBadBoolean result)
        {
            throw BadRuntimeException.Create(
                context.ExecutionContext.Scope,
                "Result of 'test' attribute in 'bs:if' node is not a boolean",
                pos
            );
        }
 
        return result.Value;
    }
 
    protected override void TransformNode(BadHtmlContext context)
    {
        HtmlAttribute? conditionAttribute = context.InputNode.Attributes["test"];
 
        if (conditionAttribute == null)
        {
            throw BadRuntimeException.Create(
                context.ExecutionContext.Scope,
                "Missing 'test' attribute in 'bs:if' node",
                context.CreateOuterPosition()
            );
        }
 
        if (string.IsNullOrEmpty(conditionAttribute.Value))
        {
            throw BadRuntimeException.Create(
                context.ExecutionContext.Scope,
                "Empty 'test' attribute in 'bs:if' node",
                context.CreateAttributePosition(conditionAttribute)
            );
        }
 
        BadExpression[] expressions =
            context.Parse(conditionAttribute.Value, context.CreateAttributePosition(conditionAttribute));
 
        while (Evaluate(context, conditionAttribute, expressions))
        {
            using BadExecutionContext loopContext = new BadExecutionContext(
                context.ExecutionContext.Scope.CreateChild(
                    "bs:while",
                    context.ExecutionContext.Scope,
                    null,
                    BadScopeFlags.Breakable | BadScopeFlags.Continuable
                )
            );
 
            foreach (HtmlNode? child in context.InputNode.ChildNodes)
            {
                BadHtmlContext childContext = context.CreateChild(child, context.OutputNode, loopContext);
 
                Transform(childContext);
            }
        }
    }
}