Upsilon/Upsilon/Parser/ExpressionSyntax/IndexExpressionSyntax.cs

using System.Collections.Generic;
using Upsilon.Text;

namespace Upsilon.Parser
{
    public class IndexExpressionSyntax : ExpressionSyntax
    {
        public ExpressionSyntax Expression { get; }
        public SyntaxToken OpenBracket { get; }
        public ExpressionSyntax Index { get; }
        public SyntaxToken CloseBracket { get; }

        public IndexExpressionSyntax(ExpressionSyntax expression, SyntaxToken openBracket, ExpressionSyntax index,
            SyntaxToken closeBracket)
        {
            Expression = expression;
            OpenBracket = openBracket;
            Index = index;
            CloseBracket = closeBracket;
            Span = TextSpan.Between(expression.Span, closeBracket.Span);
        }

        public override SyntaxKind Kind => SyntaxKind.IndexExpression;
        public override IEnumerable<SyntaxNode> ChildNodes()
        {
            yield return Expression;
            yield return OpenBracket;
            yield return Index;
            yield return CloseBracket;
        }
    }

    public class FullStopIndexExpressionSyntax : ExpressionSyntax
    {
        public ExpressionSyntax Expression { get; }
        public SyntaxToken FullStop { get; }
        public IdentifierToken Index { get; }

        public FullStopIndexExpressionSyntax(ExpressionSyntax expression, SyntaxToken fullStop, IdentifierToken index)
        {
            Expression = expression;
            FullStop = fullStop;
            Index = index;
            Span = TextSpan.Between(expression.Span, Index.Span);
        }

        public override SyntaxKind Kind => SyntaxKind.FullStopIndexExpression;
        public override IEnumerable<SyntaxNode> ChildNodes()
        {
            yield return Expression;
            yield return FullStop;
            yield return Index;
        }
    }
}