private static readonly IDictionary<string, Func<Span, int, Token>>
TokenFactories = new Dictionary<string, Func<Span, int, Token>>
{
{MoveLeftToken.Token, (span, index) => new MoveLeftToken(span, index)},
{MoveRightToken.Token, (span, index) => new MoveRightToken(span, index)},
{BeginLoopToken.Token, (span, index) => new BeginLoopToken(span, index)},
{EndLoopToken.Token, (span, index) => new EndLoopToken(span, index)},
{IncrementToken.Token, (span, index) => new IncrementToken(span, index)},