Blog_JintLiteralExpression.cs

internal class JintLiteralExpression : JintExpression
{
    internal readonly JsValue _cachedValue;

    public JintLiteralExpression(Engine engine, Literal expression) : base(engine, expression)
    {
        _cachedValue = ConvertToJsValue(expression);
    }

    internal static JsValue ConvertToJsValue(Literal literal)
    {
        if (literal.TokenType == TokenType.BooleanLiteral)
        {
            return literal.NumericValue > 0.0 ? JsBoolean.True : JsBoolean.False;
        }

        if (literal.TokenType == TokenType.NullLiteral)
        {
            return JsValue.Null;
        }

        if (literal.TokenType == TokenType.NumericLiteral)
        {
            return JsNumber.Create(literal.NumericValue);
        }

        if (literal.TokenType == TokenType.StringLiteral)
        {
            return JsString.Create((string) literal.Value);
        }

        return null;
    }

    public override JsValue GetValue()
    {
        // need to notify correct node when taking shortcut
        _engine._lastSyntaxNode = _expression;
        return _cachedValue ?? ResolveValue();
    }

    protected override object EvaluateInternal()
    {
        return GetValue();
    }

    private JsValue ResolveValue()
    {
        var expression = (Literal) _expression;
        if (expression.TokenType == TokenType.RegularExpression)
        {
            return _engine.RegExp.Construct((System.Text.RegularExpressions.Regex) expression.Value, expression.Regex.Flags);
        }

        return JsValue.FromObject(_engine, expression.Value);
    }
}