public static Expression ParseExpression(ExpressionWalker ew, Type caller = null)
{
Expression ret = null;
_retry:
bool isOperatorCall = caller == typeof(OperatorExpression) || caller == typeof(RightOperatorExpression) || caller == typeof(ForeachExpression);
var current = ew.Current.Token;
if (current == ExpressionToken.Literal)
{
//cases like variable(.., variable[.., variable + .., variable
if (ew.HasNext)
{
var peak = ew.PeakNextOrThrow().Token;
if (peak == ExpressionToken.LeftParen)
{
ret = CallExpression.Parse(ew);
}
else if (peak == ExpressionToken.Period && caller != typeof(IdentityExpression) && caller != typeof(InteractableExpression))
{
ret = IdentityExpression.Parse(ew);
}
else if (peak == ExpressionToken.LeftBracet)
{
ret = IndexerCallExpression.Parse(ew);
}
else if (peak == ExpressionToken.New)
{
ret = NewExpression.Parse(ew);
}
else if (RightOperatorExpression.IsNextAnRightUniOperation(ew, caller) && caller != typeof(RightOperatorExpression))
{
ret = RightOperatorExpression.Parse(ew);
}
else if (OperatorExpression.IsNextAnOperation(ew) && !isOperatorCall)
{
ret = OperatorExpression.Parse(ew);
}
else
{
ret = IdentityExpression.Parse(ew, caller);
}
}
else
{
ret = IdentityExpression.Parse(ew, caller);
}
}
else if (LeftOperatorExpression.IsCurrentAnLeftUniOperation(ew))
{
ret = LeftOperatorExpression.Parse(ew);
}
else if (current == ExpressionToken.NumberLiteral)
{
ret = NumberLiteral.Parse(ew);
}
else if (current == ExpressionToken.StringLiteral)
{
ret = StringLiteral.Parse(ew);
}
else if (current == ExpressionToken.LeftParen)
{
ret = GroupExpression.Parse(ew, ExpressionToken.LeftParen, ExpressionToken.RightParen);
}
else if (current == ExpressionToken.LeftBracet)
{
ret = ArrayExpression.Parse(ew);
}
else if (current == ExpressionToken.New)
{
ret = NewExpression.Parse(ew);
}
else if (current == ExpressionToken.Boolean)
{
ret = BooleanLiteral.Parse(ew);
}
else if (current == ExpressionToken.CharLiteral)
{
ret = CharLiteral.Parse(ew);
}
else if (current == ExpressionToken.Throw)
{
ret = ThrowExpression.Parse(ew);
}
else if (current == ExpressionToken.Hashtag && ew.HasNext && ew.PeakNext.Token == ExpressionToken.NumberLiteral)
{
ret = HashtagReferenceExpression.Parse(ew, caller);
}
else if (current == ExpressionToken.Null)
{
ret = NullIdentity.Parse(ew);
}
else if (current == ExpressionToken.NewLine)
{
ew.NextOrThrow();
goto _retry;
}
else
{
throw new UnexpectedTokenException($"Token was not expected to be a {ew.Current.Token}");
}
//here we parse chained math operations
while (OperatorExpression.IsCurrentAnOperation(ew) && !isOperatorCall)
{
if (RightOperatorExpression.IsCurrentAnRightUniOperation(ew) && caller != typeof(OperatorExpression))
{
ret = RightOperatorExpression.Parse(ew, ret);
}
else if (OperatorExpression.IsCurrentAnOperation(ew))
{
ret = OperatorExpression.Parse(ew, ret);
}
}
return(ret);
}