Hacker News Reader

Comment by padseeker | Hacker News Reader

Just read the article. A big part of the article that I can summarize is I don't set the requirements, someone else does. Every project is different. You might be fine with just integers. However I've been tasked with much more complicated requests.

There may be exceptions but I guarantee you in most cases the product manager doesn't want the letter e.

My app was built with Rails, and if you enter the value "3.9e3" which represents the number 3900, Ruby will simply use the number 3 and toss the rest of the value away. Do you really want to add special functionality on the back end to covert that value into the actual value? I surely would not.

Also plenty of people use javascript without it being a Single Page Application. Keenforms is not a SPA, we use React for certain pages, but I wanted to keep server side rendering. Using Javascript is not exclusive to SPAs.

View on HN

(int) ‘3.9e3’ gets parsed correctly in php, perhaps use a language built for the web and not a general purpose language, or a framework that knows how to parse exponential notation? It sounds like Rails doesn’t understand how software works.

I’ve also been messing with forms for twenty-something years, and I’ve never run into these sorts of problems but I understand the problems you are facing, especially after googling these problems and their solution in regards to Rails. I’ve heard it’s a productive language, but when you have to solve such simple problems, maybe not?

Sorry, I don’t mean to bash on your chosen language which is probably how this is coming across. I’m genuinely intrigued by these stack overflow answers.

"Completely change you application stack and learn a new language so you can parse 3.9e3" is not really an option for most people.

thank you so much for this

Just because you didn't run into these problems doesn't mean they don't exist. The clients I do work for have very complicated requirements and expect a lot of dynamic interactions from the forms they pay for. It could be a non profit trying to determine if a new client's family qualifies for federal benefits based on family size and income level. It could be a gas pipeline company trying to calculate how much natural gas they can deliver on a 60 day contract during summer months versus winter months. It could be calculating the medication dosage per body weight for a pharmaceutical company. There was the life insurance example which I mentioned in the article.

Ruby will parse "3.9e3" properly. However Ruby on Rails param parser tries to prevent bad data from entering the system. So the e gets sliced off. There are things that you can do to prevent data from being entered that way.

However like I mentioned in the article and commented on multiple times its not always my choice. And overwhelmingly the product managers and stake holders I interact with would prefer to not see numbers submitted in scientific notation form. There's no reason why you would want to submit your age like that. It's highly unlikely anyone would need a product quantity value in that format.

And maybe most importantly the people who pay tell me all the time they don't want it. Does that make sense?

3.9e3 is equivalent to 3900 in the same way that 3,900 is equivalent to 3900.

So, Ruby’s number parsing is garbage I guess. Hopefully it at least does this properly for floats?

With ROR it might be transformed via the params parser. If you enter the code below in plain old Ruby environment, like irl or the console, it will properly parse it;

"3.9e3".to_f => 3900.0

Something happens when submitting web based params. I'd be curious to see what other back end languages and frameworks do.

This is what happens:

"3.9e3".to_i => 3

and

Integer("3.9e3")

raises "invalid value for Integer()". Really, nothing to see here. Ruby just doesn't treat "3.9e3" as a valid string for an integer (which arguably is correct IMHO)

Some countries use a comma as the decimal point. So it's not obvious to everyone that 3,900 == 3900

Reply on news.ycombinator.com