Comment by cessor | Hacker News Reader

Comment by cessor | Hacker News Reader

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Also Java:

bank.move(new Amount(100), new FromAccount(checkingAccount), new ToAccount(savingsAccount));

If you are really trying, you will be able to convey enough information so that your fellow programmer. will understand what you are trying to accomplish. Unfortunately, in practice, even Java Experts will convey to you that this style is wrong, classes and objects are " too expensive", primitive values are fine, and that this is too verbose.*

I learned about this style from Yegor Bugayenko's Book "Elegant Objects", go check it out. https://www.elegantobjects.org/

*) Yes, Java is verbose; not trying to defend that. I am very happy about keyword arguments in Python, for example. But, as soon as you have classes, ctors, objects, you can use them to add rich semantics into your code. Works with functional languages and other, better typesystems, too.

Of course you can, but you can't simply hand-wave away the verbosity. What a language makes easy is usually more important than what it makes possible.

In Python, adding from=from_account, to=to_account to clarify a call is basically free; you don't have to change the callee and you don't have to change any other call sites.

> What a language makes easy is usually more important than what it makes possible.

very well said

I think you don't have enough factories.

bank.move(new Amount(100), AccountChannelFactory.create(AccountChannelFactory.CHECKING_CHANNEL, checkingAccount), AccountChannelFactory.create(AccountChannelFactory.SAVINGS_CHANNEL, savingsAccount));

I wouldn't write it either way. I would write something like bank.processTransfer(new Transfer(100, checkingAccount, savingsAccount)) where the transfer object is immutable.

Cool, but the SmallTalk example requires a lot less squinting which is nice.

Is there an explanation that doesn’t require buying a $40 book? I searched the site and couldn’t find anything

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