Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Left to Right Programming

graic.net

Post reply on HN
Print view View original

61–70 of 372 posts

Re: Left to Right Programming

#61

Post by shadowgovt »

juancn wrote: post #39

SQL shows it's age by having exactly the same problem. Queries should start by the `FROM` clause, that way which entities are involved can be quickly resolved and a smart editor can aid you in writing a sensible query faster. The order should be FROM -> SELECT -> WHERE, since SELECT commonly gives names to columns, which WHERE will reference. You could even avoid crap like `SELECT * FROM table`, and just write `FROM…

It's true. I call authoring SQL "holographic programming" because any change I want to make frequently implies a change to the top and bottom of the query too; there's almost never a localized change.

C++ has this issue too due to the split between header declarations and implementations. Change a function name? You're updating it in the implementation file, and the header file, and then you can start wondering if there are callers that need to be updated also. Then you add in templates and the situation becomes even more fun (does this code live in a .cc file? An .h file? Oh, is your firm one of the ones that does .hh files and/or .hpp files also? Have fun with that).

Re: Left to Right Programming

#63

Post by Twey »

Terr_ wrote: post #54

That's fine for doing algebra in pure functions, but what about destructive commands or interactive scenarios? For example, using "rm" on the command line, or an SQL "delete". I would very much like those short programs to be invalid , until someone provides more detail about what should be destroyed in a way that is accident-resistant. If I had my 'druthers, the left-to-right prefix of "delete from table" would be i…

The solution suggested by the author, I assume, is `table.where(true).delete()` and `all_my_data.rm()`, which indeed has the property you describe.

Re: Left to Right Programming

#64

Post by Twey »

This is the main reason I really like concatenative syntax for languages — this property is _enforced_ for programs (minus some delimited special cases, usually). It also neatly generalizes the special `self` argument so you can dispatch on the types of all the arguments.

Re: Left to Right Programming

#65

Post by feelamee »

> Suppose you have a FILE file and you want to get it’s contents. Ideally, you’d be able to type file. and see a list of every function that is primarily concerned with files. From there you could pick read and get on with your day.

> Instead, you must know that functions releated to FILE tend to start with f, and when you type f the best your editor can do is show you all functions ever written that start with an f

Why do you think that this is a problem of C? no one is stopping your tools from searching `fclose` by first parameter type when you wrote `file.`. Moreover, I know that CLion already do this.

Re: Left to Right Programming

#66

Post by hawk_ »

lo_zamoyski wrote: post #12
hawk_ wrote: post #8

I miss the F# pipe operator ( https://learn.microsoft.com/en-us/dotnet/fsharp/language-ref... ) in other languages. It's so natural to think of function transform pipelines. In other languages you have to keep going to the left and prepend function names, and to the right to add additional args, parens etc ...

n.b. pipe operators also exist in various forms in other languages. OCaml, Elixir, Clojure, Haskell...

Oh yes I didn't mean F# is the only one. Just that the other ones I am likely to work with i.e. C++, Java and Python don't have it.

Re: Left to Right Programming

#68

Post by imtringued »

Zarathruster wrote: post #52

On the other hand, Python does have "from some_library import child_module" which is always nice. In JS we get "import { asYetUnknownModule } from SomeLibrary" which is considerably less helpful.

I never understood this obsession with the keyword "from"

Just do

    import SomeLibrary {
        asYetUnknownModule
    }

Re: Left to Right Programming

#70

Post by AnimalMuppet »

nottorp wrote: post #14
kmoser wrote: post #5

> Programs should be valid as they are typed. That would be nice if devs always wrote code sequentially, i.e. left to right, one character at a time, one line at a time. But the reality is that we often jump around, filling in some things while leaving other things unfinished until we get back to them. Sometimes I'll write code that operates on a variable, then a minute later go back and declare that variable (perhap…

Exactly. You only write code sequentially when it's a new file. If i decide to add a new field to some class, i won't necessarily go to the class definition first, I'll probably write the code using that field because that's where the IDE was when i got the idea. If I want to enhance some condition checking, i'll go through a phase where the piece of code isn't valid while I'm rearranging ifs and elses.

> You only write code sequentially when it's a new file.

Often, not even then.

Post reply on HN