Simple apply/filter/reduce package in Go
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Simple apply/filter/reduce package in Go
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Re: Simple apply/filter/reduce package in Go
#2But you can't write generic functions in Go!
Oh, wait. He just did.
As a caveat to my exasperated sarcasm, I do realize he's using reflection to identify and type the data at runtime, as opposed to compile time as with C++ templating, but this is kind of generalization is still quite useful when writing general purpose library code.
Personally, I'd not be inclined to use this either, the number of times I've actually had to write generic code using reflect in my time writing Go could be counted with one finger.
I do appreciate that it's there, however, since it is what allows the JSON library to do its magic.
Re: Simple apply/filter/reduce package in Go
#3But you can't write generic functions in Go! Oh, wait. He just did. As a caveat to my exasperated sarcasm, I do realize he's using reflection to identify and type the data at runtime, as opposed to compile time as with C++ templating, but this is kind of generalization is still quite useful when writing general purpose library code. Personally, I'd not be inclined to use this either, the number of times I've actually…
Yeah, my immediate reaction was, "all that work manually doing what a type checker should have done for you?" Given that, it seems sensible enough to just inline and type-specialize the 5 or so lines you actually care about.
Re: Simple apply/filter/reduce package in Go
#4I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
Re: Simple apply/filter/reduce package in Go
#5To see the docs, use godoc.org, copy/paste the full URL for the repo into the search, and you get this[0]. Nicer way to see the API for the package.
Re: Simple apply/filter/reduce package in Go
#6I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
In most languages, the for loop ends up being faster. Sometimes noticeably so. Me, I generally start with declarative syntax, but the profiler frequently tells me to go back and change it.
Being a systems programmer, wonder if it's easier for him to just use the for loop as a default. Performance demands are always high in systems programming (because there'll be a whole stack of additional software standing on top of your code and depending on it for performance), so one might end up needing to use for loops often enough that it's easier to just use them all the time for consistency's sake.
Re: Simple apply/filter/reduce package in Go
#7I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
It's easy to dismiss an opinion but that doesn't mean it's wrong. For example, if you like filter/reduce you may criticize languages that don't encourage it (Go, Python, etc). But often this leads to copying ideas from one language resulting in code that's hard to maintain in another language which encourages different ways of expressing the same logic.
Re: Simple apply/filter/reduce package in Go
#8I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
In most languages, the for loop ends up being faster. Sometimes noticeably so. Me, I generally start with declarative syntax, but the profiler frequently tells me to go back and change it. Being a systems programmer, wonder if it's easier for him to just use the for loop as a default. Performance demands are always high in systems programming (because there'll be a whole stack of additional software standing on top o…
That's the essence of Clojure's transducers http://clojure.org/transducers
...they give you the declarative syntax of filter/reduce/etc but can have the same evaluation strategy as for loops, with comparable performance.
Re: Simple apply/filter/reduce package in Go
#9I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
Debugging. Try debugging a Select/Where stream in C#; it is a PITA. I often find myself unwinding my list comprehensions into for loops because I need to debug.
There is a reason Haskell's type system has to be so strong :)
Re: Simple apply/filter/reduce package in Go
#10I don't get why someone would rather write a for loop than use declarative data syntax. If I want to get the names of all administrators doing `users.Where(user => user.isAdmin()).Select(user => user.Name)` is so much nicer than using a for loop - or maybe he's suggesting we start writing FOR loops instead of SQL for our databases too?
It's easy to dismiss an opinion but that doesn't mean it's wrong. For example, if you like filter/reduce you may criticize languages that don't encourage it (Go, Python, etc). But often this leads to copying ideas from one language resulting in code that's hard to maintain in another language which encourages different ways of expressing the same logic.
filter and reduce are both builtins in Python and I see nothing discouraging anyone from taking full advantage of them.