4 ms·

'Many' is the weasel word here.

stephengillie 9y ago
There's an anti-pattern where a function will be declared entirely in a callback, instead of declaring the function in another location and referencing it locally. It's difficult to read and logically follow. This seems especially common in Javascript. Is it just a sign of novice?
- yen223 9y ago
  Declaring the function in another location is the antipattern. Code locality is important for being able to maintain contextual information when reading code. Declaring a callback in a different location from where it's used means one extra level of indirection for no good reason. Also, not sure how this is relevant to anything.
  - stephengillie 9y ago
    Declaring functions in another location is the purpose of functions, yes? Otherwise we would code in a purely linear fashion. Some code locality should be sacrificed for readability, reuse, and clarity. Not to make a "forest of functions", but to define separate ideas more clearly than stuffing one thought into a parameter of another thought. It's like if I was telling you about something funny that happened when I got to work, but first I have to describe every detail of my drive to work... It's a thread on ineffective coding habits, so I thought I would piggyback with a general question. I regrettably did not pursue an undergrad CS degree, and so sometimes wonder about the gaps in my education such a degree would have filled. Thank you for your time.
    - Roboprog 9y ago
      If the function is large, sure, make it into it's own name thing (with as restricted a scope as you can get away with). However, many languages support callbacks/lambdas/closures/blocks as parameters to generic library code, and these dangly bits are often one or two lines. E.g. (pseudo-code) - * list.for-each : print * list.filter : is-wanted * db-connection.bracket-transaction : compound-update This allows you to use, or create your own, library code as extensions of the language to reduce boiler-plate code for visiting, filtering, resource management, etc. Have a look at something like the Ruby language to see how this is exploited to reduce A LOT of code noise.
      - Roboprog 9y ago
        Some might also argue that "private methods", which are visible to every other method in a class, are a bad thing, rather than making a nested function within the only function / method that used said code. One of the things I used to be able to do in Pascal, that C ... Java and their ilk took away. Fortunately, most FP languages gave that back, with interest (closures).
        int_19h 9y ago
        C# just got true nested functions back in 7.0. Although, as you have said, it is somewhat redundant with closures, and even more so with local type inference. C++, C# and Java all let you do what effectively amounts to a local function these days.
- jhomedall 9y ago
  In many cases the function passed in will not make any sense outside of the context in which it is used. For example, consider: const kittenNames = cats.flatMap(cat => cat.kittens) .map(kitten => kitten.name); In this case, what would be gained by extracting the two inline functions?
arwhatever 9y ago
I've been able to use F# at work for a few months now and I'm absolutely enamored with it. But I have not yet had any of what I call "ints, strings,and for loops-only developers," the folks who never really grasped O.O. very well at all, contribute to the code. I'll be eager see how that goes.
- Roboprog 9y ago
  Good point. Most of these "look how much better we did with X tool" comparisons usually have a strong sample bias in that the X team are highly motivated and talented. X probably does help them quite a bit, but perhaps not as much as indicated, especially once the thinks-in-Blub (and loves it!) lumpen-programmers get added to the project :-( I'd really like to move out of 1960s tech into 1970s tech, someday (e.g. - from Simula-67-inspired to Scheme/Smalltalk-inspired environments)
- hardlianotion 9y ago
  I am very enthused about functional languages like F# - don't know much about F# particularly and respect rather than love C#. I just find comparisons of this kind slightly off-putting. It's always an interesting time when you share your lovely clean concept with potential philistines - hope your project's exposure to your loop-community goes well.

There's an anti-pattern where a function will be declared entirely in a callback, instead of declaring the function in another location and referencing it locally. It's difficult to read and logically follow. This seems especially common in Javascript. Is it just a sign of novice?

yen223 9y ago
Declaring the function in another location is the antipattern. Code locality is important for being able to maintain contextual information when reading code. Declaring a callback in a different location from where it's used means one extra level of indirection for no good reason. Also, not sure how this is relevant to anything.
- stephengillie 9y ago
  Declaring functions in another location is the purpose of functions, yes? Otherwise we would code in a purely linear fashion. Some code locality should be sacrificed for readability, reuse, and clarity. Not to make a "forest of functions", but to define separate ideas more clearly than stuffing one thought into a parameter of another thought. It's like if I was telling you about something funny that happened when I got to work, but first I have to describe every detail of my drive to work... It's a thread on ineffective coding habits, so I thought I would piggyback with a general question. I regrettably did not pursue an undergrad CS degree, and so sometimes wonder about the gaps in my education such a degree would have filled. Thank you for your time.
  - Roboprog 9y ago
    If the function is large, sure, make it into it's own name thing (with as restricted a scope as you can get away with). However, many languages support callbacks/lambdas/closures/blocks as parameters to generic library code, and these dangly bits are often one or two lines. E.g. (pseudo-code) - * list.for-each : print * list.filter : is-wanted * db-connection.bracket-transaction : compound-update This allows you to use, or create your own, library code as extensions of the language to reduce boiler-plate code for visiting, filtering, resource management, etc. Have a look at something like the Ruby language to see how this is exploited to reduce A LOT of code noise.
    - Roboprog 9y ago
      Some might also argue that "private methods", which are visible to every other method in a class, are a bad thing, rather than making a nested function within the only function / method that used said code. One of the things I used to be able to do in Pascal, that C ... Java and their ilk took away. Fortunately, most FP languages gave that back, with interest (closures).
      - int_19h 9y ago
        C# just got true nested functions back in 7.0. Although, as you have said, it is somewhat redundant with closures, and even more so with local type inference. C++, C# and Java all let you do what effectively amounts to a local function these days.
jhomedall 9y ago
In many cases the function passed in will not make any sense outside of the context in which it is used. For example, consider: const kittenNames = cats.flatMap(cat => cat.kittens) .map(kitten => kitten.name); In this case, what would be gained by extracting the two inline functions?

arwhatever 9y ago

I've been able to use F# at work for a few months now and I'm absolutely enamored with it. But I have not yet had any of what I call "ints, strings,and for loops-only developers," the folks who never really grasped O.O. very well at all, contribute to the code. I'll be eager see how that goes.

Roboprog 9y ago
Good point. Most of these "look how much better we did with X tool" comparisons usually have a strong sample bias in that the X team are highly motivated and talented. X probably does help them quite a bit, but perhaps not as much as indicated, especially once the thinks-in-Blub (and loves it!) lumpen-programmers get added to the project :-( I'd really like to move out of 1960s tech into 1970s tech, someday (e.g. - from Simula-67-inspired to Scheme/Smalltalk-inspired environments)
hardlianotion 9y ago
I am very enthused about functional languages like F# - don't know much about F# particularly and respect rather than love C#. I just find comparisons of this kind slightly off-putting. It's always an interesting time when you share your lovely clean concept with potential philistines - hope your project's exposure to your loop-community goes well.