Index can be useful but start looking for mapping and sorting functions. Or foreach. If you really must index, sure go use index or I if it’s conventionally understood. But reading something like for I in e where p == r.status is really taxing to make sense of
Honest question: is there a mapping function that handles the case where you need to loop through an iterable, and conditionally reference an item one or two steps ahead in the iterable?
Something like parsing a string that could have command codes in it of varying length. So I guess the difference is, is this a 1-, 2-, or 3-character code?
I have something like this in a barcode generator and I keep trying to find a way to make it more elegant, but I keep coming back to index and offset as the simplest and most understandable approach.
This would map arr and return halved values for elements for which the element two steps ahead is even. This should be available in languages where map is present. And sorry for possible typos, writing this on mobile.
Oh yeah, I map, filter and reduce pretty much everywhere I can. But sometimes you need the index and i is so commonly understood to be that, I’d say it could even be less legible to deviate from that convention
It’s not incoherent, it just takes a tiny bit more effort to mentally parse as it’s not a stereotypical for loop. Maybe it’s just me, but let me try and explain
With the i example if you’re familiar enough with a language, your brain will gloss over the unimportant syntax, you go straight to the comparison and then whether it’s incrementing or decrementing.
With the other example, the first my brain did was notice it’s not following convention, which then pushes me to read the line carefully as there is probably a reason it doesn’t.
I’m not saying it’s a huge difference or anything, but following code conventions like this makes things like code reviews much easier cumulatively.
Index can be useful but start looking for mapping and sorting functions. Or foreach. If you really must index, sure go use index or I if it’s conventionally understood. But reading something like for I in e where p == r.status is really taxing to make sense of
Honest question: is there a mapping function that handles the case where you need to loop through an iterable, and conditionally reference an item one or two steps ahead in the iterable?
In Haskell, you could do something like
map (\(thisItem, nextItem) -> …) (zip list (tail list))Not that I’m aware of but that’s a condition where you’re thinking with an index. What’s the difference you’re looking for?
Something like parsing a string that could have command codes in it of varying length. So I guess the difference is, is this a 1-, 2-, or 3-character code?
I have something like this in a barcode generator and I keep trying to find a way to make it more elegant, but I keep coming back to index and offset as the simplest and most understandable approach.
So you could generate lists of 1, 2, and 3 character code items rather than looking at index +1 or something.
In js there’s reduce. Something like
arr.reduce((result, currentValue, currentIndex, original) => { if(currentIndex < original.length - 2 && original[currentIndendex + 2] % 2 === 0 ) { result.push(currentValue / 2) } else { result.push(currentValue); } return result; }, [])This would map arr and return halved values for elements for which the element two steps ahead is even. This should be available in languages where map is present. And sorry for possible typos, writing this on mobile.
Oh yeah, I map, filter and reduce pretty much everywhere I can. But sometimes you need the index and
iis so commonly understood to be that, I’d say it could even be less legible to deviate from that conventionIn what world is
for (int index = 0; index < objectToIterate; index++) { // DO YO THANG }less coherent than
for (int i; i < objectToIterate; i++) { // DO YO THANG }The world where the convention is
iWhat’s incoherent about the first one? Why is index bad beyond standards
It’s not incoherent, it just takes a tiny bit more effort to mentally parse as it’s not a stereotypical for loop. Maybe it’s just me, but let me try and explain
With the
iexample if you’re familiar enough with a language, your brain will gloss over the unimportant syntax, you go straight to the comparison and then whether it’s incrementing or decrementing.With the other example, the first my brain did was notice it’s not following convention, which then pushes me to read the line carefully as there is probably a reason it doesn’t.
I’m not saying it’s a huge difference or anything, but following code conventions like this makes things like code reviews much easier cumulatively.