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#stdlib
- k
kirillrakhman
04/18/2016, 7:23 PMMost of the time the code turns out less elegant than you think. Whenever you want to use something like this, better extract the whole thing into a helper method. For example File.existingOrNull()👍 2 - u
uhe
04/18/2016, 7:26 PMyeah maybe we should practice moderation when it comes to this - o
orangy
04/18/2016, 7:31 PM@kirillrakhman: though
is way too wrong simple smile File system is async in nature, so such function doesn’t make any senseFile.existingOrNull - k
kirillrakhman
04/18/2016, 7:37 PMYeah, but when you write to Android's private storage, that's better than catching FikeNotFoundExceptions every time - o
orangy
04/18/2016, 7:44 PMWell, if storage is accessible only by your app, then maybe. Otherwise you will still get FileNotFoundException and will be quite unsure “how did that happen?!" - o
orangy
04/18/2016, 7:46 PMI’d may be use
and then catch exception in the function. 🤔 Not sure…withFileOrNull(fileName) { file-> … } - k
kirillrakhman
04/18/2016, 11:43 PMYes, I'm the only process with writing permissions and I'm catching IOExceptions anyway. I see File.exists as a way to reduce exceptions, not exclude them. - d
dimsuz
05/04/2016, 5:51 PMIs there a good idiom to generate sql placeholders dynamically with stdlib? E.g. I have a
and forcount: Int
I want to create a stringcount = 5"(?,?,?,?,?)" - v
vmironov
05/04/2016, 5:52 PMCopy codeArray(count, { "?" }).joinToString(",", "(", ")”)👎 1👍 1 - o
orangy
05/04/2016, 5:54 PMSomething like"(${"?,".repeat(count - 1)}?)" - d
dimsuz
05/04/2016, 5:54 PMthanks to both of you! I searched for something like
, forgot aboutgeneraterepeat - i
ilya.gorbunov
05/04/2016, 5:58 PMwith less question marks duplication:"?".repeat(count).asIterable().joinToString(",", "(", ")") - d
dimsuz
05/04/2016, 5:59 PMin android-land we tend to dislike extra allocations (looking at
) simple smile but depends on context of course...asIterable() - o
orangy
05/04/2016, 6:13 PMWell, if you want performance and less allocs, then you probably want to pre-calculate size of
and use it to build a string. And use loop instead of iterable.StringBuilder - s
sreich
05/04/2016, 6:51 PMthere's file input stuff..but not output? confusedface - l
loganj
05/05/2016, 2:43 PMif you’re creating SQL query strings in a tight loop, you probably have bigger performance problems. - d
dimsuz
05/05/2016, 2:45 PMyeah, right simple smile it's more of a habit now to always think about allocations, can't help it. - d
dean
05/05/2016, 2:54 PMI think a string extension function would be cool to have in the stdlib:inline operator fun get(range: IntRange): String = substring(range)➕ 3 - e
evanchooly
05/05/2016, 3:12 PMwhy not just use substring? - s
sreich
05/05/2016, 3:15 PMbecause then you get the operator - s
sreich
05/05/2016, 3:16 PM"stuff"[0..4] - s
sreich
05/05/2016, 3:16 PM(i think) - e
evanchooly
05/05/2016, 3:16 PMoh, i missed the operator bit. - e
evanchooly
05/05/2016, 3:18 PMyep. you’d get exactly that. - v
voddan
05/05/2016, 4:23 PM@dean: such an operator has been been discussed for strings and collections some time ago. Try
It was decided not to use an operator because of its obscurity (remember that first time you googled "what the hell does 15-1 mean in python" )."stuff".slice(0..4) - s
sreich
05/05/2016, 5:13 PMargh, so true! - d
dean
05/05/2016, 6:59 PMFair point... Haha - s
sreich
05/05/2016, 7:00 PMwhat was worse with the python operator, i didn't know how to google it - s
sreich
05/05/2016, 7:01 PMbecause google used to be good, but now it's terrible for googling for symbols - s
sreich
05/05/2016, 7:01 PMeven if you surround something i quotes and write "-1" it just ignores you. it really frustrates me