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What does “abstract over” mean?
... = as.foldLeft(z)(f)
}
val sumOfOneTwoThree = sumOf(List(1,2,3))
What's more, we can abstract over both the operation and the type of the operands:
trait Monoid[M] {
def zero: M
def add(m1: M, m2: M): M
}
trait Foldable[F[_]] {
def foldl[A, B](as: F[A], z: B, f: (B, A) => B): B
def f...
What does the “@” symbol do in Powershell?
...tialise arrays. What exactly does the @ symbol denote and where can I read more about it?
5 Answers
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Why does Hibernate require no argument constructor?
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PostgreSQL ERROR: canceling statement due to conflict with recovery
... query that causes the error works fine for 1 month but when you query for more than 1 month an error results.
8 Answers
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Why declare a struct that only contains an array in C?
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Beware of doing this with arrays, more than say 16 or 32 bytes, for functions that don't inline: it's more efficient to pass them by const-reference, unless the callee already needs a tmp copy it can destroy. If the call / return don't optimize away, a mediu...
How to check if an object is nullable?
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Emulate a do-while loop in Python?
... you return the same state, you can pick up where you left off? Give a bit more context. It seems like you might be better off using an index into the list.
– Tom
Apr 13 '09 at 6:48
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Windows batch: formatted date into variable
...variable namespace.
If you need UTC instead of local time, the command is more or less the same:
for /f %%x in ('wmic path win32_utctime get /format:list ^| findstr "="') do set %%x
set today=%Year%-%Month%-%Day%
share
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Why are there no ++ and -- operators in Python?
...ger concern being readability and predictability. Back in my C days, I saw more than enough bugs stemming from misunderstandings about the distinction between i++ and ++i...
– Charles Duffy
Jul 17 '13 at 14:54
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Why would introducing useless MOV instructions speed up a tight loop in x86_64 assembly?
...ranch prediction table isn't very large, so one table entry might refer to more than one branch. This can render some predictions useless. The problem is easily fixed if one of the conflicting branches moves to another part of the table. Almost any little change can make this happen :-)
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