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Shorthand way for assigning a single field in a record, while copying the rest of the fields?
...o { a = 1, b = 2, c = "Hello" } -- create a Foo
> let updateFoo x = x { c = "Goodbye" } -- function to update Foos
> updateFoo foo -- update the Foo
Foo {a = 1, b = 2, c = "Goodbye" }
...
Using multiple delimiters in awk
...n the input field separator.
See another example:
$ cat file
hello#how_are_you
i#am_very#well_thank#you
This file has two fields separators, # and _. If we want to print the second field regardless of the separator being one or the other, let's make both be separators!
$ awk -F"#|_" '{print ...
Ruby - elegantly convert variable to an array if not an array already
...
@mastaBlasta Array(arg) tries to create a new array by calling to_ary, then to_a on the argument. This is documented in official ruby docs. I learned about it from Avdi's "Confident Ruby" book.
– mambo
Jul 27 '16 at 15:41
...
How does Go compile so quickly?
... whole VM, then they have to be JIT-compiled from bytecode to native code, all of which takes some time.
Speed of compilation depends on several factors.
Some languages are designed to be compiled fast. For example, Pascal was designed to be compiled using a single-pass compiler.
Compilers itself...
How to calculate moving average without keeping the count and data-total?
... This is not entirely correct. What @Muis describes is an exponentially weighted moving averge, which is sometimes appropriate but is not precisely what the OP requested. As an example, consider the behaviour you expect when most of the points are in the range 2 to 4 but one value is upward...
Can inner classes access private variables?
...ct of the parent class. You have to make the parent child relationship manually.
#include <string>
#include <iostream>
class Outer
{
class Inner
{
public:
Inner(Outer& x): parent(x) {}
void func()
{
std::string a =...
Why does `a == b or c or d` always evaluate to True?
...r is more literal minded.
if name == "Kevin" or "Jon" or "Inbar":
is logically equivalent to:
if (name == "Kevin") or ("Jon") or ("Inbar"):
Which, for user Bob, is equivalent to:
if (False) or ("Jon") or ("Inbar"):
The or operator chooses the first argument with a positive truth value:
if ("Jon")...
How would you do a “not in” query with LINQ?
... need to get a list of the items in the first list where Email does not exist in the second list. With SQL I would just use "not in", but I do not know the equivalent in LINQ. How is that done?
...
Go build: “Cannot find package” (even though GOPATH is set)
...It does not work because your foobar.go source file is not in a directory called foobar. go build and go install try to match directories, not source files.
Set $GOPATH to a valid directory, e.g. export GOPATH="$HOME/go"
Move foobar.go to $GOPATH/src/foobar/foobar.go and building should work just ...
Is a `=default` move constructor equivalent to a member-wise move constructor?
... decl-specifier-seqopt declarator virt-specifier-seqopt = default ;
is called an explicitly-defaulted definition. A function that is explicitly defaulted shall
be a special member function,
have the same declared function type (except for possibly differing ref-qualifiers and except that in the...