It’s useful as an argument to higher order functions (functions which take functions as arguments), where you want some particular value left unchanged. Example 1: Leave a value alone if it is in a Just, otherwise, return a default of 7. Prelude Data.Maybe> :t maybe maybe :: b -> (a -> b) -> Maybe a … Read more
Here is a list of red-flags (in no particular order) that could indicate that a function is too long: Deeply nested control structures: e.g. for-loops 3 levels deep or even just 2 levels deep with nested if-statements that have complex conditions. Too many state-defining parameters: By state-defining parameter, I mean a function parameter that guarantees … Read more
Identifier expected Your code would be correct in a Pascal, but it does not compile in Pascal Script. In Pascal, when you want to assign a return value of a function, you either assign the value to a “variable” with a name of the function or to Result variable. So this is correct: function GetRoot: … Read more
You can’t access Function2 inside of it if it is in the line where you declare it. The reason is that you’re not referring to a function but to a variable (whose type is a function) and it will be accessible only after the declaration. Quoting from Spec: Declarations and scope: The scope of a … Read more
Actually, doing arbitrary arity with type classes turns out to be incredibly easy: module Pred where class Predicate a where complement :: a -> a instance Predicate Bool where complement = not instance (Predicate b) => Predicate (a -> b) where complement f = \a -> complement (f a) — if you want to be … Read more
I prefer using structures for my options. This gives you an easy way to store the options and an easy way to define them. Also, the whole thing becomes rather compact. function example(varargin) %# define defaults at the beginning of the code so that you do not need to %# scroll way down in case … Read more
In CMake, functions have their own scope, and by default, all modification of variables are local, unless you pass CACHE or PARENT_SCOPE as parameter to set. Inside a function, if you want to modify a variable in the scope of the caller, you should use: set(${dst_list} <something> PARENT_SCOPE) See documentation: A function opens a new … Read more
You have probably already noticed that the order of loading the packages makes a difference, i.e. the package that gets loaded last will mask the functions in packages loaded earlier. To specify the package that you want to use, the syntax is: chron::is.weekend() tseries::is.weekend() In other words, use packagename::functionname() In addition, if you know that … Read more
As far as I understand at the moment: functions are “global”, which means I do not have to import a package to use functions, they are always there. Methods are bound to packages. Is this correct? No, that’s not correct. There are just a couple of functions from the builtin package which are always available. … Read more
Do you want to do this without changing the code that you want to measure timings for? If you don’t mind changing the code, then you could do something like this: def time[R](block: => R): R = { val t0 = System.nanoTime() val result = block // call-by-name val t1 = System.nanoTime() println(“Elapsed time: ” … Read more