Composite Function
A composite function is created by combining two functions, equivalent to
f(g(x)). Here, x is the input argument(s), which can be one
or more. The core idea of a composite function is to use the output of one function as
the input to the other, creating a new, combined function. This can enhance code
readability, make it easier to maintain, and simplify complex logic.
In DolphinDB, composite functions can be created using the compose function. The
compose(first, second) function takes two functions as arguments.
It first calls the first function with the given parameters, then passes the
result as the input to the second function, and returns the final result of
second(first(...)). The new function returned by
compose has the same parameters as the first function.
doubleValue and
increment. We can combine these two functions into a new composite
function that first applies doubleValue, then uses the result as input
for increment, and finally returns the
outcome.// Define two simple functions
doubleValue = x -> x * 2
increment = x -> x + 1
// Create a composite function
composedFunc = compose(doubleValue, increment)
composedFunc([3, 4, 5]) // Output: [7, 9, 11]