function-overloader
v2.1.2
Published
improve overloading functions and methods in js
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FUNCTION OVERLOADER
This library/helper is solution for lack of function overloading in javascript. You can define different behaviours depending on provided arguments to the function.
install
npm install function-overloader
usage
First import/require this library
import Overload from "function-overloader";
then for function or method define rules and callbacks
const rulesForSomeFunction =
Overload
.when(<list of rules>)
.do(<callback called when above rules pass>)
.when(<list of other rules>)
.do(<callback called when above rules pass>)
// you can add as many rules as you need
Next we call rulesForSomeFunction.execute(...arguments)
inside overloaded function or method
function someOverloadedFunction() {
return rulesForSomeFunction
.execute(...arguments);
}
Right when you call someOverloadedFunction
with different arguments it will call correct callback
example
First example
Lets assume that we need function which can
- accept object with properties
name
andage
wherename
is string andage
a number. - accept two arguments where former is a string and second a number.
- accept two arguments where former is a number and second a string.
All variants should return string with format name_age
import Overload from "function-overloader";
function joinNameAndAge() {
return Overload
.when(Overload.Interface({
name: Overload.STRING,
age: Overload.NUMBER
}))
.do(objWithNameAndAge => objWithNameAndAge.name + objWithNameAndAge.age)
.when(Overload.String, Overload.NUMBER)
.do((name, age) => name + age)
.when(Overlod.Number, Overload.String)
.do((age, name) => name + age)
.execute(...arguments);
}
joinNameAndAge({
name: "Test",
age: 1
}); // Test1
joinNameAndAge("Test", 2); // Test2
joinNameAndAge(3, "Test"); // Test3
API
.when()
.when()
It is for describe when to run related do
method.
Return object with do
method
Accept multiple values that will descibe function.
There is lot of possible values, Some with additional params. All of them are available here https://github.com/uhlryk/check-complex-types
All of them are available in Overload
object. e.g. Overload.ANY()
.do()
Is accessible only from object returned from .when
method
.do()
Accept callback function which should be called if previous .when
match arguments.
.else()
.else()
Accept callback function. Will invoke it when other criteria are not met.
.elseThrow()
.elseThrow()
Throws TypeError if not any above condition met
.execute()
.execute()
accept function arguments. It is possible by passing them one by one, but preferred why is to just pass spread ...arguments
.
License
MIT