argx
Parse function arguments. Useful to implement variadic functions.
Installation
npm install argx --save
Usage
Pass the arguments
object to .argx()
inside your function.
/** * This is an example to declare an variadic functions. */'use strict' const argx = { let args = callback = args || {} // Consume last argument if it's a function. options = args || {} // Consume last argument if it's an object. values = args // Get remaining arguments as array. /* ... */}
API Guide
API guide for Argx instance, which is returned by argx(arguments)
.
Signature | Description | Example |
---|---|---|
.pop() | Pop an argument value from last. | args.pop() |
.pop(count) | Pop multiple values from last. Orders are preserved. | args.pop(1) |
.pop(type) | Pop only if the last value conform the type. | args.pop("number") args.pop("number|string") args.pop(CustomObj) |
.pop(count, type) | Pop values while conforming the type. | args.pop(2, "number") args.pop(1, CustomObj) |
.shift() | Shift an argument value from top. | args.shift() |
.shift(count) | Shift multiple values from top. | args.shift(2) |
.shift(type) | Shift only if the top value conform the type. | args.shift("string") args.pop("object|string") args.shift(CustomObj) |
.shift(count, type) | Shift values while conforming the type. | args.shift(2, "string") args.shift(4, CustomObj) |
.remain() | Shift all remained values. Always returns an array. | args.remain() |
Tips
Detecting Custom Types.
Type which .pop()
/.shift()
accept is string, a custom object or a custom constructor.
{/*...*/};args; // Pop only if the last argument is instantiate by `new MyConstructor()` var MyObj = /*...*/;args; // Pop only if the last argument is create by `Object.create(MyObj)`
Specify Multiple Types
There are two ways to specify 'or' condition for types.
- Passing string joined by "|" (eg:
args.pop('string|number');
) - Passing array as type (eg:
args.pop(['string', MyCustomObj]);
)
Want Array Always
Note that .pop()
/.shift()
methods returns values as array only when multiple entries hit.
If you want to make sure to keep values as array, use [].concat()
.
var args = ;var values = ; // Always array.
License
This software is released under the MIT License.