Function Argument Parser

A tool that parses function arguments into primitives, objects, arrays and functions. The Argumenter is useful for functions and constructors that have multiple parameters/arguments passed to it. Making it very useful when exposing functions as TypeScript overloads.

Usage

The Argumenter class is used within function implementations to parse input arguments.

import { Argumenter } from "@joejukan/argumenter";
export function someFunc(...args){
    let a = new Argumenter(args);
}

The Argumenter class provides 5 getter properties that are used to extract values from the parameters that are passed into the function.

|Property |Description | |------------------|-------------------------------------------------------------------| |string |Retrieves a string value from the available function arguments | |number |Retrieves a number value from the available function arguments | |boolean |Retrieves a boolean value from the available function arguments | |object |Retrieves an object from the available function arguments | |array |Retrieves an array from the available function arguments | |function |Retrieves a callback from the available function arguments |

import { Argumenter } from "@joejukan/argumenter";
function handleArgs(...args){
    let a = new Argumenter(args);
    console.log(`string: ${a.string}, number: ${a.number}, boolean: ${a.boolean}`);
}

handleArgs('Hello World!', 3320, true);
// string: Hello World!, number: 3320, boolean: true

handleArgs(3320, true, 'Hello World!');
// string: Hello World!, number: 3320, boolean: true

Note: that it does not matter the order of the parameters. The Argumenter will successfully parse the arguments according to their types.

The Argumenter class provides 1 function instance that isolates objects of a specific class in the input arguments.

import { Argumenter } from "@joejukan/argumenter";
class Doctor {
}

class Lawyer {
}

class Engineer {
}

class Pediatrician extends Doctor {
}

function occupation(...args){
    let a = new Argumenter(args);
    let lawyer = a.instance(Lawyer);
    let doctor = a.instance(Doctor);

    if(lawyer){
        console.log('Legal Advice');
    }
    if(doctor){
        console.log('Medical Advice');
    }
}

occupation(new Doctor());
// Medical Advice

occupation(new Lawyer());
// Legal Advice

occupation(new Engineer());
//

occupation(new Pediatrician());
// Medical Advice

Below is an example on how to utilize the Argumenter to support an overloaded function in typescript.

import { Argumenter } from "@joejukan/argumenter";

hello();
hello(name: string);
hello(age: number);
hello(name: string, age: number);
hello(age: number, name: string);
hello(...args){
    var a = new Argumenter(args);
    var name = a.string;
    var age = a.number;

    if(name && age){
        return `Hello ${name}, your are ${age} years old`;
    }

    else if(name){
        return `Hello ${name}`;
    }

    else if(age){
        return `Hello, you are ${age} years old`;
    }

    return "Hello, I do not know your age.";
}

Note: that all types of argumentation permutations are supported in typescript overloading.

The Argumenter class can handle multiple parameters of the same type:

import { Argumenter } from "@joejukan/argumenter";

interface Person{
    firstName: string;
    lastName: string;
}

function createPerson(firstName: string, lastName: string): Person
function createPerson(...args): Person{
    var a = new Argumenter(args);
    let first = a.string;
    let last = a.string;

    return <Person>{firstName: first, lastName: last}
}

let person = createPerson('Jane', 'Doe');
console.log(person);
// { firstName: 'Jane', lastName: 'Doe'}

Note: The property getter (string in this case) was used to retrieve both string parameter values one at a time. Therfore, it is important to store the results of the getter properties to separate variables. A argument parameter value will no longer be accessible from the Argumenter object once it is exposed by the getter property.

Installation

Do the following steps to install argumenter:

npm install @joejukan/argumenter

Authors

01) Joseph Eniojukan - joejukan

ChangeLog

CHANGELOG.md file for details

License

This project is licensed under the ISC License - see the LICENSE.md file for details

Copyright 2018 Joseph Eniojukan

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.