either-or

TL;DR

Write code as branches to be enumerated.

var EitherOr = require('either-or');

EitherOr.runAll(function(eo) {
  console.log("Hello");
  eo.either(function() {
    console.log("Doctor Jekill");
  }).or(function() {
    console.log("Mister Hide");
  });
  console.log("Have a nice day");
});

Prints:

Hello
Doctor Jekill
Have a nice day
Hello
Mister Hide
Have a nice day

Install

Install the package:

npm install either-or

Use it:

var EitherOr = require('either-or');

Use

Either... or...

Multiple branches

Try two branches:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  eo.either(function() {
    console.log("Doctor Jekill");
  }).or(function() {
    console.log("Mister Hide");
  });
  console.log("Have a nice day");
});

Prints:

Hello
Doctor Jekill
Have a nice day
Hello
Mister Hide
Have a nice day

You can add as many or as needed:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  eo.either(function() {
    console.log("Doctor Jekill");
  }).or(function() {
    console.log("Mister Hide");
  }).or(function() {
    console.log("Mister Utterson");
  });
  console.log("Have a nice day");
});

Conditions

You can use conditions to skip branches:

var happyEnding = true;
EitherOr.runAll(function(eo) {
  console.log("Hello");
  eo.either(function() {
    console.log("Doctor Jekill");
  }).or({if: !happyEnding}, function() {
    console.log("Mister Hide");
  });
  console.log("Have a nice day");
});

Prints:

Hello
Doctor Jekill
Have a nice day

Choose

Enumerate arrays

You can also enumerate the elements of an array:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  var name = eo.choose(["Doctor Jekill", "Mister Hide"]);
  console.log(name);
  console.log("Have a nice day");
});

Prints:

Hello
Doctor Jekill
Have a nice day
Hello
Mister Hide
Have a nice day

Conditions

You can filter the elements:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  var name = eo.choose(["Doctor Jekill", "Mister Hide"], {
    with: function(e) { return e.startsWith("Doctor"); }
  });
  console.log(name);
  console.log("Have a nice day");
});

Prints:

Hello
Doctor Jekill
Have a nice day

Combine

You can also combine these constructs at will.

Nest either/or:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  eo.either(function() {
    console.log("Doctor Jekill");
  }).or(function() {
    console.log("Mister Hide");
    eo.either(function() {
      console.log("O mysterious character");
    }).or(function() {
      console.log("O dangerous man");
    });
  });
  console.log("Have a nice day");
  console.log("");
});

Prints:

Hello
Doctor Jekill
Have a nice day

Hello
Mister Hide
O mysterious character
Have a nice day

Hello
Mister Hide
O dangerous man
Have a nice day

Either/or in series:

EitherOr.runAll(function(eo) {
  console.log("Hello");

  eo.either(function() {
    console.log("Doctor Jekill");
  }).or(function() {
    console.log("Mister Hide");
  });

  eo.either(function() {
    console.log("Have a nice day");
  }).or(function() {
    console.log("I wish we never met");
  });

  console.log("");
});

Prints:

Hello
Doctor Jekill
Have a nice day

Hello
Doctor Jekill
I wish we never met

Hello
Mister Hide
Have a nice day

Hello
Mister Hide
I wish we never met

Either/or and choose:

EitherOr.runAll(function(eo) {
  console.log("Hello");
  var name = eo.choose(["Doctor Jekill", "Mister Hide"]);

  eo.either(function() {
    console.log(name);
  }).or(function() {
    console.log(name.toUpperCase());
  });
  console.log("Have a nice day");
  console.log("");
});

Prints:

Hello
Doctor Jekill
Have a nice day

Hello
DOCTOR JEKILL
Have a nice day

Hello
Mister Hide
Have a nice day

Hello
MISTER HIDE
Have a nice day

Conditions can help combine more complex data:

EitherOr.runAll(function(eo) {
  console.log("Hello");

  var name = eo.choose(["Doctor Jekill", "Mister Hide"]);

  eo.either(function() {
    console.log("Nice to meet you");
  }).or({if: (name.starsWith('Doctor'))}, function() {
    console.log("Could you examine my cough?");
  });

  console.log("Have a nice day");
  console.log("");
});

Prints:

Hello
Doctor Jekill
Nice to meet you
Have a nice day

Hello
Doctor Jekill
Could you examine my cough?
Have a nice day

Hello
Mister Hide
Nice to meet you
Have a nice day

Contribute

Pull requests are very welcome. If you add or change some code, by all means, write some tests.

If you feel your PR is quite obvious (typo, bug...), you can submit it directly. If it is a new feature or a change it the package behavior, first post an issue to discuss it.