# Hello World

Write a function that greets the user by name, or by saying "Hello, World!" if no name is given.

["Hello, World!"](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program) is the traditional first program for beginning programming in a new language.

**Note:** You can skip this exercise by running:

    exercism skip $LANGUAGE hello-world

## Specification

Write a `Hello World!` function that can greet someone given their name.
The function should return the appropriate greeting.

For an input of "Alice", the response should be "Hello, Alice!".

If a name is not given, the response should be "Hello, World!"

## Test-Driven Development

As programmers mature, they eventually want to test their code.

Here at Exercism we simulate [Test-Driven Development](http://en.wikipedia.org/wiki/Test-driven_development) (TDD), where you write your tests before writing any functionality. The simulation comes in the form of a pre-written test suite, which will signal that you have solved the problem.

It will also provide you with a safety net to explore other solutions without breaking the functionality.

### A typical TDD workflow on Exercism:

1. Run the test file and pick one test that's failing.
2. Write some code to fix the test you picked.
3. Re-run the tests to confirm the test is now passing.
4. Repeat from step 1.
5. Submit your solution (`exercism submit /path/to/file`)

## Instructions

Submissions are encouraged to be general, within reason. Having said that, it's also important not to over-engineer a solution.

It's important to remember that the goal is to make code as expressive and readable as we can. However, solutions to the hello-world exercise will not be reviewed by a person, but by rikki- the robot, who will offer an encouraging word.

## Setup

Follow the setup instructions for Crystal here:

http://exercism.io/languages/crystal

More help installing can be found here:

http://crystal-lang.org/docs/installation/index.html

## Making the Test Suit Pass

Execute the tests with:

```bash
$ crystal spec test_spec.cr
```

In each test suite all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by changing `pending` to `it`.

## Source

This is an exercise to introduce users to using Exercism [http://en.wikipedia.org/wiki/%22Hello,_world!%22_program](http://en.wikipedia.org/wiki/%22Hello,_world!%22_program)

## Submitting Incomplete Problems
It's possible to submit an incomplete solution so you can see how others have completed the exercise.