---
title:  Ruby
blurb:  As the language that powers <em>Middlemac</em>, it’s worth taking a
        short look at the Ruby language.
layout: template-logo-medium
---
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<%= md_images %>

<%= current_page.data.title %>
==============================

<%= current_page.data.blurb %>

[Ruby](https://www.ruby-lang.org/en/) is the language that _Middlemac_,
_Middleman_, and many of the others tools are written with. You do not have to
learn Ruby to take advantage of _Middlemac_, although some ability to work with
it will be invaluable to you.

Ruby may surprise you
---------------------

If you’re a software developer, then it’s highly likely that you will be able to
read most Ruby code immediately. Coming from an Objective-C or Swift background,
these are a few things that may surprise you.

### Symbols
Ruby has a type of identifier called a `symbol`. They are used quite extensively
and look like `:this_symbol`. As identifiers and not variables, you can’t assign
values to them. Their value is themselves, though they have useful string
representations (`:this_symbol.to_s`). You can even get the symbol
representation of `'this_string'.to_sym`. Because they're unique, they make
excellent array/hash keys and excellent, guaranteed unique values.

### Everything is an object
Everything is an object, including what are fundamental datatypes in other
languages. Need to convert the integer `i` to a float? It’s as easy as
`i.to_f`.
              
### Everything has a return value
In Ruby you don’t require `return value`, or `result := value`, or
`function_name = value`. Just `value`, alone, will return its value. Even `if`
statements return values:

~~~ ruby
result = if answer == 'yes'
            "The answer as affirmative."
         else
            "The answer was something else."
         end
~~~

This example assigns the appropriate string to the variable `result`.


Just enough Ruby
----------------
To work effectively with _Middlemac_ you’ll only have to learn enough Ruby to
do a few simple things:

- Set variables in the `config.rb` file.
- Use a few helper functions from within files, e.g., `partial 'my_file'`.
- Use conditionals, if you want them. You know: simply `if/else/end`, or even
  `unless/else/end`.

Examples of these last two points can be seen when we take a look at
[File Types][filetypes_skill].