use_case.md

Run Irb

Use the run_irb feature to execute markdown-embedded Ruby snippets in the Ruby interactive shell, irb.

This allows you to interleave Ruby snippets with any markdown (usually explanatory text, but actually anything).

In the example template below, snippets of Ruby are interleaved with other markdown elements.

Each Ruby snippet that's to be executed in irb is bracketed by pragmas ```#run_irb and ```.

In the example, each snippet has some Ruby code that shows values using method p.

# About Hashes

Create a hash:

```#run_irb
h = {}
p h.class
p h
```

Initialize a hash:

```#run_irb
h = {:a => 0, :b => 1}
p h
```

Change a value:

```#run_irb
h[:b] = 2
p h
```

Add a new entry:

```#run_irb
h[:c] = 2
p h
```

Delete an entry:

```#run_irb
h.delete(:a)
p h
```

Run Irb Via markdown_helper

CLI

markdown_helper run_irb --pristine template.md markdown.md

(Option --pristine suppresses comment insertion.)

API

run_irb.rb:

require 'markdown_helper'

# Option :pristine suppresses comment insertion.
markdown_helper = MarkdownHelper.new(:pristine => true)
markdown_helper.run_irb('template.md', 'markdown.md')

The resulting markdown (raw) shows the output from irb for each snippet:

# About Hashes

Create a hash:

```ruby
h = {}
p h.class
Hash
p h
{}
```

Initialize a hash:

```ruby
h = {:a => 0, :b => 1}
p h
{:a=>0, :b=>1}
```

Change a value:

```ruby
h[:b] = 2
p h
{:a=>0, :b=>2}
```

Add a new entry:

```ruby
h[:c] = 2
p h
{:a=>0, :b=>2, :c=>2}
```

Delete an entry:

```ruby
h.delete(:a)
p h
{:b=>2, :c=>2}
```

Resulting markdown (rendered):

---

About Hashes

Create a hash:

h = {}
p h.class
Hash
p h
{}

Initialize a hash:

h = {:a => 0, :b => 1}
p h
{:a=>0, :b=>1}

Change a value:

h[:b] = 2
p h
{:a=>0, :b=>2}

Add a new entry:

h[:c] = 2
p h
{:a=>0, :b=>2, :c=>2}

Delete an entry:

h.delete(:a)
p h
{:b=>2, :c=>2}

---