https://github.com/dwbutler/numeric

Adds numeric checking to Ruby
https://github.com/dwbutler/numeric

Last synced: about 1 month ago
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Adds numeric checking to Ruby

• Host: GitHub
• URL: https://github.com/dwbutler/numeric
• Owner: dwbutler
• License: mit
• Created: 2013-09-11T18:27:47.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-12-26T04:35:17.000Z (almost 11 years ago)
• Last Synced: 2024-03-14T23:21:01.957Z (9 months ago)
• Language: Ruby
• Homepage:
• Size: 121 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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README

        
# Numeric [![Build Status](https://travis-ci.org/dwbutler/numeric.png)](https://travis-ci.org/dwbutler/numeric)

Checking if a given value is "numeric" is a common problem. How can we do in this Ruby?

There are many problematic ways, such as converting to an integer or float or using a regex:

```ruby

"String".to_i

# => 0

nil.to_f

# => 0.0

:'0'.to_i

# NoMethodError: undefined method `to_i' for :"0":Symbol

"1e5" =~ /^\d*$/

 => nil

```

This gem defines a simple (and correct) `#numeric?` method on all Ruby objects.

The rules are simple:

 * All descendants of `Numeric` are numeric.

 * All strings or symbols that can be converted with `Complex()` are numeric.

 * All other objects are not numeric.

If you want to get more specific, the following methods are also defined:

 * `#integer?`

 * `#float?`

 * `#decimal?`

 * `#rational?`

 * `#complex?`

Note that for these more specific methods, a string that can be converted to

a `Float` (such as '1') will return `true` for `#float?`. An instance of a different

Numeric class (such as 1, Integer) will return `false` for `#float?`.

## Compatibility

The gem is tested to work in MRI Ruby 1.9 - 2.0, and JRuby (1.9 mode).

All other Rubies are too lax in what their `Numeric` classes accept, which prevents

this gem from working completely.

MRI 2.0.0's `BigDecimal` class is also too lax in what it accepts, so `'a'.decimal?` will

unfortunately return `true`.

## Installation

Add this line to your application's Gemfile:

    gem 'numeric'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install numeric

## Usage

```ruby

require 'numeric'

3.numeric?

# => true

'1'.numeric?

# => true

'3e10'.numeric?

# => true

:'0'.numeric?

# => true

'abc123'.numeric?

# => false

{}.numeric?

# => false

```

## Contributing

1. Fork it

2. Create your feature branch (`git checkout -b my-new-feature`)

3. Commit your changes (`git commit -am 'Add some feature'`)

4. Push to the branch (`git push origin my-new-feature`)

5. Create new Pull Request