Today I Learned

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ruby operators <, >, === etc.

ruby -v 2.2.2

Different implementations of some of these operators can be used to do some cool things.

The #< implementation on Module for example.

> Module < BasicObject
=> true

> Object < Class
=> false

#== and #=== are implemented the same on Fixnum or BigDecimal, but on Module

> a === b

evaluates to true if b is an instance of a or a's descendants

> (1..10) === 5
=> true

> 5 === (1..10)
=> false

> 'str' === String
=> false

> String === 'str'
=> true

This is the case-equality operator and this behavior can be overridden to customize case statements. An example of overriding.

class Range
  def ===(o)
    puts 'nope sucka'

case 5
'This would normally work'
=> nope sucka
See More #ruby TILs
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