Module: Enumerable

Defined in:
lib/qualitysmith_extensions/symbol/match.rb,
lib/qualitysmith_extensions/enumerable/enum.rb

Instance Method Summary collapse

Instance Method Details

#enum(iterator = :each) ⇒ Object

The core Enumerable module provides the following enumerator methods;

  • enum_cons()

  • enum_slice()

  • enum_with_index()

but for some reason they didn’t provide a generic enum() method for the cases they didn’t think of!

enum lets you turn any iterator into a general-purpose Enumerator, which, according to the RDocs, is “A class which provides a method ‘each’ to be used as an Enumerable object.”

This lets you turn any ‘each'-type iterator (each_byte, each_line, …) into a ’map‘-type iterator (one that returns a collection), or into an array, etc.

So if an object responds to :each_line but not to :map_lines or :lines, you could just do:

object.enum(:each_line).map { block }
object.enum(:each_line).min
object.enum(:each_line).grep /pattern/
lines = object.enum(:each_line).to_a

If no iterator is specified, :each is assumed:

object.enum.map { block }

More examples:

Dir.new('.').enum.to_a
#=> ['file1', 'file2']

"abc".enum(:each_byte).map{|byte| byte.chr.upcase}
#=> ["A", "B", "C"]



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# File 'lib/qualitysmith_extensions/enumerable/enum.rb', line 39

def enum(iterator = :each)
  Enumerable::Enumerator.new(self, iterator)
end

#grep_with_regexp_support_for_symbols(pattern, &block) ⇒ Object 



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# File 'lib/qualitysmith_extensions/symbol/match.rb', line 88

def grep_with_regexp_support_for_symbols(pattern, &block)
  map { |element|
    element.is_a?(Symbol) ? element.to_s : element
  }.grep_without_regexp_support_for_symbols(pattern, &block)
end