Class: Symbol

Methods

chomp generate lchomp not? plain? query? re_s setter? succ to_proc variablize ~

Public Class methods

generate(key=nil)

Generate a unique symbol.

  Symbol.generate => :-1

If key is given the new symbol will be prefixed with it.

  Symbol.generate(:foo) => :foo-1

  TODO: Is the generated symbol format acceptable?

CREDIT: Trans

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# File lib/core/facets/symbol/generate.rb, line 15
  def self.generate(key=nil)
    key = key.to_sym if key
    @symbol_generate_counter ||= {}
    @symbol_generate_counter[key] ||= 0
    num = @symbol_generate_counter[key] += 1
    ("#{key}-%X" % num).to_sym
  end

Public Instance methods

chomp(seperator)

Just like String#chomp.

  :ab.chomp(:b)  #=> :a

CREDIT: Trans

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# File lib/core/facets/symbol/chomp.rb, line 9
  def chomp(seperator)
    to_s.chomp(seperator.to_s).to_sym
  end

lchomp(seperator)

Just like String#lchomp.

  :ab.lchomp(:a)  #=> :b

CREDIT: Trans

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# File lib/core/facets/symbol/chomp.rb, line 19
  def lchomp(seperator)
    to_s.reverse.chomp(seperator.to_s).reverse.to_sym
  end

not?()

Does a symbol have a "not" sign?

  "friend".to_sym.not?   #=> false
  "~friend".to_sym.not?  #=> true

CREDIT: Trans

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# File lib/core/facets/symbol/not.rb, line 10
  def not?
    self.to_s.slice(0,1) == '~'
  end

plain?()

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# File lib/core/facets/symbol/plain.rb, line 3
  def plain?
    c = to_s[-1,1]
    !(c == '=' || c == '?')
  end

query?()

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# File lib/core/facets/symbol/plain.rb, line 12
  def query?
    to_s[-1,1] == '?'
  end

re_s()

Convert symbol to string, apply string method and convert back to symbol via a fluent interface.

  :HELLO.re_s.downcase

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# File lib/core/facets/symbol/re_s.rb, line 11
  def re_s
    @re_s ||= Functor.new do |op, *a|
      to_s.send(op, *a).to_sym
    end
  end

setter?()

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# File lib/core/facets/symbol/plain.rb, line 8
  def setter?
    to_s[-1,1] == '='
  end

succ()

Successor method for symobol. This simply converts the symbol to a string uses String#succ and then converts it back to a symbol.

  :a.succ => :b

TODO: Make this work more like a simple character dial?

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# File lib/core/facets/symbol/succ.rb, line 13
    def succ
      self.to_s.succ.intern
    end

to_proc()

Turn a symbol into a proc calling the method to which it refers.

  up = :upcase.to_proc
  up.call("hello")  #=> HELLO

More useful is the fact that this allows & to be used to coerce Symbol into Proc.

  %w{foo bar qux}.map(&:upcase)   #=> ["FOO","BAR","QUX"]
  [1, 2, 3].inject(&:+)           #=> 6

And other conveniences such as:

  %{john terry fiona}.map(&:capitalize)   # -> %{John Terry Fiona}
  sum = numbers.inject(&:+)

TODO: This will be deprecated as of Ruby 1.9, since it will become standard Ruby.

CREDIT: Florian Gross (orignal), Nobuhiro Imai (current)

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# File lib/core/facets/symbol/to_proc.rb, line 26
    def to_proc
      Proc.new{|*args| args.shift.__send__(self, *args)}
    end

variablize()

Prepend an "@" to the beginning of a symbol to make a instance variable name. This also replaces non-valid characters with underscores.

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# File lib/core/facets/symbol/variablize.rb, line 7
  def variablize
    "@#{self}".gsub(/\W/, '_').to_sym
  end

~()

Add a "not" sign to the front of a symbol.

  ~:friend    #=> :"~friend"

CREDIT: Trans

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# File lib/core/facets/symbol/not.rb, line 20
  def ~@
    if self.to_s.slice(0,1) == '~'
      "#{self.to_s[1..-1]}".to_sym
    else
      "~#{self}".to_sym
    end
  end