Class: Symbol

Inherits:
Object show all
Defined in:
lib/garcon/core_ext/symbol.rb

Overview

Author: Stefano Harding <[email protected]> License: Apache License, Version 2.0 Copyright: © 2014-2015 Stefano Harding

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.generate(key = nil) ⇒ Object

Generate a unique symbol.

Symbol.generate  #=> :"-1"

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

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



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# File 'lib/garcon/core_ext/symbol.rb', line 130

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

Instance Method Details

#/(other) ⇒ String

Join with o as a file path.

Examples:

:chef/'provider' # => 'chef/provider'
:chef/ :provider # => 'chef/provider'

Parameters:

  • other (#to_s) —

    Path component(s) to join with receiver.

Returns:

  • (String) —

    Receiver joined with other as a file path.



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# File 'lib/garcon/core_ext/symbol.rb', line 50

def /(other)
  File.join(self.to_s, other.to_s)
end

#bang? ⇒ Boolean

Symbol ends in ‘!`.

:a!.bang? #=> true
:a.bang?  #=> false

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 97

def bang?
  to_s[-1,1] == '!'
end

#call(*args, &block) ⇒ Object

Useful extension for &:symbol which makes it possible to pass arguments for method in block

['abc','','','def','ghi'].tap(&:delete.(''))
#=> ['abc','def','ghi']

[1,2,3].map(&:to_s.(2))
#=> ['1','10','11']

['abc','cdef','xy','z','wwww'].select(&:size.() == 4)
#=> ['cdef', 'wwww']

['abc','aaA','AaA','z'].count(&:upcase.().succ == 'AAB')
#=> 2

[%w{1 2 3 4 5},%w{6 7 8 9}].map(&:join.().length)
#=> [5,4]



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# File 'lib/garcon/core_ext/symbol.rb', line 164

def call(*args, &block)
  proc do |recv|
    recv.__send__(self, *args, &block)
  end
end

#clone? ⇒ Boolean

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 35

def clone? ; false ; end

#dup! ⇒ Object

Since Symbol is immutable it cannot be duplicated. For this reason #try_dup returns self.

:a.dup!  #=> :a



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# File 'lib/garcon/core_ext/symbol.rb', line 33

def dup!   ; self  ; end

#dup? ⇒ Boolean

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 34

def dup?   ; false ; end

#not? ⇒ Boolean

Does a symbol have a “not” sign?

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

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 106

def not?
  self.to_s.slice(0,1) == '~'
end

#plain? ⇒ Boolean Also known as: reader?

Symbol does not end in ‘!`, `=`, or `?`.

:a.plain?   #=> true
:a?.plain?  #=> false
:a!.plain?  #=> false
:a=.plain?  #=> false

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 61

def plain?
  c = to_s[-1,1]
  !(c == '=' || c == '?' || c == '!')
end

#query? ⇒ Boolean

Symbol ends in ‘?`.

:a?.query? #=> true
:a.query?  #=> false

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 88

def query?
  to_s[-1,1] == '?'
end

#setter? ⇒ Boolean Also known as: writer?

Symbol ends in ‘=`.

:a=.setter? #=> true
:a.setter?  #=> false

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 75

def setter?
  to_s[-1,1] == '='
end

#to_proc ⇒ Object 



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# File 'lib/garcon/core_ext/symbol.rb', line 140

def to_proc
  proc { |obj, args| obj.send(self, *args) }
  # lambda { |obj, args=nil| obj.send(self, *args) }
end

#try_dup ⇒ Object

Override this in a child if it cannot be dup’ed

Returns:



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# File 'lib/garcon/core_ext/symbol.rb', line 24

def try_dup
  self
end

#~@ ⇒ Object

Add a “not” sign to the front of a symbol.

(~:friend)  #=> :"~friend"



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# File 'lib/garcon/core_ext/symbol.rb', line 114

def ~@
  if self.to_s.slice(0,1) == '~'
    "#{self.to_s[1..-1]}".to_sym
  else
    "~#{self}".to_sym
  end
end