Class: Gloo::Verbs::Exists

Inherits:
Core::Verb show all
Defined in:
lib/gloo/verbs/exists.rb

Constant Summary collapse

KEYWORD = 
'exists?'.freeze
KEYWORD_SHORT = 
'exist'.freeze
VERB_TYPE = 
'verb'.freeze
OBJ_TYPE = 
'object'.freeze
ANY_TYPE = 
'any'.freeze
INSTANCE = 
'instance'.freeze
WRONG_NUM_ARGS_ERR = 
'Wrong number of arguments! 1 or 2 expected.'.freeze

Constants inherited from Core::Baseo

Core::Baseo::NOT_IMPLEMENTED_ERR

Instance Attribute Summary

Attributes inherited from Core::Verb

#params, #tokens

Attributes inherited from Core::Baseo

#name

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Core::Verb

#display_value, help, inherited, #initialize, #type_display

Methods inherited from Core::Baseo

#initialize, #type_display

Constructor Details

This class inherits a constructor from Gloo::Core::Verb

Class Method Details

.doc_data ⇒ Object

Get the verb's documentation data.



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# File 'lib/gloo/verbs/exists.rb', line 92

def self.doc_data
  {
    :name => KEYWORD,
    :shortcut => KEYWORD_SHORT,
    :description => 'Check to see if a verb or object type has ' \
      'been defined (or loaded). This verb can be used to check ' \
      'if a core library or extension has been loaded.',
    :syntax => [ 'exists? |any,object,verb,instance| {keyword}' ],
    :parameters => [
      "Kind of Keyword — Check for the presence of a keyword of a kind. " \
        "any (default, optional) checks for either an object or a verb; " \
        "object checks for an object matching the keyword or keyword " \
        "shortcut; verb checks for a verb matching the keyword or " \
        "keyword shortcut; instance checks to see if an object " \
        "instance exists at the pathname represented by keyword. " \
        "`exists? any markdown` is identical to `exists? markdown`.",
      '{keyword} — The verb or object keyword or keyword shortcut. ' \
        'Must be specified. For the instance option, the keyword is ' \
        'the pathname to an object instance.'
    ],
    :result => 'If the object or verb has been defined, then true, ' \
      'otherwise false. The result will be in it.',
    :errors => [
      "#{WRONG_NUM_ARGS_ERR} The kind of keyword is optional."
    ],
    :examples => <<~EXAMPLES.strip
      #
      # Example of exists? keyword.
      #
      exists [container] :

      \ton_load [script] :
      \t\texists? object markdown
      \t\tshow it # false

      \t\tload lib md
      \t\texists? object markdown
      \t\tshow it # true

      \t\texists? instance exists.on_load
      \t\tshow it # true
    EXAMPLES
  }
end

.keyword ⇒ Object

Get the Verb's keyword.



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# File 'lib/gloo/verbs/exists.rb', line 40

def self.keyword
  return KEYWORD
end

.keyword_shortcut ⇒ Object

Get the Verb's keyword shortcut.



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# File 'lib/gloo/verbs/exists.rb', line 47

def self.keyword_shortcut
  return KEYWORD_SHORT
end

Instance Method Details

#run ⇒ Object

Run the verb.



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# File 'lib/gloo/verbs/exists.rb', line 22

def run
  if @tokens.token_count == 3
    type = @tokens.second.strip.downcase
    keyword = @tokens.last
  elsif @tokens.token_count == 2
    type = ANY_TYPE
    keyword = @tokens.second
  else
    @engine.err WRONG_NUM_ARGS_ERR
    return
  end
  
  @engine.heap.it.set_to lookup_keyword(keyword, type)
end