Class: Parslet::Atoms::Entity

Inherits:
Base
  • Object
show all
Defined in:
lib/parslet/atoms/entity.rb,
lib/parslet/atoms/visitor.rb

Overview

This wraps pieces of parslet definition and gives them a name. The wrapped piece is lazily evaluated and cached. This has two purposes:

  • Avoid infinite recursion during evaluation of the definition

  • Be able to print things by their name, not by their sometimes complicated content.

You don’t normally use this directly, instead you should generated it by using the structuring method Parslet.rule.

Direct Known Subclasses

Rule

Constant Summary

Constants included from Precedence

Precedence::ALTERNATE, Precedence::BASE, Precedence::LOOKAHEAD, Precedence::OUTER, Precedence::REPETITION, Precedence::SEQUENCE

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#apply, #inspect, #parse, #parse_with_debug, precedence, #setup_and_apply, #to_s

Methods included from CanFlatten

#flatten, #flatten_repetition, #flatten_sequence, #foldl, #merge_fold, #warn_about_duplicate_keys

Methods included from DSL

#>>, #absent?, #as, #maybe, #present?, #repeat, #|

Constructor Details

#initialize(name, &block) ⇒ Entity

Returns a new instance of Entity.



13
14
15
16
17
18
 
# File 'lib/parslet/atoms/entity.rb', line 13

def initialize(name, &block)
  super()
  
  @name = name
  @block = block
end

Instance Attribute Details

#block ⇒ Object (readonly)

Returns the value of attribute block.



12
13
14
 
# File 'lib/parslet/atoms/entity.rb', line 12

def block
  @block
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



12
13
14
 
# File 'lib/parslet/atoms/entity.rb', line 12

def name
  @name
end

Instance Method Details

#accept(visitor) ⇒ Object

Call back visitors #visit_entity method. See parslet/export for an example.



24
25
26
 
# File 'lib/parslet/atoms/visitor.rb', line 24

def accept(visitor)
  visitor.visit_entity(name, block)
end

#parslet ⇒ Object 



24
25
26
27
28
 
# File 'lib/parslet/atoms/entity.rb', line 24

def parslet
  @parslet ||= @block.call.tap { |p| 
    raise_not_implemented unless p
  }
end

#to_s_inner(prec) ⇒ Object 



30
31
32
 
# File 'lib/parslet/atoms/entity.rb', line 30

def to_s_inner(prec)
  name.to_s.upcase
end

#try(source, context) ⇒ Object 



20
21
22
 
# File 'lib/parslet/atoms/entity.rb', line 20

def try(source, context)
  parslet.apply(source, context)
end