Class: Rley::Syntax::Terminal

Inherits:
GrmSymbol show all
Defined in:
lib/rley/syntax/terminal.rb

Overview

A terminal symbol represents a class of words in the language defined the grammar.

Direct Known Subclasses

Literal, VerbatimSymbol

Instance Attribute Summary

Attributes inherited from GrmSymbol

#generative, #name

Instance Method Summary collapse

Methods inherited from GrmSymbol

#generative?

Constructor Details

#initialize(aName) ⇒ Terminal

Constructor.

Parameters:

  • aName (String) —

    The name of the grammar symbol.



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# File 'lib/rley/syntax/terminal.rb', line 12

def initialize(aName)
  super(aName)
  self.generative = true
end

Instance Method Details

#nullable? ⇒ false

the empty string. As terminal symbol corresponds to a input token it is by definition non-nullable.

Returns:

  • (false) —

    Return true if the symbol derives



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# File 'lib/rley/syntax/terminal.rb', line 25

def nullable?
  false
end

#terminal? ⇒ Boolean

Return true iff the symbol is a terminal

Returns:

  • (Boolean) 


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# File 'lib/rley/syntax/terminal.rb', line 18

def terminal?
  return true
end

#to_s ⇒ Object 



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# File 'lib/rley/syntax/terminal.rb', line 29

def to_s
  name
end