Class: Rley::Syntax::Terminal

Inherits:

GrmSymbol

• Object
• GrmSymbol
• Rley::Syntax::Terminal

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

• #initialize(aName) ⇒ Terminal constructor

  Constructor.

• #nullable? ⇒ false

  the empty string.

• #terminal? ⇒ Boolean

  Return true iff the symbol is a terminal.

Methods inherited from GrmSymbol

#generative?, #to_s

Constructor Details

#initialize(aName) ⇒ Terminal

Constructor.

Parameters:

• aName (String) —

  The name of the grammar symbol.

# File 'lib/rley/syntax/terminal.rb', line 11

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

# File 'lib/rley/syntax/terminal.rb', line 24

def nullable?() 
  false
end

#terminal? ⇒ Boolean

Return true iff the symbol is a terminal

Returns:

• (Boolean)

# File 'lib/rley/syntax/terminal.rb', line 17

def terminal?()
  return true
end