Sha256: 9f3f943d89bebe7c68a279b2a6eebbfa1dfcff7611da63ff34cd8aa145ffb2b7
Contents?: true
Size: 1.04 KB
Versions: 17
Compression:
Stored size: 1.04 KB
Contents
# frozen_string_literal: true
require_relative 'grm_symbol'
module Dendroid
module Syntax
# A non-terminal symbol (sometimes called a syntactic variable) represents
# a composition of terminal or non-terminal symbols
class NonTerminal < GrmSymbol
# @return [Boolean] true if symbol can derive the null token
attr_accessor :nullable
# @return [Boolean] true iff the symbol always matches a non-empty
# sequence of terminal symbols
attr_accessor :productive
# Predicate method to check whether the symbol is a terminal symbol.
# @return [FalseClass]
def terminal?
false
end
# Predicate method to check whether the symbol can derive (match)
# the null token.
# @return [Boolean]
def nullable?
@nullable
end
# Predicate method to check whether the symbol always matches
# a non-empty sequence of terminal symbols.
# @return [Boolean]
def productive?
@productive
end
end # class
end # module
end # module
Version data entries
17 entries across 17 versions & 1 rubygems