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require 'nlp_ruby'
class T
attr_accessor :word
def initialize word
@word = word
end
def to_s
"T<#{@word}>"
end
end
class NT
attr_accessor :symbol, :index
def initialize symbol, index=0
@symbol = symbol
@index = index
end
def to_s
"NT<#{@symbol},#{@index}>"
end
end
class Rule
attr_accessor :lhs, :rhs
def initialize lhs=nil, rhs=[]
@lhs = lhs
@rhs = rhs
end
def to_s
"#{lhs} -> #{rhs.map{ |i| i.to_s }.join ' '} [arity=#{arity}]"
end
def arity
rhs.reject { |i| i.class==T }.size
end
def from_s s
_ = splitpipe s, 3
@lhs = NT.new _[0].strip.gsub!(/(\[|\])/, "")
_[1].split.each { |i|
i.strip!
if i[0]=='[' && i[i.size-1] == ']'
@rhs << NT.new(i.gsub!(/(\[|\])/, "").split(',')[0])
else
@rhs << T.new(i)
end
}
end
def self.from_s s
r = self.new
r.from_s s
r
end
end
class Grammar
attr_accessor :rules
def initialize fn
@rules = []
ReadFile.readlines_strip(fn).each_with_index { |s,j|
#STDERR.write '.'
#puts "\n" if j%100==0&&j>0
@rules << Rule.from_s(s)
}
end
def to_s
s = ''
@rules.each { |r| s += r.to_s+"\n" }
s
end
def add_glue_rules
@rules.map { |r| r.lhs.symbol }.reject { |s| s=='S' }.uniq.each { |s|
@rules << Rule.new(NT.new('S'), [NT.new(s)])
@rules << Rule.new(NT.new('S'), [NT.new('S'), NT.new('X')])
}
end
def add_pass_through_rules input
input.each { |terminal|
@rules << Rule.new(NT.new('X'), [T.new(terminal.word)])
}
end
end
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