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-rw-r--r--lib/nlp_ruby/grammar.rb122
1 files changed, 122 insertions, 0 deletions
diff --git a/lib/nlp_ruby/grammar.rb b/lib/nlp_ruby/grammar.rb
new file mode 100644
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+++ b/lib/nlp_ruby/grammar.rb
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+module Grammar
+
+class T
+ attr_accessor :word
+
+ def initialize word
+ @word = word
+ end
+
+ def to_s
+ "T<#{@word}>"
+ end
+end
+
+class NT
+ attr_accessor :symbol, :index, :span
+
+ def initialize symbol, index=0
+ @symbol = symbol
+ @index = index
+ @span = Span.new
+ end
+
+ def to_s
+ "NT(#{@span.left},#{@span.right})<#{@symbol},#{@index}>"
+ end
+end
+
+class Rule
+ attr_accessor :lhs, :rhs, :e
+
+ def initialize lhs=nil, rhs=[], e=''
+ @lhs = lhs
+ @rhs = rhs
+ @e = e
+ end
+
+ def to_s
+ "#{lhs} -> #{rhs.map{ |i| i.to_s }.join ' '} [arity=#{arity}] ||| #{@e}"
+ end
+
+ def arity
+ rhs.select { |i| i.class == NT }.size
+ end
+
+ def from_s s
+ _ = splitpipe s, 3
+ @lhs = NT.new _[0].strip.gsub!(/(\[|\])/, "")
+ _[1].split.each { |x|
+ x.strip!
+ if x[0]=='[' && x[x.size-1] == ']'
+ @rhs << NT.new(x.gsub!(/(\[|\])/, "").split(',')[0])
+ else
+ @rhs << T.new(x)
+ end
+ }
+ @e = _[2]
+ end
+
+ def self.from_s s
+ r = self.new
+ r.from_s s
+ return r
+ end
+end
+
+class Span
+ attr_accessor :left, :right
+
+ def initialize left=nil, right=nil
+ @left = left
+ @right = right
+ end
+end
+
+class Grammar
+ attr_accessor :rules, :startn, :startt, :flat
+
+ def initialize fn
+ @rules = []; @startn = []; @startt = [] ;@flat = []
+ ReadFile.readlines_strip(fn).each_with_index { |s,i|
+ STDERR.write '.'; STDERR.write " #{i+1}\n" if (i+1)%80==0
+ @rules << Rule.from_s(s)
+ if @rules.last.rhs.first.class == NT
+ @startn << @rules.last
+ else
+ if rules.last.arity == 0
+ @flat << @rules.last
+ else
+ @startt << @rules.last
+ end
+ end
+ }
+ STDERR.write "\n"
+ end
+
+ def to_s
+ s = ''
+ @rules.each { |r| s += r.to_s+"\n" }
+ return s
+ end
+
+ def add_glue_rules
+ @rules.map { |r| r.lhs.symbol }.select { |s| s != 'S' }.uniq.each { |symbol|
+ @rules << Rule.new(NT.new('S'), [NT.new(symbol)])
+ @startn << @rules.last
+ @rules << Rule.new(NT.new('S'), [NT.new('S'), NT.new('X')])
+ @startn << @rules.last
+ }
+ end
+
+ def add_pass_through_rules s
+ s.each { |word|
+ @rules << Rule.new(NT.new('X'), [T.new(word)])
+ @flat << @rules.last
+ }
+ end
+end
+
+
+end # module
+