getting serious

1 files changed, 132 insertions, 0 deletions

diff --git a/grammar.rb b/grammar.rb
new file mode 100644
index 0000000..f703e7e
--- /dev/null
+++ b/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='', span=nil
+    @lhs = lhs
+    @rhs = rhs
+    @e = e
+    @lhs.span = span if span
+  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, tail_spans=nil
+    nt_dict = {}
+    tail_spans.split(';').each { |i|
+      symbol, idx, span = i.split('|||')
+      nt_dict[idx.to_i] = span.gsub('(','').gsub(')','').split(',').map{|i|i.to_i}
+    }
+    _ = splitpipe s, 3
+    @lhs = NT.new _[0].strip.gsub!(/(\[|\])/, "")
+    q = 0
+    _[1].split.each { |x|
+      x.strip!
+      if x[0]=='[' && x[x.size-1] == ']'
+        @rhs << NT.new(x.gsub!(/(\[|\])/, "").split(',')[0])
+        @rhs.last.span.left = nt_dict[q][0]
+        @rhs.last.span.right = nt_dict[q][1]
+        q += 1
+      else
+        @rhs << T.new(x)
+      end
+    }
+    @e = _[2]
+  end
+
+  def self.from_s s, tail_spans=nil
+    r = self.new
+    r.from_s s, tail_spans
+    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
+