spring cleaning

1 files changed, 137 insertions, 0 deletions

diff --git a/prototype/grammar.rb b/prototype/grammar.rb
new file mode 100644
index 0000000..42ffbc0
--- /dev/null
+++ b/prototype/grammar.rb
@@ -0,0 +1,137 @@
+module Grammar
+
+class T
+  attr_accessor :word
+
+  def initialize word
+    @word = word
+  end
+
+  def to_s
+    @word
+  end
+end
+
+class NT
+  attr_accessor :symbol, :index
+
+  def initialize symbol=nil, index=-1
+    @symbol = symbol
+    @index  = index
+  end
+
+  #FIXME? symbol should not contain [, ] or ",
+  #       else we're in trouble
+  def from_s s
+    @symbol, @index = s.delete('[]').split ','
+    @symbol.strip!
+    @index = @index.to_i-1
+  end
+
+  def self.from_s s
+    new = NT.new
+    new.from_s s
+    return new
+  end
+
+  #FIXME? indexed by 1
+  def to_s
+    return "[#{@symbol},#{@index+1}]" if @index>=0
+    return "[#{@symbol}]"
+  end
+end
+
+class Rule
+  attr_accessor :lhs, :rhs, :target, :map, :f
+
+  def initialize lhs=NT.new, rhs=[], target=[], map=[], f=SparseVector.new, arity=0
+    @lhs    = lhs
+    @rhs    = rhs
+    @target = target
+    @map    = map
+    @f      = f
+    @arity  = arity
+  end
+
+  def read_rhs_ s, make_meta=false
+    a = []
+    s.split.map { |x|
+      x.strip!
+      if x[0] == '[' && x[x.size-1] == ']'
+        a << NT.from_s(x)
+        if make_meta
+          @map << a.last.index
+          @arity += 1
+        end
+      else
+        a << T.new(x)
+      end
+    }
+    return a
+  end
+
+  def from_s s
+    lhs, rhs, target, f = splitpipe s, 3
+    @lhs    = NT.from_s lhs
+    @rhs    = read_rhs_ rhs, true
+    @target = read_rhs_ target
+    @f      = (f ? SparseVector.from_kv(f, '=', ' ') : SparseVector.new)
+  end
+
+  def self.from_s s
+    r = Rule.new
+    r.from_s s
+    return r
+  end
+
+  def to_s
+    "#{@lhs.to_s} ||| #{@rhs.map { |x| x.to_s }.join ' '} ||| #{@target.map { |x| x.to_s }.join ' '}"
+  end
+end
+
+class Grammar
+  attr_accessor :rules, :start_nt, :start_t, :flat
+
+  def initialize fn
+    @rules = []; @start_nt = []; @start_t = []; @flat = []
+    n = 0
+    ReadFile.readlines_strip(fn).each_with_index { |s,i|
+      STDERR.write '.'; STDERR.write " #{i+1}\n" if (i+1)%40==0
+      n += 1
+      @rules << Rule.from_s(s)
+      if @rules.last.rhs.first.class == NT
+        @start_nt << @rules.last
+      else
+        if rules.last.arity == 0
+          @flat << @rules.last
+        else
+          @start_t << @rules.last
+        end
+      end
+    }
+    STDERR.write " #{n}\n"
+  end
+
+  def to_s
+    @rules.map { |r| r.to_s }.join "\n"
+  end
+
+  def add_glue
+    @rules.map { |r| r.lhs.symbol }.select { |s| s != 'S' }.uniq.each { |symbol|
+      @rules << Rule.new(NT.new('S'), [NT.new(symbol, 0)], [NT.new(symbol, 0)], [0])
+      @start_nt << @rules.last
+      @rules << Rule.new(NT.new('S'), [NT.new('S', 0), NT.new('X', 1)], [NT.new('S', 0), NT.new('X', 1)], [0, 1])
+      @start_nt << @rules.last
+    }
+  end
+
+  def add_pass_through a
+    a.each { |word|
+      @rules << Rule.new(NT.new('X'), [T.new(word)], [T.new(word)])
+      @flat << @rules.last
+    }
+  end
+end
+
+end #module
+