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#!/usr/bin/env ruby
require_relative './grammar.rb'
STDOUT.sync = true
class Chart
attr_accessor :has
def initialize n
@m = []
(n+1).times {
_ = []
(n+1).times { _ << [] }
@m << _
}
@has = {}
end
def at i, j
@m[i][j]
end
def add rule_or_item, i, j, right, dot=0
item = Item.new(rule_or_item)
item.span.left = i
item.span.right = right
item.dot = dot
at(i, j) << item
end
end
class Span
attr_accessor :left, :right
def initialize left=nil, right=nil
@left = left
@right = right
end
end
class Item < Rule
attr_accessor :lhs, :rhs, :span, :dot
def initialize rule_or_item
@lhs = rule_or_item.lhs.dup
@rhs = rule_or_item.rhs.dup
if rule_or_item.class == Item
@span = Span.new rule_or_item.span.left, rule_or_item.span.right
@dot = rule_or_item.dot
else
@span = Span.new
@dot = 0
end
end
def to_s
"#{lhs} -> #{rhs.map{|i|i.to_s}.insert(@dot,'*').join ' '} [dot@#{@dot}] [arity=#{arity}] (#{@span.left}, #{@span.right})"
end
end
def visit n, depth, skip=0
(depth-skip).times { |i|
i += skip
0.upto(n-(i+1)) { |j|
yield j, j+i+1
}
}
end
def preprocess s
s.split.map { |i| T.new i }
end
def init input, n, active_chart, passive_chart, grammar
grammar.rules.select { |r| r.arity==0 }.each { |r|
input.each_index { |i|
if input[i, r.rhs.size].map{|x|x.word}==r.rhs.map{|x|x.word}
passive_chart.add Item.new(r), i, i+r.rhs.size, i+r.rhs.size, r.rhs.size
passive_chart.d["#{i},#{i+r.rhs.size},#{r.lhs.symbol}"] = true
end
}
}
end
def scan item, passive_chart, input
while item.rhs[item.dot].class == T
break if item.span.right > input.size-1
if item.rhs[item.dot].word == input[item.span.right].word
item.dot += 1
item.span.right += 1
break if item.dot == item.rhs.size
else
break
end
end
end
def parse input, n, active_chart, passive_chart, grammar
rules_starting_with_t = grammar.rules.select { |r| r.arity > 0 && r.rhs.first.class==T }
rules_starting_with_nt = grammar.rules.select { |r| r.rhs.first.class == NT }
# outer loop
2.upto(n) { |span|
0.upto(n-span) { |k|
# try to apply rules starting with T
rules_starting_with_t.select { |r| r.rhs.first.word == input[k].word }.each { |r|
new_item = Item.new r
new_item.span.left = k
new_item.span.right = k
new_item.dot = 0
scan new_item, passive_chart, input
active_chart.at(k, k+span) << new_item if new_item.span.right < k+span
}
# seed active chart
rules_starting_with_nt.each { |r|
# no eps-productions!
next if r.rhs.size > span
#puts "#{r.rhs.size} #{span}"
new_item = Item.new r
new_item.span.left = k
new_item.span.right = k
new_item.dot = 0
active_chart.at(k, k+span) << new_item
}
puts "#{k} #{k+span}"
# inner loop
puts "SIZE #{active_chart.at(k,k+span).size}"
while !active_chart.at(k,k+span).empty?
active_item = active_chart.at(k, k+span).pop
1.upto(span-1) { |span2|
k.upto((k+span)-span2) { |l|
#puts "passive chart sz #{passive_chart.at(l, l+span2).size} #{l},#{l+span2}"
#passive_chart.at(l, l+span2).select { |item| item.lhs.symbol==active_item.rhs[active_item.dot].symbol }.each { |passive_item|
# if l==0&&span2==2
# puts " #{passive_item}"
# end
if passive_chart.d["#{l},#{l+span2},#{active_item.rhs[active_item.dot].symbol}"]
if l == active_item.span.right
new_item = Item.new active_item
new_item.span.left = active_item.span.left
new_item.span.right = l+span2
new_item.dot += 1
scan new_item, passive_chart, input
if new_item.dot == new_item.rhs.size
if new_item.span.left==k&&new_item.span.right==(k+span)
#puts "NP@#{k},#{k+span} #{new_item}"
passive_chart.at(k,k+span) << new_item
end
else
if new_item.rhs[new_item.dot].class==NT && new_item.span.right < (k+span)
#puts "NA@#{k},#{k+span} #{new_item}"
active_chart.at(k,k+span) << new_item
end
end
end
#}
end
# # try to advance items
# passive_chart.at(l, l+span2).each { |passive_item|
# active_chart.at(k, k+span).select { |active_item| active_item.rhs[active_item.dot].symbol == passive_item.lhs.symbol }.each { |active_item|
# if passive_item.span.left == active_item.span.right
# new_item = Item.new active_item
# new_item.span.left = active_item.span.left
# new_item.span.right = passive_item.span.right
# new_item.dot += 1
# scan new_item, passive_chart, input
# if new_item.dot == new_item.rhs.size
# if new_item.span.left==k&&new_item.span.right==(k+span)
# puts "NP@#{k},#{k+span} #{new_item}"
# passive_chart.at(k,k+span) << new_item
# end
# else
# # item is dead unless it has an NT to fill
# if new_item.rhs[new_item.dot].class==NT && new_item.span.right < (k+span)
# puts "NA@#{k},#{k+span} #{new_item}"
# active_chart.at(k,k+span) << new_item
# end
# end
# end
# }
# }
#
}
}
end
}
}
end
def main
#input = preprocess 'ich sah ein kleines haus'
#input = preprocess 'lebensmittel schuld an europäischer inflation'
input = preprocess 'offizielle prognosen sind von nur 3 prozent ausgegangen , meldete bloomberg .'
n = input.size
g = Grammar.new 'example/grammar.3.gz'
#g.add_glue_rules
passive_chart = Chart.new n
active_chart = Chart.new n
init input, n, active_chart, passive_chart, g
parse input, n, active_chart, passive_chart, g
#puts "---\npassive chart"
#visit(n, n, 0) { |i,j| puts "#{i},#{j}"; passive_chart.at(i,j).each { |item| puts ' '+item.to_s if item.span.left==i&&item.span.right==j }; puts }
#puts "\nactive chart"
#visit(n, n, 0) { |i,j| puts "#{i},#{j}"; active_chart.at(i,j).each { |item| puts ' '+item.to_s }; puts }
end
main
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