1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
#!/usr/bin/env ruby
require_relative './grammar.rb'
STDOUT.sync = true
class Chart
def initialize n
@m = []
(n+1).times {
_ = []
(n+1).times { _ << [] }
@m << _
}
@b = {}
end
def at i, j
@m[i][j]
end
def add i, j, item
at(i,j) << item
@b["#{i},#{j},#{item.lhs.symbol}"] = true
end
def has symbol, i, j
return @b["#{i},#{j},#{symbol}"]
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, left, right, dot
@lhs = rule_or_item.lhs
@rhs = rule_or_item.rhs.dup
@span = Span.new left, right
@dot = dot
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 init input, n, active_chart, passive_chart, grammar
grammar.flat.each { |r|
input.each_index { |i|
if input[i, r.rhs.size] == r.rhs.map { |x| x.word }
new_item = Item.new r, i, i+r.rhs.size, r.rhs.size
passive_chart.add i, i+r.rhs.size, new_item
end
}
}
end
def scan item, input, limit, passive_chart
while item.rhs[item.dot].class == T && item.span.right < limit
if item.rhs[item.dot].word == input[item.span.right]
item.dot += 1
item.span.right += 1
else
break
end
end
end
def parse input, n, active_chart, passive_chart, grammar
2.upto(n) { |span| # outer loop
0.upto(n-span) { |k|
puts " span(#{k},#{k+span})"
# try to apply rules starting with T
grammar.mixed.select { |r| r.rhs.first.word == input[k] }.each { |r|
new_item = Item.new r, k, k, 0
scan new_item, input, k+span, passive_chart
active_chart.at(k,k+span) << new_item
}
# seed active chart
grammar.rewrite.each { |r|
next if r.rhs.size > span
active_chart.at(k,k+span) << Item.new(r, k, k, 0)
}
active_chart.at(k,k+span).each { |active_item|
next if active_item.rhs[active_item.dot].class==T
# inner loop
1.upto(span-1) { |span2|
k.upto((k+span)-span2) { |l|
if passive_chart.has active_item.rhs[active_item.dot].symbol, l, l+span2
if l == active_item.span.right
new_item = Item.new active_item, active_item.span.left, l+span2, active_item.dot+1
scan new_item, input, k+span, passive_chart
if new_item.dot == new_item.rhs.size # done with item
if new_item.span.left == k && new_item.span.right == k+span
passive_chart.add k, k+span, new_item
end
else
if new_item.rhs[new_item.dot].class == NT && new_item.span.right+(new_item.rhs.size-(new_item.dot)) <= k+span
active_chart.at(k,k+span) << new_item
end
end
end
end
}
}
}
# 'self-filling' step
passive_chart.at(k,k+span).each { |passive_item|
active_chart.at(k,k+span).each { |active_item|
next if active_item.rhs[active_item.dot].class!=NT
if passive_item.lhs.symbol == active_item.rhs[active_item.dot].symbol
next if not active_item.span.right==passive_item.span.left
new_item = Item.new active_item, active_item.span.left, passive_item.span.right, active_item.dot+1
scan new_item, input, k+span, passive_chart
if new_item.dot == new_item.rhs.size
if new_item.span.left == k && new_item.span.right == k+span
passive_chart.add k, k+span, new_item
else
puts "#{new_item}" # FIXME never happens
end
else
if new_item.rhs[new_item.dot].class == NT && new_item.span.right+(new_item.rhs.size-(new_item.dot)) <= k+span
puts "NA@#{k},#{k+span} #{new_item}"
active_chart.at(k,k+span) << new_item
end
end
end
}
}
}
}
end
def visit n, depth, skip=0 # FIXME
(depth-skip).times { |i|
i += skip
0.upto(n-(i+1)) { |j|
yield j, j+i+1
}
}
end
def main
#input = 'ich sah ein kleines haus'.split
input = 'lebensmittel schuld an europäischer inflation'.split
#input = 'offizielle prognosen sind von nur 3 prozent ausgegangen , meldete bloomberg .'.split
n = input.size
grammar = Grammar.new 'example/grammar.x'
grammar.add_glue_rules
passive_chart = Chart.new n
active_chart = Chart.new n
init input, n, active_chart, passive_chart, grammar
parse input, n, active_chart, passive_chart, grammar
puts "---\npassive chart"
visit(n, n, 0) { |i,j| puts "#{i},#{j}"; passive_chart.at(i,j).each { |item| puts ' '+item.to_s }; puts }
end
main
|
