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
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
|
require "lrama/report"
module Lrama
# This is passed to a template
class Context
include Report::Duration
ErrorActionNumber = -Float::INFINITY
BaseMin = -Float::INFINITY
# TODO: It might be better to pass `states` to Output directly?
attr_reader :states
def initialize(states)
@states = states
@yydefact = nil
@yydefgoto = nil
# Array of array
@_actions = []
compute_tables
end
# enum yytokentype
def yytokentype
@states.terms.reject do |term|
0 < term.token_id && term.token_id < 128
end.map do |term|
[term.id.s_value, term.token_id, term.display_name]
end.unshift(["YYEMPTY", -2, nil])
end
# enum yysymbol_kind_t
def yysymbol_kind_t
@states.symbols.map do |sym|
[sym.enum_name, sym.number, sym.comment]
end.unshift(["YYSYMBOL_YYEMPTY", -2, nil])
end
# State number of final (accepted) state
def yyfinal
@states.states.find do |state|
state.items.find do |item|
item.rule.lhs.id.s_value == "$accept" && item.end_of_rule?
end
end.id
end
def yylast
@yylast
end
# Number of terms
def yyntokens
@states.terms.count
end
# Number of nterms
def yynnts
@states.nterms.count
end
# Number of rules
def yynrules
@states.rules.count
end
# Number of states
def yynstates
@states.states.count
end
# Last token number
def yymaxutok
@states.terms.map(&:token_id).max
end
# YYTRANSLATE
#
# yytranslate is a mapping from token id to symbol number
def yytranslate
# 2 is YYSYMBOL_YYUNDEF
a = Array.new(yymaxutok, 2)
@states.terms.each do |term|
a[term.token_id] = term.number
end
return a
end
# Mapping from rule number to line number of the rule is defined.
# Dummy rule is appended as the first element whose value is 0
# because 0 means error in yydefact.
def yyrline
a = [0]
@states.rules.each do |rule|
a << rule.lineno
end
return a
end
# Mapping from symbol number to its name
def yytname
@states.symbols.sort_by(&:number).map do |sym|
sym.display_name
end
end
def yypact_ninf
@yypact_ninf
end
def yytable_ninf
@yytable_ninf
end
def yypact
@base[0...yynstates]
end
def yydefact
@yydefact
end
def yypgoto
@base[yynstates..-1]
end
def yydefgoto
@yydefgoto
end
def yytable
@table
end
def yycheck
@check
end
def yystos
@states.states.map do |state|
state.accessing_symbol.number
end
end
# Mapping from rule number to symbol number of LHS.
# Dummy rule is appended as the first element whose value is 0
# because 0 means error in yydefact.
def yyr1
a = [0]
@states.rules.each do |rule|
a << rule.lhs.number
end
return a
end
# Mapping from rule number to lenght of RHS.
# Dummy rule is appended as the first element whose value is 0
# because 0 means error in yydefact.
def yyr2
a = [0]
@states.rules.each do |rule|
a << rule.rhs.count
end
return a
end
private
# Compute these
#
# See also: "src/tables.c" of Bison.
#
# * yydefact
# * yydefgoto
# * yypact and yypgoto
# * yytable
# * yycheck
# * yypact_ninf
# * yytable_ninf
def compute_tables
report_duration(:compute_yydefact) { compute_yydefact }
report_duration(:compute_yydefgoto) { compute_yydefgoto }
report_duration(:sort_actions) { sort_actions }
# debug_sorted_actions
report_duration(:compute_packed_table) { compute_packed_table }
end
def vectors_count
@states.states.count + @states.nterms.count
end
# In compressed table, rule 0 is appended as an error case
# and reduce is represented as minus number.
def rule_id_to_action_number(rule_id)
(rule_id + 1) * -1
end
# Symbol number is assinged to term first then nterm.
# This method calculates sequence_number for nterm.
def nterm_number_to_sequence_number(nterm_number)
nterm_number - @states.terms.count
end
# Vector is states + nterms
def nterm_number_to_vector_number(nterm_number)
@states.states.count + (nterm_number - @states.terms.count)
end
def compute_yydefact
# Default action (shift/reduce/error) for each state.
# Index is state id, value is `rule id + 1` of a default reduction.
@yydefact = Array.new(@states.states.count, 0)
@states.states.each do |state|
# Action number means
#
# * number = 0, default action
# * number = -Float::INFINITY, error by %nonassoc
# * number > 0, shift then move to state "number"
# * number < 0, reduce by "-number" rule. Rule "number" is already added by 1.
actions = Array.new(@states.terms.count, 0)
if state.reduces.map(&:selected_look_ahead).any? {|la| !la.empty? }
# Iterate reduces with reverse order so that first rule is used.
state.reduces.reverse.each do |reduce|
reduce.look_ahead.each do |term|
actions[term.number] = rule_id_to_action_number(reduce.rule.id)
end
end
end
# Shift is selected when S/R conflict exists.
state.selected_term_transitions.each do |shift, next_state|
actions[shift.next_sym.number] = next_state.id
end
state.resolved_conflicts.select do |conflict|
conflict.which == :error
end.each do |conflict|
actions[conflict.symbol.number] = ErrorActionNumber
end
# If default_reduction_rule, replase default_reduction_rule in
# actions with zero.
if state.default_reduction_rule
actions.map! do |e|
if e == rule_id_to_action_number(state.default_reduction_rule.id)
0
else
e
end
end
end
# If no default_reduction_rule, default behavior is an
# error then replase ErrorActionNumber with zero.
if !state.default_reduction_rule
actions.map! do |e|
if e == ErrorActionNumber
0
else
e
end
end
end
s = actions.each_with_index.map do |n, i|
[i, n]
end.select do |i, n|
# Remove default_reduction_rule entries
n != 0
end
if s.count != 0
# Entry of @_actions is an array of
#
# * State id
# * Array of tuple, [from, to] where from is term number and to is action.
# * The number of "Array of tuple" used by sort_actions
# * "width" used by sort_actions
@_actions << [state.id, s, s.count, s.last[0] - s.first[0] + 1]
end
@yydefact[state.id] = state.default_reduction_rule ? state.default_reduction_rule.id + 1 : 0
end
end
def compute_yydefgoto
# Default GOTO (nterm transition) for each nterm.
# Index is sequence number of nterm, value is state id
# of a default nterm transition destination.
@yydefgoto = Array.new(@states.nterms.count, 0)
h = {}
# Mapping from nterm to next_states
nterm_to_next_states = {}
terms_count = @states.terms.count
@states.states.each do |state|
state.nterm_transitions.each do |shift, next_state|
key = shift.next_sym
nterm_to_next_states[key] ||= []
nterm_to_next_states[key] << [state, next_state] # [from_state, to_state]
end
end
@states.nterms.each do |nterm|
if !(states = nterm_to_next_states[nterm])
default_goto = 0
not_default_gotos = []
else
default_state = states.map(&:last).group_by {|s| s }.max_by {|_, v| v.count }.first
default_goto = default_state.id
not_default_gotos = []
states.each do |from_state, to_state|
next if to_state.id == default_goto
not_default_gotos << [from_state.id, to_state.id]
end
end
k = nterm_number_to_sequence_number(nterm.number)
@yydefgoto[k] = default_goto
if not_default_gotos.count != 0
v = nterm_number_to_vector_number(nterm.number)
# Entry of @_actions is an array of
#
# * Nterm number as vector number
# * Array of tuple, [from, to] where from is state number and to is state number.
# * The number of "Array of tuple" used by sort_actions
# * "width" used by sort_actions
@_actions << [v, not_default_gotos, not_default_gotos.count, not_default_gotos.last[0] - not_default_gotos.first[0] + 1]
end
end
end
def sort_actions
# This is not same with #sort_actions
#
# @sorted_actions = @_actions.sort_by do |_, _, count, width|
# [-width, -count]
# end
@sorted_actions = []
@_actions.each do |action|
if @sorted_actions.empty?
@sorted_actions << action
next
end
j = @sorted_actions.count - 1
state_id, froms_and_tos, count, width = action
while (j >= 0) do
case
when @sorted_actions[j][3] < width
j -= 1
when @sorted_actions[j][3] == width && @sorted_actions[j][2] < count
j -= 1
else
break
end
end
@sorted_actions.insert(j + 1, action)
end
end
def debug_sorted_actions
ary = Array.new
@sorted_actions.each do |state_id, froms_and_tos, count, width|
ary[state_id] = [state_id, froms_and_tos, count, width]
end
print sprintf("table_print:\n\n")
print sprintf("order [\n")
vectors_count.times do |i|
print sprintf("%d, ", @sorted_actions[i] ? @sorted_actions[i][0] : 0)
print "\n" if i % 10 == 9
end
print sprintf("]\n\n")
print sprintf("width [\n")
vectors_count.times do |i|
print sprintf("%d, ", ary[i] ? ary[i][3] : 0)
print "\n" if i % 10 == 9
end
print sprintf("]\n\n")
print sprintf("tally [\n")
vectors_count.times do |i|
print sprintf("%d, ", ary[i] ? ary[i][2] : 0)
print "\n" if i % 10 == 9
end
print sprintf("]\n\n")
end
def compute_packed_table
# yypact and yypgoto
@base = Array.new(vectors_count, BaseMin)
# yytable
@table = []
# yycheck
@check = []
# Key is froms_and_tos, value is index position
pushed = {}
userd_res = {}
lowzero = 0
high = 0
@sorted_actions.each do |state_id, froms_and_tos, _, _|
if (res = pushed[froms_and_tos])
@base[state_id] = res
next
end
res = lowzero - froms_and_tos.first[0]
while true do
ok = true
froms_and_tos.each do |from, to|
loc = res + from
if @table[loc]
# If the cell of table is set, can not use the cell.
ok = false
break
end
end
if ok && userd_res[res]
ok = false
end
if ok
break
else
res += 1
end
end
loc = 0
froms_and_tos.each do |from, to|
loc = res + from
@table[loc] = to
@check[loc] = from
end
while (@table[lowzero]) do
lowzero += 1
end
high = loc if high < loc
@base[state_id] = res
pushed[froms_and_tos] = res
userd_res[res] = true
end
@yylast = high
# replace_ninf
@yypact_ninf = (@base.select {|i| i != BaseMin } + [0]).min - 1
@base.map! do |i|
case i
when BaseMin
@yypact_ninf
else
i
end
end
@yytable_ninf = (@table.compact.select {|i| i != ErrorActionNumber } + [0]).min - 1
@table.map! do |i|
case i
when nil
0
when ErrorActionNumber
@yytable_ninf
else
i
end
end
@check.map! do |i|
case i
when nil
-1
else
i
end
end
end
end
end
|