Class: Antlr4::Runtime::PredictionMode
- Inherits:
-
Object
- Object
- Antlr4::Runtime::PredictionMode
show all
- Defined in:
- lib/antlr4/runtime/prediction_mode.rb
Defined Under Namespace
Classes: AltAndContextConfigEqualityComparator, AltAndContextMap
Constant Summary
collapse
- SLL =
0
- LL =
1
- LL_EXACT_AMBIG_DETECTION =
2
Class Method Summary
collapse
Instance Method Summary
collapse
Class Method Details
.all_configs_in_rule_stop_states?(configs) ⇒ Boolean
72
73
74
75
76
77
78
79
80
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 72
def self.all_configs_in_rule_stop_states?(configs)
i = 0
while i < configs.configs.length
return false unless configs.configs[i].state.is_a? RuleStopState
i += 1
end
true
end
|
.all_subsets_conflict?(altsets) ⇒ Boolean
86
87
88
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 86
def self.all_subsets_conflict?(altsets)
!has_non_conflicting_alt_set?(altsets)
end
|
.conflicting_alt_subsets(configs) ⇒ Object
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 154
def self.conflicting_alt_subsets(configs)
config_to_alts = AltAndContextMap.new
i = 0
while i < configs.configs.length
c = configs.configs[i]
alts = config_to_alts.get(c)
if alts.nil?
alts = BitSet.new
config_to_alts.put(c, alts)
end
alts.set(c.alt)
i += 1
end
config_to_alts.values
end
|
.get_alts1(altsets) ⇒ Object
132
133
134
135
136
137
138
139
140
141
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 132
def self.get_alts1(altsets)
all = BitSet.new
i = 0
while i < altsets.length
alts = altsets[i]
all.or(alts)
i += 1
end
all
end
|
.has_config_in_rule_stop_state?(configs) ⇒ Boolean
62
63
64
65
66
67
68
69
70
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 62
def self.has_config_in_rule_stop_state?(configs)
i = 0
while i < configs.configs.length
return true if configs.configs[i].state.is_a? RuleStopState
i += 1
end
false
end
|
.has_conflicting_alt_set?(altsets) ⇒ Boolean
100
101
102
103
104
105
106
107
108
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 100
def self.has_conflicting_alt_set?(altsets)
i = 0
while i < altsets.length
alts = altsets[i]
return true if alts.cardinality > 1
i += 1
end
false
end
|
.has_non_conflicting_alt_set?(altsets) ⇒ Boolean
90
91
92
93
94
95
96
97
98
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 90
def self.has_non_conflicting_alt_set?(altsets)
i = 0
while i < altsets.length
alts = altsets[i]
return true if alts.cardinality == 1
i += 1
end
false
end
|
.has_sll_conflict_terminating_prediction(mode, configs) ⇒ Object
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
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 29
def self.has_sll_conflict_terminating_prediction(mode, configs)
return true if all_configs_in_rule_stop_states?(configs)
if mode == PredictionMode::SLL
if configs.has_semantic_context
dup = ATNConfigSet.new
i = 0
while i < configs.configs.length
cfg = configs.configs[i]
c = ATNConfig.new
c.atn_config5(cfg, SemanticContext::NONE)
dup.add(c)
i += 1
end
configs = dup
end
end
alt_sets = conflicting_alt_subsets(configs)
heuristic = has_conflicting_alt_set?(alt_sets) && !has_state_associated_with_one_alt?(configs)
heuristic
end
|
.has_state_associated_with_one_alt?(configs) ⇒ Boolean
186
187
188
189
190
191
192
193
194
195
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 186
def self.has_state_associated_with_one_alt?(configs)
x = state_to_alt_map(configs)
i = 0
while i < x.values.length
alts = x.values[i]
return true if alts.cardinality == 1
i += 1
end
false
end
|
.resolves_to_just_one_viable_alt?(altsets) ⇒ Boolean
82
83
84
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 82
def self.resolves_to_just_one_viable_alt?(altsets)
single_viable_alt(altsets)
end
|
.single_viable_alt(altsets) ⇒ Object
197
198
199
200
201
202
203
204
205
206
207
208
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 197
def self.single_viable_alt(altsets)
viable_alts = BitSet.new
i = 0
while i < altsets.length
alts = altsets[i]
min_alt = alts.next_set_bit(0)
viable_alts.set(min_alt)
return ATN::INVALID_ALT_NUMBER if viable_alts.cardinality > 1 i += 1
end
viable_alts.next_set_bit(0)
end
|
.state_to_alt_map(configs) ⇒ Object
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 170
def self.state_to_alt_map(configs)
m = {}
i = 0
while i < configs.configs.length
c = configs.configs[i]
alts = m[c.state]
if alts.nil?
alts = BitSet.new
m[c.state] = alts
end
alts.set(c.alt)
i += 1
end
m
end
|
.unique_alt(altsets) ⇒ Object
125
126
127
128
129
130
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 125
def self.unique_alt(altsets)
all = get_alts1(altsets)
return all.next_set_bit(0) if all.cardinality == 1
ATN::INVALID_ALT_NUMBER
end
|
Instance Method Details
#all_subsets_equal?(altsets) ⇒ Boolean
110
111
112
113
114
115
116
117
118
119
120
121
122
123
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 110
def all_subsets_equal?(altsets)
first = nil
i = 0
while i < altsets.length
alt = altsets[i]
if i == 0
first = altsets[0]
else
return false unless alt.eql?(first)
end
i += 1
end
true
end
|
#get_alts2(configs) ⇒ Object
143
144
145
146
147
148
149
150
151
152
|
# File 'lib/antlr4/runtime/prediction_mode.rb', line 143
def get_alts2(configs)
alts = BitSet.new
i = 0
while i < configs.length
config = configs[i]
alts.set(config.alt)
i += 1
end
alts
end
|