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
|
module Lrama
class Grammar
# _rhs holds original RHS element. Use rhs to refer to Symbol.
class Rule < Struct.new(:id, :_lhs, :lhs, :lhs_tag, :_rhs, :rhs, :token_code, :position_in_original_rule_rhs, :nullable, :precedence_sym, :lineno, keyword_init: true)
attr_accessor :original_rule
def ==(other)
self.class == other.class &&
self.lhs == other.lhs &&
self.lhs_tag == other.lhs_tag &&
self.rhs == other.rhs &&
self.token_code == other.token_code &&
self.position_in_original_rule_rhs == other.position_in_original_rule_rhs &&
self.nullable == other.nullable &&
self.precedence_sym == other.precedence_sym &&
self.lineno == other.lineno
end
# TODO: Change this to display_name
def to_s
l = lhs.id.s_value
r = empty_rule? ? "ε" : rhs.map {|r| r.id.s_value }.join(" ")
"#{l} -> #{r}"
end
# Used by #user_actions
def as_comment
l = lhs.id.s_value
r = empty_rule? ? "%empty" : rhs.map(&:display_name).join(" ")
"#{l}: #{r}"
end
def with_actions
"#{to_s} {#{token_code&.s_value}}"
end
# opt_nl: ε <-- empty_rule
# | '\n' <-- not empty_rule
def empty_rule?
rhs.empty?
end
def precedence
precedence_sym&.precedence
end
def initial_rule?
id == 0
end
def translated_code
return nil unless token_code
Code::RuleAction.new(type: :rule_action, token_code: token_code, rule: self).translated_code
end
end
end
end
|
