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
|
# frozen_string_literal: true
module Parser
# Stack that holds names of current arguments,
# i.e. while parsing
# def m1(a = (def m2(b = def m3(c = 1); end); end)); end
# ^
# stack is [:a, :b, :c]
#
# Emulates `p->cur_arg` in MRI's parse.y
#
# @api private
#
class CurrentArgStack
attr_reader :stack
def initialize
@stack = []
freeze
end
def empty?
@stack.size == 0
end
def push(value)
@stack << value
end
def set(value)
@stack[@stack.length - 1] = value
end
def pop
@stack.pop
end
def reset
@stack.clear
end
def top
@stack.last
end
end
end
|
