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
|
module Sass
# A class representing the stack when compiling a Sass file.
class Stack
# TODO: use this to generate stack information for Sass::SyntaxErrors.
# A single stack frame.
class Frame
# The filename of the file in which this stack frame was created.
#
# @return [String]
attr_reader :filename
# The line number on which this stack frame was created.
#
# @return [String]
attr_reader :line
# The type of this stack frame. This can be `:import`, `:mixin`, or
# `:base`.
#
# `:base` indicates that this is the bottom-most frame, meaning that it
# represents a single line of code rather than a nested context. The stack
# will only ever have one base frame, and it will always be the most
# deeply-nested frame.
#
# @return [Symbol?]
attr_reader :type
# The name of the stack frame. For mixin frames, this is the mixin name;
# otherwise, it's `nil`.
#
# @return [String?]
attr_reader :name
def initialize(filename, line, type, name = nil)
@filename = filename
@line = line
@type = type
@name = name
end
# Whether this frame represents an import.
#
# @return [Boolean]
def is_import?
type == :import
end
# Whether this frame represents a mixin.
#
# @return [Boolean]
def is_mixin?
type == :mixin
end
# Whether this is the base frame.
#
# @return [Boolean]
def is_base?
type == :base
end
end
# The stack frames. The last frame is the most deeply-nested.
#
# @return [Array<Frame>]
attr_reader :frames
def initialize
@frames = []
end
# Pushes a base frame onto the stack.
#
# @param filename [String] See \{Frame#filename}.
# @param line [String] See \{Frame#line}.
# @yield [] A block in which the new frame is on the stack.
def with_base(filename, line)
with_frame(filename, line, :base) {yield}
end
# Pushes an import frame onto the stack.
#
# @param filename [String] See \{Frame#filename}.
# @param line [String] See \{Frame#line}.
# @yield [] A block in which the new frame is on the stack.
def with_import(filename, line)
with_frame(filename, line, :import) {yield}
end
# Pushes a mixin frame onto the stack.
#
# @param filename [String] See \{Frame#filename}.
# @param line [String] See \{Frame#line}.
# @param name [String] See \{Frame#name}.
# @yield [] A block in which the new frame is on the stack.
def with_mixin(filename, line, name)
with_frame(filename, line, :mixin, name) {yield}
end
# Pushes a function frame onto the stack.
#
# @param filename [String] See \{Frame#filename}.
# @param line [String] See \{Frame#line}.
# @param name [String] See \{Frame#name}.
# @yield [] A block in which the new frame is on the stack.
def with_function(filename, line, name)
with_frame(filename, line, :function, name) {yield}
end
# Pushes a function frame onto the stack.
#
# @param filename [String] See \{Frame#filename}.
# @param line [String] See \{Frame#line}.
# @param name [String] See \{Frame#name}.
# @yield [] A block in which the new frame is on the stack.
def with_directive(filename, line, name)
with_frame(filename, line, :directive, name) {yield}
end
def to_s
(frames.reverse + [nil]).each_cons(2).each_with_index.
map do |(frame, caller), i|
"#{i == 0 ? 'on' : 'from'} line #{frame.line}" +
" of #{frame.filename || 'an unknown file'}" +
(caller && caller.name ? ", in `#{caller.name}'" : "")
end.join("\n")
end
private
def with_frame(filename, line, type, name = nil)
@frames.pop if @frames.last && @frames.last.type == :base
@frames.push(Frame.new(filename, line, type, name))
yield
ensure
@frames.pop unless type == :base && @frames.last && @frames.last.type != :base
end
end
end
|
