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
|
# frozen_string_literal: true
begin
require 'ripper'
rescue LoadError
end
module Temple
module Filters
# Compile [:dynamic, "foo#{bar}"] to [:multi, [:static, 'foo'], [:dynamic, 'bar']]
class StringSplitter < Filter
if defined?(Ripper) && Ripper.respond_to?(:lex)
class << self
# `code` param must be valid string literal
def compile(code)
[].tap do |exps|
tokens = Ripper.lex(code.strip)
tokens.pop while tokens.last && [:on_comment, :on_sp].include?(tokens.last[1])
if tokens.size < 2
raise(FilterError, "Expected token size >= 2 but got: #{tokens.size}")
end
compile_tokens!(exps, tokens)
end
end
private
def strip_quotes!(tokens)
_, type, beg_str = tokens.shift
if type != :on_tstring_beg
raise(FilterError, "Expected :on_tstring_beg but got: #{type}")
end
_, type, end_str = tokens.pop
if type != :on_tstring_end
raise(FilterError, "Expected :on_tstring_end but got: #{type}")
end
[beg_str, end_str]
end
def compile_tokens!(exps, tokens)
beg_str, end_str = strip_quotes!(tokens)
until tokens.empty?
_, type, str = tokens.shift
case type
when :on_tstring_content
beg_str, end_str = escape_quotes(beg_str, end_str)
exps << [:static, eval("#{beg_str}#{str}#{end_str}").to_s]
when :on_embexpr_beg
embedded = shift_balanced_embexpr(tokens)
exps << [:dynamic, embedded] unless embedded.empty?
end
end
end
# Some quotes are split-unsafe. Replace such quotes with null characters.
def escape_quotes(beg_str, end_str)
case [beg_str[-1], end_str]
when ['(', ')'], ['[', ']'], ['{', '}']
[beg_str.sub(/.\z/) { "\0" }, "\0"]
else
[beg_str, end_str]
end
end
def shift_balanced_embexpr(tokens)
String.new.tap do |embedded|
embexpr_open = 1
until tokens.empty?
_, type, str = tokens.shift
case type
when :on_embexpr_beg
embexpr_open += 1
when :on_embexpr_end
embexpr_open -= 1
break if embexpr_open == 0
end
embedded << str
end
end
end
end
def on_dynamic(code)
return [:dynamic, code] unless string_literal?(code)
return [:dynamic, code] if code.include?("\n")
temple = [:multi]
StringSplitter.compile(code).each do |type, content|
case type
when :static
temple << [:static, content]
when :dynamic
temple << on_dynamic(content)
end
end
temple
end
private
def string_literal?(code)
return false if SyntaxChecker.syntax_error?(code)
type, instructions = Ripper.sexp(code)
return false if type != :program
return false if instructions.size > 1
type, _ = instructions.first
type == :string_literal
end
class SyntaxChecker < Ripper
class ParseError < StandardError; end
def self.syntax_error?(code)
self.new(code).parse
false
rescue ParseError
true
end
private
def on_parse_error(*)
raise ParseError
end
end
else
# Do nothing if ripper is unavailable
def call(ast)
ast
end
end
end
end
end
|
