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
|
#--
# DO NOT MODIFY!!!!
# This file is automatically generated by rex 1.0.5
# from lexical definition file "sample/sample.rex".
#++
require 'racc/parser'
#
# sample.rex
# lexical definition sample for rex
#
class Sample < Racc::Parser
require 'strscan'
class ScanError < StandardError ; end
attr_reader :lineno
attr_reader :filename
attr_accessor :state
def scan_setup(str)
@ss = StringScanner.new(str)
@lineno = 1
@state = nil
end
def action
yield
end
def scan_str(str)
scan_setup(str)
do_parse
end
alias :scan :scan_str
def load_file( filename )
@filename = filename
open(filename, "r") do |f|
scan_setup(f.read)
end
end
def scan_file( filename )
load_file(filename)
do_parse
end
def next_token
return if @ss.eos?
# skips empty actions
until token = _next_token or @ss.eos?; end
token
end
def _next_token
text = @ss.peek(1)
@lineno += 1 if text == "\n"
token = case @state
when nil
case
when (text = @ss.scan(/[ \t]+/))
;
when (text = @ss.scan(/\d+/))
action { [:digit, text.to_i] }
when (text = @ss.scan(/\w+/))
action { [:word, text] }
when (text = @ss.scan(/\n/))
;
when (text = @ss.scan(/./))
action { [text, text] }
else
text = @ss.string[@ss.pos .. -1]
raise ScanError, "can not match: '" + text + "'"
end # if
else
raise ScanError, "undefined state: '" + state.to_s + "'"
end # case state
token
end # def _next_token
end # class
|
