Class: Psych::ScalarScanner

Inherits:
Object show all
Defined in:
lib/psych/scalar_scanner.rb

Overview

Scan scalars for built in types

Constant Summary collapse

TIME =
/^\d{4}-\d{1,2}-\d{1,2}([Tt]|\s+)\d{1,2}:\d\d:\d\d(\.\d*)?(\s*Z|[-+]\d{1,2}(:\d\d)?)?/
FLOAT =
/^(?:[-+]?([0-9][0-9_,]*)?\.[0-9.]*([eE][-+][0-9]+)?(?# base 10)
|[-+]?[0-9][0-9_,]*(:[0-5]?[0-9])+\.[0-9_]*(?# base 60)
|[-+]?\.(inf|Inf|INF)(?# infinity)
|\.(nan|NaN|NAN)(?# not a number))$/x

Instance Method Summary collapse

Constructor Details

#initializeScalarScanner

Create a new scanner



17
18
19
# File 'lib/psych/scalar_scanner.rb', line 17

def initialize
  @string_cache = {}
end

Instance Method Details

#parse_time(string) ⇒ Object

Parse and return a Time from string



103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
# File 'lib/psych/scalar_scanner.rb', line 103

def parse_time string
  date, time = *(string.split(/[ tT]/, 2))
  (yy, m, dd) = date.split('-').map { |x| x.to_i }
  md = time.match(/(\d+:\d+:\d+)(?:\.(\d*))?\s*(Z|[-+]\d+(:\d\d)?)?/)

  (hh, mm, ss) = md[1].split(':').map { |x| x.to_i }
  us = (md[2] ? Rational("0.#{md[2]}") : 0) * 1000000

  time = Time.utc(yy, m, dd, hh, mm, ss, us)

  return time if 'Z' == md[3]
  return Time.at(time.to_i, us) unless md[3]

  tz = md[3].match(/^([+\-]?\d{1,2})\:?(\d{1,2})?$/)[1..-1].compact.map { |digit| Integer(digit, 10) }
  offset = tz.first * 3600

  if offset < 0
    offset -= ((tz[1] || 0) * 60)
  else
    offset += ((tz[1] || 0) * 60)
  end

  Time.at((time - offset).to_i, us)
end

#tokenize(string) ⇒ Object

Tokenize string returning the ruby object



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
# File 'lib/psych/scalar_scanner.rb', line 22

def tokenize string
  return nil if string.empty?
  return string if @string_cache.key?(string)

  case string
  when /^[A-Za-z~]/
    if string.length > 5
      @string_cache[string] = true
      return string
    end

    case string
    when /^[^ytonf~]/i
      @string_cache[string] = true
      string
    when '~', /^null$/i
      nil
    when /^(yes|true|on)$/i
      true
    when /^(no|false|off)$/i
      false
    else
      @string_cache[string] = true
      string
    end
  when TIME
    parse_time string
  when /^\d{4}-(?:1[012]|0\d|\d)-(?:[12]\d|3[01]|0\d|\d)$/
    require 'date'
    begin
      Date.strptime(string, '%Y-%m-%d')
    rescue ArgumentError
      string
    end
  when /^\.inf$/i
    1 / 0.0
  when /^-\.inf$/i
    -1 / 0.0
  when /^\.nan$/i
    0.0 / 0.0
  when /^:./
    if string =~ /^:(["'])(.*)\1/
      $2.sub(/^:/, '').to_sym
    else
      string.sub(/^:/, '').to_sym
    end
  when /^[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+$/
    i = 0
    string.split(':').each_with_index do |n,e|
      i += (n.to_i * 60 ** (e - 2).abs)
    end
    i
  when /^[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+\.[0-9_]*$/
    i = 0
    string.split(':').each_with_index do |n,e|
      i += (n.to_f * 60 ** (e - 2).abs)
    end
    i
  when FLOAT
    begin
      return Float(string.gsub(/[,_]/, ''))
    rescue ArgumentError
    end

    @string_cache[string] = true
    string
  else
    if string.count('.') < 2
      begin
        return Integer(string.gsub(/[,_]/, ''))
      rescue ArgumentError
      end
    end

    @string_cache[string] = true
    string
  end
end