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 =

Taken from yaml.org/type/timestamp.html

/^\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 =

Taken from yaml.org/type/float.html

/^(?:[-+]?([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
INTEGER =

Taken from yaml.org/type/int.html

/^(?:[-+]?0b[0-1_]+          (?# base 2)
|[-+]?0[0-7_]+           (?# base 8)
|[-+]?(?:0|[1-9][0-9_]*) (?# base 10)
|[-+]?0x[0-9a-fA-F_]+    (?# base 16))$/x

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ScalarScanner

Create a new scanner



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# File 'lib/psych/scalar_scanner.rb', line 23

def initialize
  @string_cache = {}
  @symbol_cache = {}
end

Instance Method Details

#parse_int(string) ⇒ Object

Parse and return an int from string



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# File 'lib/psych/scalar_scanner.rb', line 112

def parse_int string
  return unless INTEGER === string
  Integer(string)
end

#parse_time(string) ⇒ Object

Parse and return a Time from string



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# File 'lib/psych/scalar_scanner.rb', line 119

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



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# File 'lib/psych/scalar_scanner.rb', line 29

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

  case string
  # Check for a String type, being careful not to get caught by hash keys, hex values, and
  # special floats (e.g., -.inf).
  when /^[^\d\.:-]?[A-Za-z_\s!@#\$%\^&\*\(\)\{\}\<\>\|\/\\~;=]+/
    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)$/i
      false
    else
      @string_cache[string] = true
      string
    end
  when TIME
    begin
      parse_time string
    rescue ArgumentError
      string
    end
  when /^\d{4}-(?:1[012]|0\d|\d)-(?:[12]\d|3[01]|0\d|\d)$/
    require 'date'
    begin
      Date.strptime(string, '%Y-%m-%d')
    rescue ArgumentError
      string
    end
  when /^\.inf$/i
    Float::INFINITY
  when /^-\.inf$/i
    -Float::INFINITY
  when /^\.nan$/i
    Float::NAN
  when /^:./
    if string =~ /^:(["'])(.*)\1/
      @symbol_cache[string] = $2.sub(/^:/, '').to_sym
    else
      @symbol_cache[string] = string.sub(/^:/, '').to_sym
    end
  when /^[-+]?[0-9][0-9_]*(:[0-5]?[0-9])+$/
    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_]*$/
    i = 0
    string.split(':').each_with_index do |n,e|
      i += (n.to_f * 60 ** (e - 2).abs)
    end
    i
  when FLOAT
    if string == '.'
      @string_cache[string] = true
      string
    else
      Float(string.gsub(/[,_]|\.$/, ''))
    end
  else
    int = parse_int string.gsub(/[,_]/, '')
    return int if int

    @string_cache[string] = true
    string
  end
end