Class: MODL::Parser::UnicodeEscapes

Inherits:
Object
  • Object
show all
Defined in:
lib/modl/parser/unicode_escapes.rb

Overview

Escape-sequence replacements for MODL files.

Class Method Summary collapse

Class Method Details

.process(str) ⇒ Object

Replace all unicode escape sequences in the supplied string and return the new value.



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# File 'lib/modl/parser/unicode_escapes.rb', line 31

def self.process(str)
  return str unless str.is_a? String

  start = 0
  result = str
  loop do

    backslash_u = result.index('\u', start)
    tilde_u = result.index('~u', start)

    break if tilde_u.nil? && backslash_u.nil?

    if tilde_u.nil?
      uni_str_idx = backslash_u
    elsif backslash_u.nil?
      uni_str_idx = tilde_u
    else
      uni_str_idx = [backslash_u, tilde_u].min
    end

    break if uni_str_idx + 6 > result.length

    start = uni_str_idx + 1

    next if uni_str_idx > 0 && result[uni_str_idx - 1] == '~'
    next if uni_str_idx > 0 && result[uni_str_idx - 1] == '\\'

    value = result.slice(uni_str_idx + 2, 4).to_i(16)
    uni_val = value.chr(Encoding::UTF_8)
    left = result.slice(0, uni_str_idx)
    right = result.slice(uni_str_idx + 6, result.length)
    result = left + uni_val + right unless right.nil?
    result = left + uni_val if right.nil?
  end
  result
end