1  # coding: utf-8
   2  # frozen_string_literal: true
   3 
   4 
   5 
   6  module Umu
   7 
   8  module Escape
   9 
  10  EACAPE_PAIRS = [
  11      ["\\n",     "\n"],
  12      ["\\t",     "\t"],
  13      ["\\\"",    "\""],
  14      ["\\\\",    "\\"]
  15  ]
  16 
  17  MAP_OF_UNESCAPE_TO_ESCAPE = EACAPE_PAIRS.inject({}) { |hash, (unesc, esc)|
  18      hash.merge(unesc => esc) { |key, _, _|
  19          ASSERT.abort format("Duplicated unescape-char: '%s'", key)
  20      }
  21  }
  22 
  23  MAP_OF_ESCAPE_TO_UNESCAPE = EACAPE_PAIRS.inject({}) { |hash, (unesc, esc)|
  24      hash.merge(esc => unesc) { |key, _, _|
  25          ASSERT.abort format("Duplicated escape-char: '%s'", key)
  26      }
  27  }
  28 
  29 
  30  module_function
  31 
  32      def opt_escape(unesc)
  33          ASSERT.kind_of unesc, ::String
  34 
  35          opt_esc = MAP_OF_UNESCAPE_TO_ESCAPE[unesc]
  36 
  37          ASSERT.opt_kind_of opt_esc.freeze, ::String
  38      end
  39 
  40 
  41      def unescape(esc)
  42          ASSERT.kind_of esc, ::String
  43 
  44          esc.each_char.map { |esc_char|
  45              opt_unesc_char = MAP_OF_ESCAPE_TO_UNESCAPE[esc_char]
  46 
  47              if opt_unesc_char
  48                  opt_unesc_char
  49              else
  50                  esc_char
  51              end
  52          }.join
  53      end
  54 
  55 
  56      def find_escape(unesc)
  57          ASSERT.kind_of unesc, ::String
  58 
  59          opt_esc = unesc.each_char.find { |unesc_char|
  60              ! MAP_OF_ESCAPE_TO_UNESCAPE[unesc_char].nil?
  61          }
  62 
  63          ASSERT.opt_kind_of opt_esc.freeze, ::String
  64      end
  65 
  66  end # Umu::Escape
  67 
  68  end # Umu