diff options
Diffstat (limited to 'lib/puppet_x')
| -rw-r--r-- | lib/puppet_x/augeas/util/parser.rb | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/lib/puppet_x/augeas/util/parser.rb b/lib/puppet_x/augeas/util/parser.rb new file mode 100644 index 0000000..1abf42f --- /dev/null +++ b/lib/puppet_x/augeas/util/parser.rb @@ -0,0 +1,215 @@ +# rubocop:disable Style/Documentation +module PuppetX; end +module PuppetX::Augeas; end +module PuppetX::Augeas::Util; end +# rubocop:enable Style/Documentation + +# Container for helpers to parse user provided data contained in manifests. +module PuppetX::Augeas::Util::Parser + TOKEN_ARRAY_CLOSE = %r{\s*\]\s*} + TOKEN_ARRAY_OPEN = %r{\s*\[\s*} + TOKEN_ARRAY_SEPARATOR = %r{\s*,\s*} + TOKEN_CLOSE_CURLY = %r|}| + TOKEN_DOUBLE_QUOTE = %r{"} + TOKEN_DOUBLE_QUOTE_ESCAPED_CHAR = %r{\\(["\\abtnvfres0-7xu])} + TOKEN_DOUBLE_QUOTE_UNESCAPED_CHAR = %r{[^"\\]} + TOKEN_HEX_CHAR = %r{[0-9a-fA-F]{1,2}} + TOKEN_OCTAL_CHAR = %r{[0-7]{1,3}} + TOKEN_OPEN_CURLY = %r|{| + TOKEN_SINGLE_QUOTE = %r{'} + TOKEN_SINGLE_QUOTE_ESCAPED_CHAR = %r{\\(['\\])} + TOKEN_SINGLE_QUOTE_UNESCAPED_CHAR = %r{[^'\\]} + TOKEN_SPACE = %r{\s} + TOKEN_UNICODE_LONG_HEX_CHAR = %r{[0-9a-fA-F]{1,6}} + TOKEN_UNICODE_SHORT_HEX_CHAR = %r{[0-9a-fA-F]{4}} + + # Parse a string into the (nearly) equivalent Ruby array. This only handles + # arrays with string members (double-, or single-quoted), and does not + # support the full quite of escape sequences that Ruby allows in + # double-quoted strings. + # + # @param [String] The string to be parsed. + # @return [Array<String>] The parsed array elements, including handling any + # escape sequences. + def parse_to_array(string) + s = StringScanner.new(string) + match = array_open(s) + raise "Unexpected character in array at: #{s.rest}" if match.nil? + + array_content = array_values(s) + + match = array_close(s) + raise "Unexpected character in array at: #{s.rest}" if match.nil? || !s.empty? + + array_content + end + + def array_open(scanner) + scanner.scan(TOKEN_ARRAY_OPEN) + end + private :array_open + + def array_close(scanner) + scanner.scan(TOKEN_ARRAY_CLOSE) + end + private :array_close + + def array_separator(scanner) + scanner.scan(TOKEN_ARRAY_SEPARATOR) + end + private :array_separator + + def single_quote_unescaped_char(scanner) + scanner.scan(TOKEN_SINGLE_QUOTE_UNESCAPED_CHAR) + end + private :single_quote_unescaped_char + + def single_quote_escaped_char(scanner) + scanner.scan(TOKEN_SINGLE_QUOTE_ESCAPED_CHAR) && scanner[1] + end + private :single_quote_escaped_char + + def single_quote_char(scanner) + single_quote_escaped_char(scanner) || single_quote_unescaped_char(scanner) + end + private :single_quote_char + + def double_quote_unescaped_char(scanner) + scanner.scan(TOKEN_DOUBLE_QUOTE_UNESCAPED_CHAR) + end + private :double_quote_unescaped_char + + # This handles the possible Ruby escape sequences in double-quoted strings, + # except for \M-x, \M-\C-x, \M-\cx, \c\M-x, \c?, and \C-?. The full list of + # escape sequences, and their meanings is taken from: + # https://github.com/ruby/ruby/blob/90fdfec11a4a42653722e2ce2a672d6e87a57b8e/doc/syntax/literals.rdoc#strings + def double_quote_escaped_char(scanner) + match = scanner.scan(TOKEN_DOUBLE_QUOTE_ESCAPED_CHAR) + return nil if match.nil? + + case scanner[1] + when '\\' then return '\\' + when '"' then return '"' + when 'a' then return "\a" + when 'b' then return "\b" + when 't' then return "\t" + when 'n' then return "\n" + when 'v' then return "\v" + when 'f' then return "\f" + when 'r' then return "\r" + when 'e' then return "\e" + when 's' then return "\s" + when %r{[0-7]} + # Back the scanner up by one byte so we can grab all of the potential + # octal digits at the same time. + scanner.pos = scanner.pos - 1 + octal_character = scanner.scan(TOKEN_OCTAL_CHAR) + + return octal_character.to_i(8).chr + when 'x' + hex_character = scanner.scan(TOKEN_HEX_CHAR) + return nil if hex_character.nil? + + hex_character.to_i(16).chr + when 'u' + return unicode_short_hex_character(scanner) || unicode_long_hex_characters(scanner) + else + # Not a valid escape sequence as far as we're concerned. + return nil + end + end + private :double_quote_escaped_char + + def unicode_short_hex_character(scanner) + unicode_character = scanner.scan(TOKEN_UNICODE_SHORT_HEX_CHAR) + return nil if unicode_character.nil? + + [unicode_character.hex].pack 'U' + end + private :unicode_short_hex_character + + def unicode_long_hex_characters(scanner) + unicode_string = '' + return nil unless scanner.scan(TOKEN_OPEN_CURLY) + + loop do + char = scanner.scan(TOKEN_UNICODE_LONG_HEX_CHAR) + break if char.nil? + unicode_string << [char.hex].pack('U') + + separator = scanner.scan(TOKEN_SPACE) + break if separator.nil? + end + + return nil if scanner.scan(TOKEN_CLOSE_CURLY).nil? || unicode_string.empty? + + unicode_string + end + private :unicode_long_hex_characters + + def single_quoted_string(scanner) + quoted_string = '' + + match = scanner.scan(TOKEN_SINGLE_QUOTE) + return nil if match.nil? + + loop do + match = single_quote_char(scanner) + break if match.nil? + + quoted_string << match + end + + match = scanner.scan(TOKEN_SINGLE_QUOTE) + return quoted_string if match + + nil + end + private :single_quoted_string + + def double_quote_char(scanner) + double_quote_escaped_char(scanner) || double_quote_unescaped_char(scanner) + end + private :double_quote_char + + def double_quoted_string(scanner) + quoted_string = '' + + match = scanner.scan(TOKEN_DOUBLE_QUOTE) + return nil if match.nil? + + loop do + match = double_quote_char(scanner) + break if match.nil? + + quoted_string << match + end + + match = scanner.scan(TOKEN_DOUBLE_QUOTE) + return quoted_string if match + + nil + end + private :double_quoted_string + + def quoted_string(scanner) + single_quoted_string(scanner) || double_quoted_string(scanner) + end + private :quoted_string + + def array_values(scanner) + values = [] + + loop do + match = quoted_string(scanner) + break if match.nil? + values << match + + match = array_separator(scanner) + break if match.nil? + end + + values + end + private :array_values +end |