From: "ako..." <akonsu@...>
Date: 2005-12-14T11:27:39+09:00
Subject: parsing literals

hello,

i need to write a function that would parse a string literal in another
language. a string literal in this language is:

STRING = "CHAR*"
CHAR = any character except for " and \
  | \"
  | \\
  | \/
  | \u four hexadecimal digits

the \u sequence specifies a character in UTF-16 encoding.

for example: "abc", "", "a\"bc", "a\\b", "a\u12bfc"

below is the code that i wrote. is this Ruby enough? can someone
suggest improvements? a better style?

thanks
konstantin

def parselit(s)
  r = %r{\\"|\\/|\\\\|\\u[\da-f][\da-f][\da-f][\da-f]}i
  s =~ /^"((?:[^"\\]|#{r})*)"$/ && $1.gsub(r) { |x| x =~ /\\u(.*)/ ?
[$1.hex].pack('U*') : x[1..-1] }
end

puts parselit('"\u004e\"a"')