I am looking for a good way to convert string like:
"[apples, oranges, [strawberries, peas, grapes]]"
into an array which will look like:
array = [apples, oranges, [strawberries, peas, grapes]].
therefore array[0] = ["apples"], array[1] = ["oranges"], and array[2] = ["strawberries", "peas", "grapes"]
So, whenever in my string I have another inner square brackets, the content between brackets will be a subarray of my base array.
eval s.gsub /\w+/, '"\&"'
or, for an alternative result that might be useful...
eval s.gsub /\w+/, ':\&'
Now, these are vulnerable to code injection exploits if you are not in full control of the input, so you could install a JSON gem and do something like this:
require 'json'
JSON.parse s.gsub /\w+/, '"\&"'
You can use gsub to wrap the words in quotes and then eval the string:
eval str.gsub(/\w+/) { |match| "'#{match}'" }
This assumes that your words are words in the sense of a regex: alphanumeric. Further, this is quick-and-dirty, and I don't recommend using eval if it can be avoided (by, for example, having your input be in a parseable serialization language) as it can be a security risk.
Hm, if your strings would be surrounded by "" it would be easier, than you could just use a JSON parser ;-). But for this you would have to write your own parser. There are different parser generator gems for ruby. E.g.
Parslet: http://kschiess.github.com/parslet/
Treetop: http://treetop.rubyforge.org/
array = [apples, oranges, [strawberries, peas, grapes]], thenarray[0]is not["apples"], nor is it"apples", but is whatever value that is assigned to the variableapples.