I have a list of measurements that need to be deconstructed into quantity (numeric) and unit (string). Things like
1 gal.
500lbs
none
2.25gal
4feet twine
2lbs regular and 2lbs lite
All was well and good using \d+(\.\d+)?, but now I have a fraction thrown into the mix:
3/4gal
I need to exclude the fraction from this search so that I can deal with it separately. I'm successfully excluding the numerator (3) by inserting a negative lookahead-- \d+(?!\/)(\.\d+)?, but I can't figure out how to exclude the denominator (4). I think I'm supposed to use a negative lookbehind but I can't figure out how. \d+(?!\/)(?<!\/)(\.\d+)? and \d+(?!\/)(\.\d+)?(?<!\/) still match the 4.
Thanks!
In a construct like this \d+(?!\/)(?<!\/)(\.\d+)? the lookbehind (?<!\/) is always true as the only thing you can match (not assert) before is a digit.
You might also exclude a / on the left of the digits part, and add the lookahead after matching the decimal part.
(?<!/)\d+(?:\.\d+)?(?!/)
Explanation
(?<!/) Negative lookbehind, assert directly to the left of the current postion is not /\d+ Match 1+ digits(?:\.\d+)? Match an optional . and 1+ digits(?!/) Negative lookahead, assert directly to the right of the current position is not /