[COFF] Re: Requesting thoughts on extended regular expressions in grep.

I have made an attempt to make my RE stuff readable and supportable. I think I write more description that I do RE "code". As for, *it won't be comprehendable,* Machine language was unreadable and then along came assembly language. Assembly language was unreadable, then came higher level languages. Even higher level languages are unsupportable if not well documented and mostly simple to understand ("you are not expected to understand this" notwithstanding). The jump from machine language to python today was unimagined in early times. [ As an old timer, I see inflection points between: machine language and assembly language assembly language and high level languages and high level languages and python. But that's just me. ] I think it is possible to make a 50K RE that is understandable. However, it requires a lot of 'splainin' throughout the code. I'm naive though; I will eventually discover a lack of truth in that belief, if such exists. I repeat. I put stuff down for months at a time. My metric is *coming back to it* *and understanding where I left off*. So far, I can do that for this RE program that works for small files, large files, binary files and text files for exactly one pattern: YYYY[-MM-DD] I constructed this RE with code like this: # ymdt is YYYY-MM-DD RE in text. # looking only for 1900s and 2000s years and no later than today. _YYYY = "(19\d\d|20[01]\d|202" + "[0-" + lastYearRE) + "]" + "){1}" # months _MM = "(0[1-9]|1[012])" # days _DD = "(0[1-9]|[12]\d|3[01])" ymdt = _YYYY + '[' + _INTERNALSEP + _MM + _INTERNALSEP + ']'{0,1) For the whole file, RE I used ymdthf = _FRSEP + ymdt + _BASEP where FRSEP is front separator which includes a bunch of possible separators, excluding numbers and letters, or-ed with the up arrow "beginning of line" RE mark. BASEP is back separator is same as FRSEP with "^" replaced with "$". I then aimed ymdthf at "data" the thing that represents the entire memory mapped file (where there is only one beginning and one end). Again, I say validating an RE is as difficult or more than writing one. What does it miss? Dates are an excellent test ground for RE's. Latitude and longitude is another. Ed PS: I thought I was on the COFF mailing list. I received this email by direct mail to from Larry. I haven't seen any other comments on my submission. I might have unsubscribed, but now I regret it. Dear powers that be: Please resubscribe me.