Why do we have to apologise to those that don't take the time to see beyond the terse but immensely powerful notation that makes up the language 'perl 5 regex'?

My Dad would never have managed to wrap his brain around [(x-h)^2]/a^2 + [(y-k)^2]/b^2 = 1., although that didn't stop him from accurately (within obvious tolorances) cutting an oval from a piece of 1/2 inch ply using nothing but a piece of string, two nails and a piece of chalk.

To him, the whole concept of algebraic notation was an anathema, but it's doubtful if there are many people reading this for whom that formula isn't eminently readable. The difference? Education. My father left school aged 12 and started his 10 years apprenticship as a carpenter aged 14. He never had the opportunity to learn algebra.

The following short extract from here

When ²³⁵U captures a neutron, the resulting ²³⁶U nucleus emits g-rays as it deexcites to the ground state about 15% of the time, and undergoes fission about 85%. The fission process is somewhat analogous to the oscillations of a liquid drop. Using the liquid drop model Bohr and Wheeler calculated the critical energy E_c needed by the ²³⁶U nucleus to undergo fission. For this nucleus, the critical energy is 5.3 MeV, which is less than the 6.4 MeV of excitation energy produced when ²³⁵U captures a neutron. The capture of a neutron by ²³⁵U therefore produces an excited state of ²³⁶U that has more than enough energy to break apart. On the other hand, the critical energy for fission of the ²³⁹U nucleus is 5.9 MeV. The capture of a neutron by a ²³⁸U nucleus produces an excitation energy of only 5.2 MeV. Therefore, when a neutron is captured by ²³⁸U to form ²³⁹U, the excitation energy is not great enough for fission to occur. In this case, the excited ²³⁹U> nucleus deexcites by g-emission, and then decays to Np239 by b-decay, and then again to ²³⁹Pu by b-decay.

A fissioning nucleus can break into 2 medium-mass fragments in many different ways. Depending on the particular reaction, 1, 2 or 3 neutrons may be emitted. The average number of neutrons emitted in the fission of ²³⁵Uis about 2.5.

describes (roughly) the same thing as n + ²³⁵U --> ¹⁴¹Ba + ⁹²Kr + 3n

Now they both mean precious little to me, but to those that live and work in the field of nuclear physics, I'm pretty sure that the latter concise form is an infinitely less unweildy and more practical to work with in correspondance, notes, reports and papers as well as in aggregate works in which this formula is only a part.

In the same way, regexes are simply a short-hand notation that allow the capturing of complex aggregate programming concepts in a concise, weildy fashion.

For people to dismiss regexes, much less the whole of perl(*), as "line noise" because they haven't bothered to take the time to understand them, and the power they represent, requires no apology from us, but from them.

(*) As one who did exactly this, professionally, twice, I hereby apologise to the perl community at large, and Mr. Wall in particular for this heinous crime!

Don't get me wrong, regexes have their place in perl. It's part of what makes perl perl. However, I think that people have the tendency to look at every problem as a regex problem (or more generically as <insert your favorite paradigm here> problem). And, when that happens, you have people writing unnecessarily complex regexen to make the square peg fit in to the round hole. In this case, the OP had a problem where s/he had a delimited record format. If that doesn't scream split, I'll eat my hat. But, the OP had a predisposition towards using regexen at the detriment of not only readability but simplicity.

Also, I take issue (though not on a personal level) with saying that something has to be done in a certain way. Not only are you working to the exclusion of other, possibly better tools, but in some cases, your chosen tool doesn't even make sense.

thor

Also, I take issue (though not on a personal level) with saying that something has to be done in a certain way.

I totally agree with that. Unreservedly.

As for the delimited record format. Maybe I read to much into the post, but I thought that it implied of not stated, that whilst the data was essentially delimited, one or more parts of it had variable numbres of repetitions, and the delimiters were not consistant through out.

Anyway, my tilting at this particular windmill was more a reaction to the general statement about line-noise, rather than aimed at your post specifically:) Just a convenient hook upon which to hang my own bias. Sorry.

I think I'm having a bad day today. Perhaps I should go out and take a walk in the sunshine.

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Examine what is said, not who speaks.
"Efficiency is intelligent laziness." -David Dunham
"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong." -Richard Buckminster Fuller

Good gracious thor, you'd think what I am asking for is a crime against humanity. I already said, I want to capture and validate in one pass (of an ARBITRARY length). TWMTODI anyone? I asked in the hope of expanding my knowledge of regex's on the whole..

It's NOT a predisposition against readability, I just need to get this regex working to the point where I can migrate this from one platform to another. Besides, split forces me to iterate, and have logic to know which filter to run on each element of the inbound data..