Re: yet another pattern-matching library for Lua

[Paul Smith <paullocal@...>]

> Paul Hudson wrote :
> > > with a gentler learning curve than regular expressions.
> > I accept that people find regexps difficult, but it baffles me 
> > sometimes why. I don't recall(*) having a problem learning them. 
> > What aspects of them do people find difficult?
> > (*) But since I first encountered them about 20 years ago, I may 
> > have forgotten the problems I had.

I think the main problem people have is that they are difficult to 
read 'at a glance'. Once you realise that they are often quite 
comprehensible once you start breaking them down, they become a lot 
easier, but a lot of people will look at them, and because they don't 
understand it immediately, the little switch that says 'I can't do 
this' trips, and they will say that regexps are hard and they can't 
do them without actually trying.

If people were introduced to regexps by things like

gr[ea]y

rather than

\b[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b

they'd probably find them a lot easier... I think the difficulty is 
mainly a mind-set one rather than actual difficulty.

I find http://www.regularexpressions.info/ is a decent tutorial which 
covers the basics quickly, but lets you find out more if you need/want.


Paul                            VPOP3 - Internet Email Server/Gateway
support@pscs.co.uk                      http://www.pscs.co.uk/