From: Josselin <josselin@...>
Date: 2007-10-02T20:40:05+09:00
Subject: help in my own gsub design..

I don't use it very often, rather copying from example, but it's so 
useful that I should learn how to write it
I'd appreciate any guru tip on how to proceed once the problem is on 
the paper :

example :

INPUT STRINGS

1-  input can contains spaces (should be eliminated)

2- good patterns :

2a- an Integer  like 99  (no limit)
a   >   >=  <  <=   <>  !=   followed by an Integer      like   >99   
>=99  <99  <=99  <>99   !=99

2b- a String like:    abcd  abc99  99abc  a99bc

2c- a  % sign  followed by a String
	like  %abcd  %abc99  %99abc  %a99bc %abcd

2d- a    String  followed by a  % sign
	like  abcd%  abc99%  99abc%  a99bc%

2e- a String leading containing or ending with, one or many * sign(s)
	like  a*bcd  a**bc99  99*a*bc  *a99bc a99bc*  *a99bc*     *a9**9b*c*

3-any other pattern will be considered as wrong
	
OUTPUTS

2a ->   an array [characters, Integer]    like   [ "<>", 99]
2b, 2c, 2d,2e  ->  an array [ nil, String]  like  [nil, abcd]  or [nil, 
%abcd] or [nil, a99bc%] or [nil, *a9**9b*c]

I am interesting in understanding the design process... : how should I 
start when designing such gsub routine ?
should I state it differently on paper first ?  well, any tip that can 
help me to build the next ones....

thanks for your support

joss