I've got a project to do where it requires that some user input fields should have an input mask defined and that the data is validated against these input fields.

I was thinking of following a subset of the Visual Basic definition of input masks which follows:

MASK    Purpose
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~
0    Digit (0 to 9, entry required, plus [+] and minus [–] signs not a
+llowed). 
9    Digit or space (entry not required, plus and minus signs not allo
+wed). 
#    Digit or space (entry not required; plus and minus signs allowed)
L    Letter (A to Z, entry required). 
?    Letter (A to Z, entry optional)*
A    Letter or digit (entry required). 
a    Letter or digit (entry optional)* 
&    Any character or a space (entry required). 
C    Any character or a space (entry optional)*
. , : ; - /    Literal character
<    Causes all characters to be converted to lowercase. 
>    Causes all characters to be converted to uppercase. 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*    may remove this rule
[download]

The reason behind this is that most people I work with are techie enough to come up with input masks but not full regex. For example, its easier to do:

    (C##) ### #######
or
    (+00) 000 0000000
[download]

Than to do

    /^\(\+\d{2}\) \d{3} \d{7}$/
[download]

NB: I just wrote the regex out for an example, I have no idea if it works.

I have scouted around CPAN and found nothing that provides this kind of functionality. However, before I begin work on this I wondered if it had been done before (so I could download and install it) or if anyone had any comments on how to do this? If this doesn't exist anywhere I would consider posting it to CPAN only if nothing was there first.

I thought of simply removing the optional parts to the ruleset and then using something like pack, a dynamic regex or simply iterating through the chars in the string.

The resting place for these masks would be in a database next to the question they ask so would always be dynamic and variable in nature. Additionally, I may have to port this code to JavaScript (*shudder*) for various reasons.

Thanks

SP