[Pharo-users] String to number conversion issues

Hi, I need to convert web input (Strings) to decimal numbers. I have a regex that will recognize numeric strings, but not all of them can be converted to a number with asNumber. For example, anything with a leading $+ fails, as does anything beginning with '.' (even though .3 isNumber answers true.) or '-.' Is there any code for dealing with this kind of thing (ie a method to be called before calling asNumber or a more robust library for string conversions? Given that all web input is strings and a lot of it is decimal numbers, i have to believe there is code somewhere that does this safely, maybe even with tests. :) Thanks.