Safe user-facing pattern matching.

[Jorge <xxopxe@...>]

As we all know, patterns can be crafted to hog the CPU. Suppose you want 
to offer the possibility to run user provided patterns on a biggish 
text, let's say trough webpage. What would be the simplest alternative, 
keeping as much expressive power as possible, while being safe, to 
standard Lua patterns?

Jorge