I think that what you're talking about could be useful during the very first steps of learning a new language.
But soon, you will be able to cope with larger chunks of code, perceiving patterns and idiomatic uses of Perl. A software that understands the meaning of even 4-5 lines of code could be a huge effort: understanding semantics is complex in artificial languages such as in natural languages.
By the way, Perl has many syntax constructs that are difficult to read even for experienced programmers: for example, regular expressions.
In this case, tools like this are very useful :)
