David Wheeler wrote the following about sloccount.  This is excerpted from
a much longer TODO with many issues that have been solved by the Go port.

Obviously, a general "TODO" is adding support for other computer languages;
here are languages I'd like to add support for specifically:
+ .pco -> Oracle preprocessed Cobol Code
+ .pfo -> Oracle preprocessed Fortran Code
+ Improve Ocamlyacc, comments in yacc part are C-like, but I'm not sure
  about comment nesting. 

Here are other TODOs:

* Handle scripts embedded in data.
  Perhaps create a category, "only the code embedded in HTML"
  (e.g., Javascript scripts, PHP statements, etc.).
  This is currently complicated - the whole program assumes that a file
  can be assigned a specific type, and HTML (etc.) might have multiple
  languages embedded in it.

* Improve makefile identification and counting.
  Currently the makefiles count "all non-blank lines"; conceivably
  someone might want to count only the actual directives, not the
  conditions under which they fire.
  Need to handle ".rules" too.

TODO items specific to the Go implementation start here:

* How to weight EAF: https://dwheeler.com/sloccount/sloccount.html#cocomo

* Detect inline assembler in C?  https://en.wikipedia.org/wiki/Inline_assembler
  Could implent an asm quirk for C and Rust?