Check out Ur/Web[1].
It's a functional, pure and statically typed language inspired by Haskell. It claims that programs that compile successfully cannot:
- Suffer from any kinds of code-injection attacks
- Return invalid HTML
- Contain dead intra-application links
- Have mismatches between HTML forms and the fields expected by their handlers
- Include client-side code that makes incorrect assumptions about the "AJAX"-style services that the remote web server provides
- Attempt invalid SQL queries
- Use improper marshaling or unmarshaling in communication with SQL databases or between