Such an environment would most likely be based on Haskell, if not something more esoteric.

Assuming performance is a concern, Haskell probably strikes the best balance between crazy-powerful type systems and compiler maturity.

As an anecdote, the exact string-escape issue you've mentioned is a (repeatedly) solved problem in that ecosystem, the type system being clever enough to escape most of the verbosity and non-genericity you'd get by trying the same thing in, say, C.