Can pure expression be reduced/inlined and optimized at compile time?

[milesfrain]

Evaluation at compile time might also be a good way to eliminate unsafePartial in some situations.

Compile-time checks for Regular Expressions

Could regular expressions be checked at compile time, rather than relying on unsafePartial when calling regex? It’s a bummer to instruct readers to write “unsafe” code in Ch7 of the book, and likewise tedious to account for the Left error during runtime. Is something like C++`s constexpr available?