Sure. Total functional programming (provably terminating code) comes at the cost of Turing-completeness. The choice exists. https://en.wikipedia.org/wiki/Tota

Sure. Total functional programming (provably terminating code) comes at the cost of Turing-completeness. The choice exists. https://en.wikipedia.org/wiki/Total_functional_programming https://en.wikipedia.org/wiki/Total_functional_programming Observe though that BNF is just a notation. Parsers for BNF are not implemented in BNF. Bison. Yacc.