[dllthomas]

Translating naively, in Haskell I might use https://hackage.haskell.org/package/containers-0.6.5.1/docs/..., which does use sharing to reduce copying.

[tromp]

A simple Brankfuck interpreter in Haskell using state monads may be found at https://tromp.github.io/cl/Binary_lambda_calculus.html#Brain...

[dllthomas]

Yeah, for something where changes are local like that, using two stacks for your tape makes a lot of sense.