I believe lots of people used FP to write short and correct programs; then they profile and tweak the bits that needs it.
Also, are you using javascript native .map method ? IIRC libraries like lodash or ramda, through use of reducers, have vastly faster idiomatic FP performance. Mostly because they avoid successive array allocation.
Also, are you using javascript native .map method ? IIRC libraries like lodash or ramda, through use of reducers, have vastly faster idiomatic FP performance. Mostly because they avoid successive array allocation.