bf2c.hs

main = putStrLn prelude
    >> interact (unlines . filter (not . null) . map compile)
    >> putStrLn afterward

a +++ b     = a ++ "\n" ++ b
prelude     = "#include <stdio.h>"
          +++ "char b[1000000];"
          +++ "int main() {"
          +++ "char* p = b;"
compile '>' = "p++;"
compile '<' = "p--;"
compile '[' = "while (*p) {"
compile ']' = "}"
compile ',' = "(*p) = getchar(); if (*p == EOF) { return 0; }"
compile '.' = "putchar(*p);"
compile '+' = "(*p)++;"
compile '-' = "(*p)--;"
compile _   = ""
afterward   = "}"
          +++ "// lol"