(do ;;; Simple BF interpreter, based on the Lua sample: "Simple meta-implementation using load"
    ;;;                       reads the BF code from stdin, builds an equivalent Pluto program and executes it

    (local bf-op { ">" "ptr = ptr + 1"
                   "<" "ptr = ptr - 1"
                   "+" "mem[ptr] = mem[ptr] + 1"
                   "-" "mem[ptr] = mem[ptr] - 1"
                   "[" "while mem[ptr] ~= 0 do"
                   "]" "end"
                   "." "io.write(string.char(mem[ptr]))"
                   "," "mem[ptr] = string.byte(io.read(1) or \"\\0\")"
                 }
    )

    (var bf-program (.. "local mem = setmetatable({}, { __index = function() return 0 end })\n"
                        "local ptr = 1\n"
                    )
    )
    (each [line (io.lines)]
          (for [p 1 (length line)]
               (local op (. bf-op (line:sub p p)))
               (when op
                     (set bf-program (.. bf-program op "\n"))
               )
          )
    )
    (local (bf-code msg) (load bf-program))
    (if bf-code
        (bf-code)
    ;else
        (error msg)
    )

)