repl

Generic, reusable, read-eval-print loop. By default, reads from *in*,
writes to *out*, and prints exception summaries to *err*. If you use the
default :read hook, *in* must either be an instance of
LineNumberingPushbackReader or duplicate its behavior of both supporting
.unread and collapsing CR, LF, and CRLF into a single \newline. Options
are sequential keyword-value pairs. Available options and their defaults:
    - :init, function of no arguments, initialization hook called with
     bindings for set!-able vars in place.
     default: #()
    - :need-prompt, function of no arguments, called before each
     read-eval-print except the first, the user will be prompted if it
     returns true.
     default: (if (instance? LineNumberingPushbackReader *in*)
                #(.atLineStart *in*)
                #(identity true))
    - :prompt, function of no arguments, prompts for more input.
     default: repl-prompt
    - :flush, function of no arguments, flushes output
     default: flush
    - :read, function of two arguments, reads from *in*:
       - returns its first argument to request a fresh prompt
         - depending on need-prompt, this may cause the repl to prompt
           before reading again
       - returns its second argument to request an exit from the repl
       - else returns the next object read from the input stream
     default: repl-read
    - :eval, function of one argument, returns the evaluation of its
     argument
     default: eval
    - :print, function of one argument, prints its argument to the output
     default: prn
    - :caught, function of one argument, a throwable, called when
     read, eval, or print throws an exception or error
     default: repl-caught