REPL vs CLI: IDE wars(vlaaad.github.io)

    $ sbcl
    This is SBCL 2.1.1.52.HEAD.321-f8a57bcca, an         
    implementation of ANSI Common Lisp.
    More information about SBCL is available at 
    <http://www.sbcl.org/>.

    SBCL is free software, provided as is, with absolutely no warranty.
    It is mostly in the public domain; some portions are provided under
    BSD-style licenses.  See the CREDITS and COPYING files in the
    distribution for more information.
    \* (\* x x)

    debugger invoked on a UNBOUND-VARIABLE in thread
    #<THREAD "main thread" RUNNING {1001860103}>:
      The variable X is unbound.

    Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

    restarts (invokable by number or by possibly-abbreviated name):
      0: [CONTINUE   ] Retry using X.
      1: [USE-VALUE  ] Use specified value.
      2: [STORE-VALUE] Set specified value and use it.
      3: [ABORT      ] Exit debugger, returning to top level.

    (SB-INT:SIMPLE-EVAL-IN-LEXENV X #<NULL-LEXENV>)

    Enter a form to be evaluated: 3
    9
    \*

    An error occurred on ./test:18
    Frame 1 (./test:21)
    18           false
    19       }
    20
    21   >>> a

    Frame 2 (./test:6)
    3        source TRAPERR.zsh
    4
    5        a() {
    6    >>>     b
    7        }
    8
    9        b() {

    Frame 3 (./test:10)
    7        }
    8
    9        b() {
    10   >>>     c
    11       }
    12
    13       c() {

    Frame 4 (./test:14)
    11       }
    12
    13       c() {
    14   >>>     d
    15       }
    16
    17       d() {

    Frame 5 (./test:18)
    15       }
    16
    17       d() {
    18   >>>     false
    19       }
    20
    21       a