Lisp and Haskell (2017)
So I put his example into a lisp file and compiled it under SLIME&#x2F;sbcl, which is how I typically develop:<p><pre><code>    1 compiler notes:

    scratch.lisp:10:7:                                                                                                                  
      warning:                                                                                                                           
        The function (LAMBDA (X) :IN ADD-TEXT-PADDING) called by MAP-INTO returns NULL but CHARACTER is expected                           
        See also:                                                                                                                          
          SBCL Manual, Handling of Types [:node]                                                                                             
        --&gt; TRULY-THE SB-KERNEL:%MAP                                                                                                       
        ==&gt;                                                                                                                                
          (MAP-INTO (MAKE-SEQUENCE SB-C::RESULT-TYPE (MIN (LENGTH #:G51))) SB-C::FUN                                                         
                    #:G51)                                                                                                                             
                                                                                                                                         

    Compilation failed.
</code></pre>
It&#x27;s also patently false that quicklisp has no tests; it has no unit tests, but it is tested as a whole thoroughly, both the code <i>and</i> the set of systems it provides.