Pastable version of Group-by

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            <pre class="sunburst"><span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>; Turns a flat-list into a list of n-sized lists</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>; Examples:</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>;   (group-by '(1 2 3 4) 2) =&gt; ((1 2) (3 4))</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>;   (group-by '(a b c d) 3) =&gt; ((a b c) (d))</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>;   (group-by '(a b c d) 1) =&gt; ((a) (b) (c) (d))</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>;   (group-by '(a b c d) 4) =&gt; ((a b c d))</span>
<span style="color:#AEAEAE;font-style:italic;"><span style="color:#AEAEAE;font-style:italic;">;</span>;   (group-by '(a b c d e f 1 2 3 4 5 6) 7) =&gt; (a b c d e f 1) (2 3 4 5 6))</span>

(define (group-by x n)
  (<span style="color:#E28964;">let</span> <span style="color:#E28964;">loop</span> ((x x) (grouped '()) (current '()) (i <span style="color:#3387CC;">0</span>))
    (<span style="color:#E28964;">if</span> (<span style="color:#3387CC;">null</span>? x)
	(reverse (<span style="color:#DAD085;">cons</span> (reverse current) grouped))
	(<span style="color:#E28964;">if</span> (= i n)
	    (<span style="color:#E28964;">loop</span> x (<span style="color:#DAD085;">cons</span> (reverse current) grouped) '() <span style="color:#3387CC;">0</span>)
	    (<span style="color:#E28964;">loop</span> (<span style="color:#DAD085;">cdr</span> x) grouped (<span style="color:#DAD085;">cons</span> (<span style="color:#DAD085;">car</span> x) current) (+ i <span style="color:#3387CC;">1</span>))))))
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