M lib/utils.hex → lib/utils.hex

@@ -72,9 +72,23 @@ "_ends_c"      #
   "_ends_offset" #
 ) "ends" ::
 
+;;; when
+;; q1 q2 -> *
+;; If %:q1%% pushes 0x1 on the stack, dequotes %:q2%%.
+(
+  "_when_q"    :
+  "_when_cond" :
+  (_when_cond .)
+    (_when_q .)
+    ()
+  if
+  "_when_q"    #
+  "_when_cond" #
+) "when" ::
+
 ;;; cleanup
 ;; s ->
-;; Frees all symbols starting %:s%%.
+;; Frees all symbols starting with %:s%%.
 (
   "_cleanup_prefix" :
   0x0 "_cleanup_c" :

M web/contents/learn.html → web/contents/learn.html

@@ -35,7 +35,7 @@ <p>Instead, it focuses on making do with just a few things, or better, <em>data types</em>.</p>
     <p>It understands <strong>integers</strong> like 27 or -19, except that if you type any of those in the REPL (go on,
         <a href="/play">try it</a>!) and press ENTER, you'll get something like this:
     </p>
-    <pre><code>[error] Invalid symbol: 27</code></pre>
+    <pre><code>ERROR: Invalid symbol: 27</code></pre>
     <p>Right, because <em>hex</em> only understands integers in hexadecimal format. </p>
     <p>Now, if you type <code>$0x1b$$</code> instead... well, at least it doesn't complain, right? You can try
         entering <code>$0xffffffed$$</code> now (that's -19 in hexadecimal format using <a