summaryrefslogtreecommitdiff
path: root/gemfeed/2010-04-09-standard-ml-and-haskell.html
diff options
context:
space:
mode:
Diffstat (limited to 'gemfeed/2010-04-09-standard-ml-and-haskell.html')
-rw-r--r--gemfeed/2010-04-09-standard-ml-and-haskell.html181
1 files changed, 88 insertions, 93 deletions
diff --git a/gemfeed/2010-04-09-standard-ml-and-haskell.html b/gemfeed/2010-04-09-standard-ml-and-haskell.html
index e098b9a4..7fc14e02 100644
--- a/gemfeed/2010-04-09-standard-ml-and-haskell.html
+++ b/gemfeed/2010-04-09-standard-ml-and-haskell.html
@@ -2,17 +2,12 @@
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
-<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Standard ML and Haskell</title>
<link rel="shortcut icon" type="image/gif" href="/favicon.ico" />
<link rel="stylesheet" href="../style.css" />
<link rel="stylesheet" href="style-override.css" />
</head>
<body>
-<div class="rfx-overlay-grid"></div>
-<div class="rfx-overlay-scanlines"></div>
-<div id="rfx-stars"></div>
-<div class="rfx-vignette"></div>
<p class="header">
<a href="https://foo.zone">Home</a> | <a href="https://codeberg.org/snonux/foo.zone/src/branch/content-md/gemfeed/2010-04-09-standard-ml-and-haskell.md">Markdown</a> | <a href="gemini://foo.zone/gemfeed/2010-04-09-standard-ml-and-haskell.gmi">Gemini</a>
</p>
@@ -45,10 +40,10 @@
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">datatype</font></b><font color="#ff0000"> ’a multi</font>
-<font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> EMPTY</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> ELEM </font><b><font color="#ffffff">of</font></b><font color="#ff0000"> ’a</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> UNION </font><b><font color="#ffffff">of</font></b><font color="#ff0000"> ’a multi </font><font color="#F3E651">*</font><font color="#ff0000"> ’a multi</font>
+<pre><b><u><font color="#000000">datatype</font></u></b> ’a multi
+ = EMPTY
+ | ELEM <b><u><font color="#000000">of</font></u></b> ’a
+ | UNION <b><u><font color="#000000">of</font></u></b> ’a multi * ’a multi
</pre>
<br />
<span>Haskell:</span><br />
@@ -57,11 +52,11 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">data</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Eq</font></b><font color="#ff0000"> a</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=&gt;</font><font color="#ff0000"> </font><b><font color="#F35E1E">Multi</font></b><font color="#ff0000"> a</font>
-<font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">Empty</font></b>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> </font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> a</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> </font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Multi</font></b><font color="#ff0000"> a</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Multi</font></b><font color="#ff0000"> a</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">deriving</font></b><font color="#ff0000"> </font><b><font color="#F35E1E">Show</font></b>
+<pre><b><u><font color="#000000">data</font></u></b> (<b><font color="#000000">Eq</font></b> a) =&gt; <b><font color="#000000">Multi</font></b> a
+ = <b><font color="#000000">Empty</font></b>
+ | <b><font color="#000000">Elem</font></b> a
+ | <b><font color="#000000">Union</font></b> (<b><font color="#000000">Multi</font></b> a) (<b><font color="#000000">Multi</font></b> a)
+ <b><u><font color="#000000">deriving</font></u></b> <b><font color="#000000">Show</font></b>
</pre>
<br />
<h2 style='display: inline' id='processing-a-multi'>Processing a multi</h2><br />
@@ -72,12 +67,12 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">fun</font></b><font color="#ff0000"> number </font><font color="#F3E651">(</font><font color="#ff0000">EMPTY</font><font color="#F3E651">)</font><font color="#ff0000"> _ </font><font color="#F3E651">=</font><font color="#ff0000"> </font><font color="#bb00ff">0</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> number </font><font color="#F3E651">(</font><font color="#ff0000">ELEM x</font><font color="#F3E651">)</font><font color="#ff0000"> w </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">=</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#bb00ff">1</font><font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><font color="#bb00ff">0</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> number </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000">y</font><font color="#F3E651">))</font><font color="#ff0000"> w </font><font color="#F3E651">=</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">number x w</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">+</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">number y w</font><font color="#F3E651">)</font>
-<b><font color="#ffffff">fun</font></b><font color="#ff0000"> test_number w </font><font color="#F3E651">=</font><font color="#ff0000"> number </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">EMPTY</font><font color="#F3E651">,</font><font color="#ff0000"> </font><font color="#F3E651">\</font>
-<font color="#ff0000"> UNION </font><font color="#F3E651">(</font><font color="#ff0000">ELEM </font><font color="#bb00ff">4</font><font color="#F3E651">,</font><font color="#ff0000"> UNION </font><font color="#F3E651">(</font><font color="#ff0000">ELEM </font><font color="#bb00ff">6</font><font color="#F3E651">,</font><font color="#ff0000"> </font><font color="#F3E651">\</font>
-<font color="#ff0000"> UNION </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">ELEM </font><font color="#bb00ff">4</font><font color="#F3E651">,</font><font color="#ff0000"> ELEM </font><font color="#bb00ff">4</font><font color="#F3E651">),</font><font color="#ff0000"> EMPTY</font><font color="#F3E651">)))))</font><font color="#ff0000"> w </font>
+<pre><b><u><font color="#000000">fun</font></u></b> number (EMPTY) _ = <font color="#000000">0</font>
+ | number (ELEM x) w = <b><u><font color="#000000">if</font></u></b> x = w <b><u><font color="#000000">then</font></u></b> <font color="#000000">1</font> <b><u><font color="#000000">else</font></u></b> <font color="#000000">0</font>
+ | number (UNION (x,y)) w = (number x w) + (number y w)
+<b><u><font color="#000000">fun</font></u></b> test_number w = number (UNION (EMPTY, \
+ UNION (ELEM <font color="#000000">4</font>, UNION (ELEM <font color="#000000">6</font>, \
+ UNION (UNION (ELEM <font color="#000000">4</font>, ELEM <font color="#000000">4</font>), EMPTY))))) w
</pre>
<br />
<span>Haskell:</span><br />
@@ -86,11 +81,11 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><font color="#ff0000">number </font><b><font color="#F35E1E">Empty</font></b><font color="#ff0000"> </font><b><font color="#ffffff">_</font></b><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><font color="#bb00ff">0</font>
-<font color="#ff0000">number </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> x</font><font color="#F3E651">)</font><font color="#ff0000"> w </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">==</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#bb00ff">1</font><font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><font color="#bb00ff">0</font>
-<font color="#ff0000">test_number w </font><font color="#F3E651">=</font><font color="#ff0000"> number </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><b><font color="#F35E1E">Empty</font></b><font color="#ff0000"> </font><font color="#F3E651">\</font>
-<font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> </font><font color="#bb00ff">4</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> </font><font color="#bb00ff">6</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">\</font>
-<font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> </font><font color="#bb00ff">4</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> </font><font color="#bb00ff">4</font><font color="#F3E651">))</font><font color="#ff0000"> </font><b><font color="#F35E1E">Empty</font></b><font color="#F3E651">))))</font><font color="#ff0000"> w</font>
+<pre>number <b><font color="#000000">Empty</font></b> <b><u><font color="#000000">_</font></u></b> = <font color="#000000">0</font>
+number (<b><font color="#000000">Elem</font></b> x) w = <b><u><font color="#000000">if</font></u></b> x == w <b><u><font color="#000000">then</font></u></b> <font color="#000000">1</font> <b><u><font color="#000000">else</font></u></b> <font color="#000000">0</font>
+test_number w = number (<b><font color="#000000">Union</font></b> <b><font color="#000000">Empty</font></b> \
+ (<b><font color="#000000">Union</font></b> (<b><font color="#000000">Elem</font></b> <font color="#000000">4</font>) (<b><font color="#000000">Union</font></b> (<b><font color="#000000">Elem</font></b> <font color="#000000">6</font>) \
+ (<b><font color="#000000">Union</font></b> (<b><font color="#000000">Union</font></b> (<b><font color="#000000">Elem</font></b> <font color="#000000">4</font>) (<b><font color="#000000">Elem</font></b> <font color="#000000">4</font>)) <b><font color="#000000">Empty</font></b>)))) w
</pre>
<br />
<h2 style='display: inline' id='simplify-function'>Simplify function</h2><br />
@@ -101,19 +96,19 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">fun</font></b><font color="#ff0000"> simplify </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000">y</font><font color="#F3E651">))</font><font color="#ff0000"> </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><b><font color="#ffffff">fun</font></b><font color="#ff0000"> is_empty </font><font color="#F3E651">(</font><font color="#ff0000">EMPTY</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> true </font><font color="#F3E651">|</font><font color="#ff0000"> is_empty _ </font><font color="#F3E651">=</font><font color="#ff0000"> false</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">val</font></b><font color="#ff0000"> x’ </font><font color="#F3E651">=</font><font color="#ff0000"> simplify x</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">val</font></b><font color="#ff0000"> y’ </font><font color="#F3E651">=</font><font color="#ff0000"> simplify y</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">is_empty x’</font><font color="#F3E651">)</font><font color="#ff0000"> </font><b><font color="#ffffff">andalso</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">is_empty y’</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> EMPTY</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">is_empty x’</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> y’</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">is_empty y’</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> x’</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> UNION </font><font color="#F3E651">(</font><font color="#ff0000">x’</font><font color="#F3E651">,</font><font color="#ff0000"> y’</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">end</font></b>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> simplify x </font><font color="#F3E651">=</font><font color="#ff0000"> x</font>
+<pre><b><u><font color="#000000">fun</font></u></b> simplify (UNION (x,y)) =
+ <b><u><font color="#000000">let</font></u></b> <b><u><font color="#000000">fun</font></u></b> is_empty (EMPTY) = true | is_empty _ = false
+ <b><u><font color="#000000">val</font></u></b> x’ = simplify x
+ <b><u><font color="#000000">val</font></u></b> y’ = simplify y
+ <b><u><font color="#000000">in</font></u></b> <b><u><font color="#000000">if</font></u></b> (is_empty x’) <b><u><font color="#000000">andalso</font></u></b> (is_empty y’)
+ <b><u><font color="#000000">then</font></u></b> EMPTY
+ <b><u><font color="#000000">else</font></u></b> <b><u><font color="#000000">if</font></u></b> (is_empty x’)
+ <b><u><font color="#000000">then</font></u></b> y’
+ <b><u><font color="#000000">else</font></u></b> <b><u><font color="#000000">if</font></u></b> (is_empty y’)
+ <b><u><font color="#000000">then</font></u></b> x’
+ <b><u><font color="#000000">else</font></u></b> UNION (x’, y’)
+ <b><u><font color="#000000">end</font></u></b>
+ | simplify x = x
</pre>
<br />
<span>Haskell:</span><br />
@@ -122,17 +117,17 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><font color="#ff0000">simplify </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x y</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">isEmpty x’</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">&amp;&amp;</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">isEmpty y’</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">Empty</font></b>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> isEmpty x’ </font><font color="#F3E651">=</font><font color="#ff0000"> y’</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> isEmpty y’ </font><font color="#F3E651">=</font><font color="#ff0000"> x’</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> otherwise </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x’ y’</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">where</font></b>
-<font color="#ff0000"> isEmpty </font><b><font color="#F35E1E">Empty</font></b><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">True</font></b>
-<font color="#ff0000"> isEmpty </font><b><font color="#ffffff">_</font></b><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">False</font></b>
-<font color="#ff0000"> x’ </font><font color="#F3E651">=</font><font color="#ff0000"> simplify x</font>
-<font color="#ff0000"> y’ </font><font color="#F3E651">=</font><font color="#ff0000"> simplify y</font>
-<font color="#ff0000">simplify x </font><font color="#F3E651">=</font><font color="#ff0000"> x</font>
+<pre>simplify (<b><font color="#000000">Union</font></b> x y)
+ | (isEmpty x’) &amp;&amp; (isEmpty y’) = <b><font color="#000000">Empty</font></b>
+ | isEmpty x’ = y’
+ | isEmpty y’ = x’
+ | otherwise = <b><font color="#000000">Union</font></b> x’ y’
+ <b><u><font color="#000000">where</font></u></b>
+ isEmpty <b><font color="#000000">Empty</font></b> = <b><font color="#000000">True</font></b>
+ isEmpty <b><u><font color="#000000">_</font></u></b> = <b><font color="#000000">False</font></b>
+ x’ = simplify x
+ y’ = simplify y
+simplify x = x
</pre>
<br />
<h2 style='display: inline' id='delete-all'>Delete all</h2><br />
@@ -143,12 +138,12 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">fun</font></b><font color="#ff0000"> delete_all m w </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><b><font color="#ffffff">fun</font></b><font color="#ff0000"> delete_all’ </font><font color="#F3E651">(</font><font color="#ff0000">ELEM x</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">=</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> EMPTY </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> ELEM x</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> delete_all’ </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000">y</font><font color="#F3E651">))</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> UNION </font><font color="#F3E651">(</font><font color="#ff0000">delete_all’ x</font><font color="#F3E651">,</font><font color="#ff0000"> delete_all’ y</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> delete_all’ x </font><font color="#F3E651">=</font><font color="#ff0000"> x</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> simplify </font><font color="#F3E651">(</font><font color="#ff0000">delete_all’ m</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">end</font></b>
+<pre><b><u><font color="#000000">fun</font></u></b> delete_all m w =
+ <b><u><font color="#000000">let</font></u></b> <b><u><font color="#000000">fun</font></u></b> delete_all’ (ELEM x) = <b><u><font color="#000000">if</font></u></b> x = w <b><u><font color="#000000">then</font></u></b> EMPTY <b><u><font color="#000000">else</font></u></b> ELEM x
+ | delete_all’ (UNION (x,y)) = UNION (delete_all’ x, delete_all’ y)
+ | delete_all’ x = x
+ <b><u><font color="#000000">in</font></u></b> simplify (delete_all’ m)
+ <b><u><font color="#000000">end</font></u></b>
</pre>
<br />
<span>Haskell:</span><br />
@@ -157,11 +152,11 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><font color="#ff0000">delete_all m w </font><font color="#F3E651">=</font><font color="#ff0000"> simplify </font><font color="#F3E651">(</font><font color="#ff0000">delete_all’ m</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">where</font></b>
-<font color="#ff0000"> delete_all’ </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> x</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">==</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><b><font color="#F35E1E">Empty</font></b><font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> x</font>
-<font color="#ff0000"> delete_all’ </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x y</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">delete_all’ x</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">delete_all’ y</font><font color="#F3E651">)</font>
-<font color="#ff0000"> delete_all’ x </font><font color="#F3E651">=</font><font color="#ff0000"> x</font>
+<pre>delete_all m w = simplify (delete_all’ m)
+ <b><u><font color="#000000">where</font></u></b>
+ delete_all’ (<b><font color="#000000">Elem</font></b> x) = <b><u><font color="#000000">if</font></u></b> x == w <b><u><font color="#000000">then</font></u></b> <b><font color="#000000">Empty</font></b> <b><u><font color="#000000">else</font></u></b> <b><font color="#000000">Elem</font></b> x
+ delete_all’ (<b><font color="#000000">Union</font></b> x y) = <b><font color="#000000">Union</font></b> (delete_all’ x) (delete_all’ y)
+ delete_all’ x = x
</pre>
<br />
<h2 style='display: inline' id='delete-one'>Delete one</h2><br />
@@ -172,21 +167,21 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><b><font color="#ffffff">fun</font></b><font color="#ff0000"> delete_one m w </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><b><font color="#ffffff">fun</font></b><font color="#ff0000"> delete_one’ </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000">y</font><font color="#F3E651">))</font><font color="#ff0000"> </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><b><font color="#ffffff">val</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">x’</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ x</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> deleted</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x’</font><font color="#F3E651">,</font><font color="#ff0000"> y</font><font color="#F3E651">),</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><b><font color="#ffffff">val</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">y’</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ y</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">UNION </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000"> y’</font><font color="#F3E651">),</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">end</font></b>
-<font color="#ff0000"> </font><b><font color="#ffffff">end</font></b>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> delete_one’ </font><font color="#F3E651">(</font><font color="#ff0000">ELEM x</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">=</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">EMPTY</font><font color="#F3E651">,</font><font color="#ff0000"> true</font><font color="#F3E651">)</font><font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">ELEM x</font><font color="#F3E651">,</font><font color="#ff0000"> false</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><font color="#F3E651">|</font><font color="#ff0000"> delete_one’ x </font><font color="#F3E651">=</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000"> false</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">val</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">m’</font><font color="#F3E651">,</font><font color="#ff0000"> _</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ m</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> simplify m’</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">end</font></b>
+<pre><b><u><font color="#000000">fun</font></u></b> delete_one m w =
+ <b><u><font color="#000000">let</font></u></b> <b><u><font color="#000000">fun</font></u></b> delete_one’ (UNION (x,y)) =
+ <b><u><font color="#000000">let</font></u></b> <b><u><font color="#000000">val</font></u></b> (x’, deleted) = delete_one’ x
+ <b><u><font color="#000000">in</font></u></b> <b><u><font color="#000000">if</font></u></b> deleted
+ <b><u><font color="#000000">then</font></u></b> (UNION (x’, y), deleted)
+ <b><u><font color="#000000">else</font></u></b> <b><u><font color="#000000">let</font></u></b> <b><u><font color="#000000">val</font></u></b> (y’, deleted) = delete_one’ y
+ <b><u><font color="#000000">in</font></u></b> (UNION (x, y’), deleted)
+ <b><u><font color="#000000">end</font></u></b>
+ <b><u><font color="#000000">end</font></u></b>
+ | delete_one’ (ELEM x) =
+ <b><u><font color="#000000">if</font></u></b> x = w <b><u><font color="#000000">then</font></u></b> (EMPTY, true) <b><u><font color="#000000">else</font></u></b> (ELEM x, false)
+ | delete_one’ x = (x, false)
+ <b><u><font color="#000000">val</font></u></b> (m’, _) = delete_one’ m
+ <b><u><font color="#000000">in</font></u></b> simplify m’
+ <b><u><font color="#000000">end</font></u></b>
</pre>
<br />
<span>Haskell:</span><br />
@@ -195,19 +190,19 @@ http://www.gnu.org/software/src-highlite -->
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
-<pre><font color="#ff0000">delete_one m w </font><font color="#F3E651">=</font><font color="#ff0000"> </font><b><font color="#ffffff">do</font></b>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">m’</font><font color="#F3E651">,</font><font color="#ff0000"> </font><b><font color="#ffffff">_</font></b><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ m</font>
-<font color="#ff0000"> simplify m’</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">where</font></b>
-<font color="#ff0000"> delete_one’ </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x y</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">x’</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ x</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> deleted</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x’ y</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><b><font color="#ffffff">let</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">y’</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font><font color="#ff0000"> delete_one’ y</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">in</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Union</font></b><font color="#ff0000"> x y’</font><font color="#F3E651">,</font><font color="#ff0000"> deleted</font><font color="#F3E651">)</font>
-<font color="#ff0000"> delete_one’ </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> x</font><font color="#F3E651">)</font><font color="#ff0000"> </font><font color="#F3E651">=</font>
-<font color="#ff0000"> </font><b><font color="#ffffff">if</font></b><font color="#ff0000"> x </font><font color="#F3E651">==</font><font color="#ff0000"> w </font><b><font color="#ffffff">then</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Empty</font></b><font color="#F3E651">,</font><font color="#ff0000"> </font><b><font color="#F35E1E">True</font></b><font color="#F3E651">)</font><font color="#ff0000"> </font><b><font color="#ffffff">else</font></b><font color="#ff0000"> </font><font color="#F3E651">(</font><b><font color="#F35E1E">Elem</font></b><font color="#ff0000"> x</font><font color="#F3E651">,</font><font color="#ff0000"> </font><b><font color="#F35E1E">False</font></b><font color="#F3E651">)</font>
-<font color="#ff0000"> delete_one’ x </font><font color="#F3E651">=</font><font color="#ff0000"> </font><font color="#F3E651">(</font><font color="#ff0000">x</font><font color="#F3E651">,</font><font color="#ff0000"> </font><b><font color="#F35E1E">False</font></b><font color="#F3E651">)</font>
+<pre>delete_one m w = <b><u><font color="#000000">do</font></u></b>
+ <b><u><font color="#000000">let</font></u></b> (m’, <b><u><font color="#000000">_</font></u></b>) = delete_one’ m
+ simplify m’
+ <b><u><font color="#000000">where</font></u></b>
+ delete_one’ (<b><font color="#000000">Union</font></b> x y) =
+ <b><u><font color="#000000">let</font></u></b> (x’, deleted) = delete_one’ x
+ <b><u><font color="#000000">in</font></u></b> <b><u><font color="#000000">if</font></u></b> deleted
+ <b><u><font color="#000000">then</font></u></b> (<b><font color="#000000">Union</font></b> x’ y, deleted)
+ <b><u><font color="#000000">else</font></u></b> <b><u><font color="#000000">let</font></u></b> (y’, deleted) = delete_one’ y
+ <b><u><font color="#000000">in</font></u></b> (<b><font color="#000000">Union</font></b> x y’, deleted)
+ delete_one’ (<b><font color="#000000">Elem</font></b> x) =
+ <b><u><font color="#000000">if</font></u></b> x == w <b><u><font color="#000000">then</font></u></b> (<b><font color="#000000">Empty</font></b>, <b><font color="#000000">True</font></b>) <b><u><font color="#000000">else</font></u></b> (<b><font color="#000000">Elem</font></b> x, <b><font color="#000000">False</font></b>)
+ delete_one’ x = (x, <b><font color="#000000">False</font></b>)
</pre>
<br />
<h2 style='display: inline' id='higher-order-functions'>Higher-order functions</h2><br />
@@ -232,11 +227,11 @@ my_filter f l = foldr (make_filter_fn f) [] l
<br />
<a class='textlink' href='../'>Back to the main site</a><br />
<p class="footer">
- Generated with <a href="https://codeberg.org/snonux/gemtexter">Gemtexter 3.0.1-develop</a> |
- served by <a href="https://www.OpenBSD.org">OpenBSD</a>/<a href="https://man.openbsd.org/relayd.8">relayd(8)</a>+<a href="https://man.openbsd.org/httpd.8">httpd(8)</a> |
- <a href="https://foo.zone/site-mirrors.html">Site Mirrors</a>
- <br />
- Webring: <a href="https://shring.sh/foo.zone/previous">previous</a> | <a href="https://shring.sh">shring</a> | <a href="https://shring.sh/foo.zone/next">next</a>
+ Generated with <a href="https://codeberg.org/snonux/gemtexter">Gemtexter 3.0.1-develop</a> |
+ served by <a href="https://www.OpenBSD.org">OpenBSD</a>/<a href="https://man.openbsd.org/relayd.8">relayd(8)</a>+<a href="https://man.openbsd.org/httpd.8">httpd(8)</a> |
+ <a href="https://foo.zone/site-mirrors.html">Site Mirrors</a>
+ <br />
+ Webring: <a href="https://shring.sh/foo.zone/previous">previous</a> | <a href="https://shring.sh">shring</a> | <a href="https://shring.sh/foo.zone/next">next</a>
</p>
</body>
</html>
generated by cgit v1.2.3 (git 2.25.1) at 2026-04-17 17:37:29 +0000