2004-07-01-two-way-analogy-of-bpel-as-ws-assembler.html

---
layout: post
title: "Two-Way Analogy of BPEL as WS-Assembler"
permalink: two-way-analogy-of-bpel-as-ws-assembler.html
categories: [bpel, assembly, appleii]
---
<p>On the one hand, calling BPEL "WS-Assembler" as a language for assembling existing web services into new web services seems reasonable enough, but there is another low-level analogy that is equally apt and sure to warm the hearts of people who started programming in the late 1970s and early 1980s:</p>

<table>
<tr>
<th>Assembly Language</th>
<th>BPEL</th>
</tr>
<tr>
<td>registers</td>
<td>communication channels</td>
</tr>
<tr>
<td>bytes/bits</td>
<td>messages/parts</td>
</tr>
<tr>
<td>memory</td>
<td>variables</td>
</tr>
<tr>
<td>operations on bytes/bits/memory</td>
<td>operations on messages/parts/variables</td>
</tr>
<tr>
<td>CPU</td>
<td>BPEL engine</td>
</tr>
</table>

<p>The assembly language aesthetic for BPEL is opposite and complementary to the aesthetics for approaching BPEL through GUI tools, long-lived programming language concurrency annotations, or draw-your-program front-ends. (As an aside, I always had a hard time thinking of "Merlin" as <a href="http://www.javaworld.com/javaworld/jw-03-2001/jw-0316-jdk.html">JDK 1.4</a> instead of the Apple ][ <a href="http://apple2.org.za/gswv/a2zine/Utils/MerlinAssembler/Info_MERLINfiles.txt">macro assember</a>...)</p>