From 4e7fdd57cbf8f60f674ba48fd04c80ad59a20579 Mon Sep 17 00:00:00 2001
From: Jed Barber <jjbarber@y7mail.com>
Date: Sun, 1 Jan 2017 15:00:53 +1100
Subject: Base template tweaked, old Grasp/Thue articles added from previous
 website efforts

---
 project/templates/grasp.html | 70 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 project/templates/grasp.html

(limited to 'project/templates/grasp.html')

diff --git a/project/templates/grasp.html b/project/templates/grasp.html
new file mode 100644
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--- /dev/null
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+
+{% extends "base.html" %}
+
+
+
+{% block title %}Grasp Interpreter{% endblock %}
+
+
+
+{% block content %}
+
+<h4>Grasp Interpreter</h4>
+
+<p>Like Lisp, the esoteric programming language <a href="http://esolangs.org/wiki/Grasp">Grasp</a>
+is a homoiconic language that exclusively uses a single datatype. Except instead of lists, it uses
+directed graphs.</p>
+
+<p>A Grasp program is initialised with instruction pointers to those nodes in the graph that have
+a "name" edge to a node with the value "grasp:main". The nodes at each instruction pointer are
+evaluated and the pointer then updated by following an available "next" edge. This continues until
+all instruction pointers have no more "next" edges to follow.</p>
+
+<figure>
+    <img src="/img/grasp_helloworld.png"
+         alt="Hello World in Grasp"
+         height="176"
+         width="268">
+    <figcaption>Hello World in Grasp</figcaption>
+</figure>
+
+<p>In the <a href="https://github.com/fis/grajsp/wiki/Grasp-specification">current specification</a>,
+the actions that can be performed are:</p>
+
+<ul>
+    <li>add or delete an edge</li>
+    <li>change the value of a node</li>
+    <li>add, subtract, multiply, divide, or modulo node values</li>
+    <li>call and return from functions, which take the form of subgraphs with named entry points</li>
+    <li>read and write from arbitrary file handles</li>
+    <li>push, pop and pick a section of nodes arranged to act as a stack</li>
+</ul>
+
+<p>The execution of a node may be skipped by having "cond" edges pointing to either zero values or
+non-numeric values. Also, due to the way instruction pointers update and the way several instructions
+are defined, there is a measure of non-determinism that can be introduced depending on what
+edges are available.</p>
+
+<p>The language seemed like an interesting enough idea, but unfortunately nobody had done anything
+with it, and there was only a specification. This has now been fixed. The interpreter currently
+uses a subset of the DOT graph description language for the file format, to enable a text format
+as well as relatively easy conversion to a graph image. If a format that more readily converts to a
+comprehensible graph image is found, a parser for it may be added.</p>
+
+<p>The above example is recorded as follows:
+<code>
+    digraph {
+        1 [label="puts"]
+        2 [label="grasp:main"]
+        3 [label="Hello world!"]
+    
+        1 -> 2 [label="name"]
+        1 -> 3 [label="in"]
+    }
+</code>
+</p>
+
+<p>Source code is available <a href="https://github.com/jedb/esoteric">here</a>.</p>
+
+{% endblock %}
+
-- 
cgit