CPAN/modules/by-module/MarpaX/JKEGL • Public Open Source Mirror

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=utf-8">
<TITLE></TITLE>
<META NAME="GENERATOR" CONTENT="OpenOffice.org 2.4 (Linux)">
<META NAME="CREATED" CONTENT="20071005;20271700">
<META NAME="CHANGEDBY" CONTENT="Jeffrey Kegler">
<META NAME="CHANGED" CONTENT="20081227;19091200">
<META NAME="CHANGEDBY" CONTENT="Jeffrey Kegler">
<META NAME="CHANGEDBY" CONTENT="Jeffrey Kegler">
<STYLE TYPE="text/css">

</STYLE>
</HEAD>
<BODY LANG="en-US" DIR="LTR">
<H1 CLASS="western">Marpa, a General BNF Parser</H1>
<P>If you've ever written up some BNF and wanted a parser for it,
you've encountered the reality: No standard tool generated a parser
from arbitrary BNF. BNF had to be put into special and highly
restrictive forms like LALR or LL, and this usually required a lot of
tweaking of the grammar. Marpa eliminates these restrictions. It will
generate a parser for <B>any</B> <SPAN STYLE="font-weight: medium">BNF.
That includes even BNF for grammars which are infinitely ambiguous.</SPAN></P>
<H1 CLASS="western">Why call it Marpa?</H1>
<H2 CLASS="western">Warning: Shameless Plug ahead</H2>
<P>Marpa was the greatest of the Tibetan "translators". In
Marpa's time (the 11th century AD) Indian Buddhism was at its
height. A generation of scholars was devoting itself to producing
Tibetan versions of Buddhism's Sanskrit scriptures. Marpa became the
greatest of them, and today is known as Marpa Lotsawa: "Marpa
the Translator".</P>
<P>Translation in the 11th century was not a job for the indoors
type. A translator needed to study in India, with the teachers who
had the texts and could explain them. From Marpa's home in Tibet's
Lhotrak Valley, the best way across the Himalayas to India was over
the Khala Chela Pass. To reach the Khala Chela's three-mile high
summit, Marpa had to cross two hundred lawless miles of Tibet. Once a
pilgrim crested the Himalayas, the road to Nalanda University was all
downhill. Eager to reach their destination, the first travelers from
Tibet had descended the four hundred miles straight to the hot
plains.</P>
<P>The last part of the journey had turned out to be by far the most
deadly. Almost no germs live in the cold, thin air of Tibet. Pilgrims
who didn't stop to acclimatize themselves reached the great Buddhist
center with no immunity to India's diseases. Several large
expeditions reached Nalanda only to have every single member die
within weeks.</P>
<P>There's more about Marpa in my novel, <B>The God Proof</B>, in
which his studies, travels and adventures are a subplot. <I><SPAN STYLE="font-weight: medium">The
God Proof</SPAN></I> centers around Kurt Gödel's proof of God's
existence. Yes, <I>that</I> Kurt Gödel, and yes, he really did work
out a God Proof (it's in his <I>Collected Works</I>, Vol. 3, pp.
403-404). <I><SPAN STYLE="font-weight: medium">The God Proof</SPAN></I>
is available as a free download (<A HREF="http://www.lulu.com/content/933192">http://www.lulu.com/content/933192</A>)
and in print form at Amazon.com:
<A HREF="http://www.amazon.com/God-Proof-Jeffrey-Kegler/dp/1434807355">http://www.amazon.com/God-Proof-Jeffrey-Kegler/dp/1434807355</A>.</P>
</BODY>
</HTML>