From: Tushar Saxena
Subject: array-leaders in Zetalisp.
Date:
Message-ID: <449@tarski.albany.edu>
What would the following functions mean in Zetalisp :
store-array-leader
array-leader
To abstract out the problem, what does array leader mean in Zetalisp.
Thanks...
Tushar Saxena
······@cs.albany.edu
In comp.lang.lisp you write:
>What would the following functions mean in Zetalisp :
>store-array-leader
>array-leader
>To abstract out the problem, what does array leader mean in Zetalisp.
>Tushar Saxena
>······@cs.albany.edu
In ZetaLisp arrays were optionally provided with an array leader, of
arbitrary length. An array-leader is simply another one dimensional
ART-Q array adjoined to the array (an ART-Q array, in NewSpeak, is
essentially, (ARRAY T)). The array-leader can be referenced only
through the ARRAY-LEADER functions.
Conventionally, (ARRAY-LEADER A 0) is the (FILL-POINTER A).
Similarly, in a named-structure, (ARRAY-LEADER A 1) is the name of the
structure.
Array leaders were often overlaid with a DEFSTRUCT, so that accesses to
the body of the array were done by AREF's, but accesses to slots in the
leader were done using structure accessors. Sometimes, array-leaders
were themselves accessed as arrays, of a different type than the main
array (you might have a small array-leader on a big array of ART-8B,
to associate another heterogenous array with the homogenous array of
bytes).