Path: utzoo!utgpu!water!watmath!clyde!rutgers!sdcsvax!ucbvax!ARIZONA.EDU!kwalker
From: kwalker@ARIZONA.EDU ("Kenneth Walker")
Newsgroups: comp.lang.icon
Subject: Re:  complicated sorting
Message-ID: <8801032038.AA13538@megaron.arizona.edu>
Date: 3 Jan 88 20:38:47 GMT
References: <397@grand.UUCP>
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: inet
Organization: The ARPA Internet
Lines: 29


	Date: 1 Jan 88 05:33:51 GMT
	From: grand!day@uunet.uu.net  (Dave Yost)
	
	I need to sort a list of records
	according to complicated sort criteria,
	The standard icon sort() routine is
	not making this task easy.  What I
	need is something more like the C
	library qsort routine that lets me
	provide my own comparison routine.
	
	Is there any hope of my finding something
	like this in icon, or am I missing some
	elegant way to do this with the existing
	sort() routine?
	
The comparison routine used by the Icon sort function is built
into the run-time system and cannot be overriden without
modifying Icon.

Sometimes a comlicated sort criterion can be handled by constructing
artifical keys for records such that a key sorts the corrosponding
record where it needs to go in the sequence. The records can then
be put in a table using the keys and the table can be sorted to
produce the desired sequence of records. The artifical keys would
typically be strings. If such keys are not easy to produce, your
best bet is probably to write a sort procedure in Icon specific to
your application.