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From: barmar@think.com (Barry Margolin)
Newsgroups: comp.lang.lisp
Subject: Re: weird common lisp feature
Keywords: read, read-line
Message-ID: <1991Feb21.104336.26012@Think.COM>
Date: 21 Feb 91 10:43:36 GMT
References: <12413@helios.TAMU.EDU>
Sender: news@Think.COM
Organization: Thinking Machines Corporation, Cambridge MA, USA
Lines: 17

In article <12413@helios.TAMU.EDU> e343ca@tamuts.tamu.edu (Colin Allen) writes:
>Can anyone tell me why foo1 below appears to execute the read-line
>before the print, but foo2 executes the print before the read?
>
>(defun foo1 () (print 'hello) (read-line))
>(defun foo2 () (print 'hello) (read))

My guess is that KCL's READ performs a FORCE-OUTPUT call before starting to
read input, but READ-LINE doesn't.  I don't think CLtL specifies anything
about this interaction, so I suggest you put your own call to FORCE-OUTPUT
before any input functions when necessary.

--
Barry Margolin, Thinking Machines Corp.

barmar@think.com
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