Path: utzoo!mnetor!uunet!husc6!bbn!bbn.com!levin
From: levin@bbn.com (Joel B Levin)
Newsgroups: comp.sys.mac
Subject: Re: sprintf() bug?
Message-ID: <20455@bbn.COM>
Date: 3 Feb 88 17:58:03 GMT
References: <MW1oTmy00Xo18P01No@andrew.cmu.edu>
Sender: news@bbn.COM
Reply-To: levin@powell.BBN.COM (Joel B Levin)
Organization: BBN Communications Corporation
Lines: 41

In article <MW1oTmy00Xo18P01No@andrew.cmu.edu> rs4u+@andrew.cmu.edu (Richard Siegel) writes:
:MPW and Aztec, on the other hand, allow you to pass C strings to ROM calls; 
:they *do* have glue. For EVERY SINGLE trap that takes a string, they have 
:glue.
:Icky.

As of MPW 2.0, you can avoid the glue in most cases, because two
things have been added:

1. In the #include files, for each trap where the only differences
between the "glued" version and the trap are string type and calling
sequence, a definition has been added which invokes the trap directly,
e.g., 

    SetWTitle (theWindow, cString);

gets you some glue, but

    SETWTITLE (theWindow, PStringPtr);

gets you the trap without glue.  This doesn't work for OS calls which
don't use the stack; there you always need glue, I imagine even in LSC.

2. The compiler recognizes the "special" character \p at the head of a
string constant and translates it to a length byte, so you can now say

    SETWTITLE (theWindow, "\pNew title");

I have been playing in my spare time with the problem of translating
LSC into MPW (I don't have LSC or a manual, so I'm half blind) --
specifically, TransSkel, TransDisplay, and TransEdit and their demos.
It has been most educational.  Before I learned of these new features
of MPW 2.0, it was a lot of work; this has made it much easier.  When
I have done, I'll probably write up the lessons I've learned so it is
easier for someone else to do this.  (Unless, of course, someone has
written a translator?)

	/JBL

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