Path: utzoo!attcan!sobmips!uunet!samsung!brutus.cs.uiuc.edu!usc!jarthur!bridge2!apple!Apple.COM!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.amiga
Subject: Re: typing right-to-left
Message-ID: <5225@internal.Apple.COM>
Date: 16 Nov 89 20:09:05 GMT
Sender: usenet@Apple.COM
Organization: Objects-R-Us,  Apple Computer, Inc.
Lines: 64
References:<1989Oct22.191705.5211@contact.uucp> <15984@pollux.UUCP> <1249@lakesys.lakesys.com> <12764@polya.Stanford.EDU>

In article <12764@polya.Stanford.EDU> rokicki@polya.Stanford.EDU (Tomas G. 
Rokicki) writes:
> There's one additional consideration---line breaking.  If I type a roman
> alphabet, and then a hebrew alphabet (using caps for the latter), I want
> to type
> 
> a b c d e f g h i j k l
> m n o p q r s t u v w x
> y z A B C D E F G H I J
> K L M N O P Q R S T U V
> W X Y Z
> 
> Now, the Hebrew should be read right-to-left, so what I want to see on
> output (or on the screen) is
> 
> a b c d e f g h i j k l
> m n o p q r s t u v w x
> y z J I H G F E D C B A
> V U T S R Q P O N M L K
> Z Y X W

Just for fun I tried out the Macintosh Hebrew system, and tried this 
example.  When I typed in the characters in the order shown first, I got 
the output:

a b c d e f g h i j k l
m n o p q r s t u v w x
J I H G F E D C B A y z     etc.

Also, the characters were always right justified.  I seem to recall 
reading that in Hebrew you read from right to left, but that if there is 
an English word embeded, then it is written left to right as a separate 
block of text.

When I click between the English and Hebrew I get a split insertion point, 
since the location of the insertion point is physically split on the 
screen.  Typing removes Hebrew letters from the left edge of the line and 
places then at the right of the following line.

Another interesting effect is that you can make a selection that is 
discontiguous on the screen.  In the example above I can select the z and 
A, which results in both letters being highlighted, even though they are 
not adjacent.  

I wouldn't call this a conclusive test, because there's a Control Panel 
option to modify the Hebrew system, and I can't figure out what the 
options do.  

All this happens via a series of routines called the Script Manager.  I 
nthe case of text, there are routines to map a point to a character, 
highlight text, etc.  All these are documented in Inside Macintosh volume 
5.

There's a lot of work besides handling right-to-let characters, in order 
to localize software for th Hebrew or Arabic market.  For example, in 
Hebrew the menu items are right justified.  In Arabic a letter has several 
glyphs depending on its context; if you type a character, it may change 
the appearance of the preceding character.

Larry Rosenstein, Apple Computer, Inc.
Object Specialist

Internet: lsr@Apple.com   UUCP: {nsc, sun}!apple!lsr
AppleLink: Rosenstein1