Download What is Sather

Sather
vs
Java
 Brian Oh
 Ann Win
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Introduction (of Sather)
History
(of Sather)
Comparison between Java and Sather
Sample - “Hello World”
Future
(of Sather)
For more info....
Introduction
 Sather is an object oriented language
 It was designed to be simple, efficient, safe
and non-proprietary.
 Sather aims to meet the needs of modern
research groups and to foster the
development of a large, freely available,
high-quality library of efficient well-written
classes for a wide variety of computational
tasks.
History
 Sather was developed at the International
Computer Science Institute, a research
institute affiliated with the CS department
of UC Berkeley.
 Sather language got its name from the
Sather Tower (popularly known as the
Campanile), the best-known landmark on
UC Berkeley.
History
 Initial Sather compiler (ver 0) was written in
summer of 1990.
 ICSI made Sather (ver 0.1) publicly available on
June of 1991.
 Ver 0.2 and 0.5 followed.
 Sather 1.0 was released in 1994, and most of the
major features such as bound routines and
iteration, etc was first introduced in this version
 Latest version is Sather 1.1, released the summer
of 1996.
History
 Sather was originally designed and implemented
by Steve Omohundro, David Stoutamire and
(later) Robert Griesemer. Boris Vaysman is the
current Sather feature implementor.
 Sather has adopted ideas from Eiffel. But it has
also been influenced by C, C++, Cecil, CLOS,
CLU, Common Lisp, Dylan, ML, Modula-3,
Oberon, Objective C, Pascal, SAIL, School, Self,
and SmallTalk.
Comparison
 Object Oriented Programming
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Like Java, Sather is object oriented.
All entities in Sather are objects, and objects
are defined by classes.
Some basic classes ( INT, FLT, STR). These
represents integers, floating point numbers, and
strings.
Ex) Java
float a=3.0;
int b =5;
String c = “foo”;
Ex) Sather
a:FLT := 3.0;
b:INT := 5;
c:STR := “foo”;
Comparison
 Garbage collection
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Like Java, Sather collects garbage
automatically.
The runtime system does this automatically
when it is safe to do so. But Sather does allow
the programmer to manually deallocate objects,
letting the garbage collector handle the
remainder.
Sather applications generate far less garbage
than typical SmallTalk or Lisp Programs.
Comparison
 Strong Type Language
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Like Java, Sather is a (statically-checked)
strong type language.
Sather is contravariant. That means that it isn’t
possible to get type errors at runtime. It also
means that the Sather programmer needs to
insert explicit type checks (using a typecase) in
places where a covariant compiler would have
inserted an implicit check for you.
Comparison
 No implicit Calls
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Like Java, Sather does explicit method
declarations.
Sather does as little as possible behind the
user’s back at runtime. Meaning, there is no
implicitly constructed temp objects.
Also Sather never converts types implicitly,
such as from integer to character, integer to
floating point, single to double precision, or
subclass to superclass.
Comparison
 Robustness .. Why? Java and Sather both
has characteristics of ....
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no pointer, eliminates of a overwriting of
memory and corrupting data
automatic garbage collection
Strong type language, allows extensive
compile-time checking
explicit method declarations
good exception handling
Comparison
Reasons for using Java over Sather
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Java is very popular...
distributed so that TCP/IP, networking is easier
architecture neutral.. Java can use same code on
many machines while, Sather can not
multithreaded can be done easier.. Java does
multithreading on application level and not at
the operating system level.. So it is a lot easier
to do multithreading with Java then Sather.
Comparison
Reasons for using Sather over Java
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Itegrators .. These methods encapsulate user
defined looping control structures, with creation,
increment and termination check.
Sather is as efficient as C, C++, or Fortran, as
elegant but safer than Eiffel or CLU, and support
higher-order functions as well as Common Lisp,
Scheme, or SmallTalk.. So it is great for wide
variety of research related computational tasks.
It lets you use a large, freely available, high-quality
of efficient well-written classes... Such as Laplace
or Krylov matrix solver..
Hello World Program
Class HELLO
is
main
is
#out + “Hello World!\n”;
end -- end of main
end;
-- end of class HelloWorld
------------------------------------------cs -main HELLO -o hw hw.sa
prompt> hw
Hello World
public class HelloWorld
{
public static void main (String[]
args)
{
System.out.println (“Hello
World”);
} //end of main
}
// end of class HelloWorld
------------------------------------------------javac HelloWorld.java
prompt> java HelloWorld
Hello World
Future of Sather
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Sather will be around but it will not be as
popular as Java, C, C++ or Fortran.
??
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For more info
visit
http://www.icsi.berkeley.edu/Sather
or e-mail
[email protected]
or subscribe the news group
comp.lang.sather