Prograph 2.0
Volume Number: 7
Issue Number: 1
Column Tag: Tools of the Trade
By Dave Kelly, MacTutor Editorial Board
Prograph Grows Up
As announced earlier in 1990, TGS Systems’ compiler for the Prograph
object-oriented programming environment is here. Refer to the March 1990 (Vol. 6
No. 3) MacTutor for an introduction to the Prograph environment. Prograph is now a
real development environment. If you have been waiting for the Prograph compiler to
try Prograph, the waiting is over. Prograph is a delightful language to use. I have
enjoyed working with it. Now that the compiler is available, Prograph has been added
to the list of viable development languages available on the Macintosh.
There are a few improvements from Prograph Editor/Interpreter version 1.2 to
2.0. Some of the improvements include:
• Undo of Delete
• Propagate Comments
• cmd key equivalents improved (cmd-I for Info etc.)
• Ability to Hide/Show classes
• Memory Status item in Info menu
• Check Program status in Info menu for checking syntax.
• Improved Options panel: Option to not close editor windows when executing a
method; option to make backups automatically.
• Paste pictures and icons directly from the clipboard into Pict (System Class)
and Icon window items in Application builder.
• use shift-option-command-click to open a value window
• Menu item editor permits menu items to have either style information or
multi-key key equivalents.
• wind-draw-prep method provided in class Window to do SetPort on the window.
• Window-items with click methods now provide the event record as an input to
the click method.
• several new primitive (methods provided by Prograph) and full support of
Inside Macintosh volumes I-V is provided (with a few exceptions).
• XPrim C-code protocol has been changes to that the same code may be used in
both the interpreter and the compiler, with only a compiler switch.
• New XPrim called XLink™ from CEL Software that lets you call HyperCard
XCMDs and XFCNs.
THE COMPILER
The obvious advantages to compiling a program is that compiled programs run
faster than interpreted programs, large interpreted programs take up more space than
compiled programs, and interpreted programs require that the interpreter be present
(they are not stand alone). In addition, most developers don’t want their programs
modified; interpreted programs are open to modifications.
You can almost use the Prograph Compiler blindfolded. The compiler can be
launched directly from the interpreter and in Multi finder, you can switch between the
two applications. To compile a program, you must create a Prograph project. Clicking
in the blank area of the project window prompts you for your program file and adds two
special library files automatically. One file, SCLibrary, contains code for the
Prograph system classes, and must be present if your Prograph program uses the
system classes. The file Library contains runtime and Mac Toolbox code; this file must
always be included. Next, just select Build Application from the Project menu and a
dialog prompts you to give a name for you new application. Or you may choose Run and
run the program immediately after compiling. It’s as simple as that.
There are a few compiler options available too. Options include use of
68020/30 instructions, Integer Only Arithmetic, Multifinder settings, creator
signature and other options. You may also add THINK C or MPW C object files. This
code cannot be run under the interpreter. Calls to these routines must have empty
methods, or stubs, when you run your Prograph program in the interpreter
environment.
PERFORMANCE
You’re probably wondering just how the Prograph compiler compares to other
compilers. The smallest application that can be created with Prograph is about 50K.
The Prograph Library adds 50K to any application. Then if you use system classes
(which most people will), you add another 80K, a total of 130K overhead). After the
overhead, the code size varies depending on what is in the code.
Before doing any benchmark comparisons with regard to this, I must caution you
to realize that there are many other factors which effect the overall performance that
benchmarks cannot adequately show. With that in mind, here are some results of
benchmarks I ran with Prograph. I only checked the compiler response since I’m not
interested in comparing interpreters. The Prograph interpreter is great for
development, debugging, and testing your program. However, any interpreter is SLOW!
no matter how you look at it e specially when compared to a compiled system.
Remember the accuracy benchmark I used to compare BASIC a few years ago.
This program re-written for Prograph is shown in the first program. (The printout
was generated from Prograph printed output). The accuracy method shown at the bottom
first gets the tick count and then calls the main loop with the initial conditions set. In
the main loop, s is added to x times x and x is added to .00123. This loop is repeated
1000 times and then the answer is displayed. On a Macintosh Plus, the benchmark gave
the correct answer of s=503.5438021499999912 and
x=1.229999999999999985 in 9.25 seconds. The same routine took .85 seconds on a
IIci (with cache card). As you can see there was some round off errors past the 8th
significant digit, but the result was acceptable. The time should be ignored since I also
used the System class (i.e. the Macintosh shell) running when I ran the benchmark. I
suspect that this slows down performance because of event handling. Also, the Evaluate
operation (for evaluating mathematical expressions) is more efficient for math
operations. I’m not using the Evaluate operation; the effect of different operations will
effect the results.
The next benchmark is the familiar Sieve of Erastothenes. The version shown
below is the fastest of the versions of the Sieve that I ran and I am still cautious when
looking at these results. Depending on the implementation of the loops and allocation of
memory for variables, etc. the speed can vary quite a bit. The routine shown executes
the prime number generation only one time. In the comparisons I have done in the
past, I ran 10 iterations. In this case I multiplied the result by 10 to approximate
what the result would be for 10 iterations. The Macintosh Plus generated 1899 primes
(10 iterations) in 126 seconds. This turns out to be about the same time as True Basic
(Ref. The Complete MacTutor, Vol. 2, pg. 380-381). On the IIci, the time was about
14 seconds.
As I stated to begin with, the results don’t necessarily represent the overall
performance. According to these results, it is evident that there is some performance
lost in exchange for the ability to use object oriented programming. This implies that
if speed is a requirement Prograph may not be the best choice to use.
Mark Szpakowski of Prograph sums it all up: “We did comparison benchmarks
between Prograph 2.0 and Parc Place Systems’ Smalltalk-80 on a Mac CX, both
running compiled, and found performance about the same (some things we were better,
some things they were better). Comparing integer and float computations with ThinkC,
ThinkC is much faster. However, comparing OOP operations, such as method selection
based on class of input data, we have a slight edge over ThinkC 4.0. The bottom line is
that if someone wants or needs high performance in math computations, they can write
their code in Think or MPW C or assembler, and then link that with their compiled
Prograph code. For most stuff, though, Prograph is not only productive, but, fun!”
Learning and using Prograph is fun and the learning curve is much shorter than
for other languages. In spite of the benchmark results, I still like Prograph enough to
continue using it to develop real applications. In addition, C object code can be used to
speed up the slower routines.
Prograph 2.0 is available from:
TGS Systems
1127 Barrington St.,Suite 19
Halifax, NS B3H 2P8
Canada
(902) 429-5642
FAX: (902) 425-0561
Order toll free from the US: 1-800-565-1978
AppleLink: CDA0242
CompuServe: 73300,3460
BIX: szpak
Bitnet: gunakar@tuns
America Online: szpak
The W.E.L.L.: szpak
Price: $395 + $5 shipping
Requires: Mac Plus with 128K ROM; 1M RAM
No copy protection
In addition a Prograph BBS operated by TGS Systems is at (902) 423-4921,
accessible at 300/1200/2400 baud, 8 bits, no parity, almost 24 hrs/day. This has
private mail, public message areas, and file areas for uploading and downloading
Prograph code.