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Prograph 2.0

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 Multifinder, 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 especially 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.