5096e146535a857645d0d70831d9e70c.ppt
- Количество слайдов: 29
Confessions of an Academic Ada Zealot Martin C. Carlisle Associate Professor United States Air Force Academy Department of Computer Science 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Disclaimer • Opinions contained herein are those of the author, and not necessarily those of the US Air Force Academy, US Air Force, or United States Government. 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
History (1980 s) $7600. 00 3 October 2001 $435. 00 Confessions of an Academic Ada Zealot Martin Carlisle $640. 00
Another 80 s Do. D acquisition • ANSI/MIL-STD-1815 A-1983 (the Ada programming language) • Started in 1974. Requirements in 1978, standardized in 1983. 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
The Mandate • Required for all Do. D critical systems (1983) • Required for use in Do. D weapons systems (Deputy Sec. Of Defense, March 1987) • Required for all Do. D software (June 1, 1991) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Ada in 80 s • Compilers were expensive and slow • As an innovative language, hard to implement 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Major Contracts • 1992: Air Force gives contract to NYU for GNAT. Ada Core Technologies established in 1994. • 1995: Academic Ada contract to Intermetrics 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
The Mandate’s Effect • In 1994, 33% of code written in Ada, 22% in C, 37% in “other approved languages” • “Many projects have ignored or manipulated the policy on waivers, employing languages other than Ada without the required waiver ” (NRC) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
The Mandate Destroyed • Based on the NRC report, Ada no longer mandated (March 1997) • But where’s the $15 million/year? • AJPO closed Sept 1998 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Why we STILL teach Ada at USAFA • Clear syntax • Supports software engineering principles • Cheaper development costs – Time constraints for cadets are large! 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Steelman Requirements • Ada 93% • Java 72% • C++ 68% • C 53% "Ada, C, C++, and Java vs. The Steelman" David Wheeler, Institute for Defense Analysis, 1997 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Comparing Costs (C) • Development costs of Ada were roughly half those of C, with C code having an order of magnitude greater errors. 75% of the programmers were experienced in C, while only 25% were experienced in Ada. Stephen Ziegler, Rational Corp. "Comparing Development Costs of C and Ada" 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Comparing Costs (C++) • Ada error rate was approximately 50% of the norm. Cost of delivery of Ada was lower. Reifer Consultants "Quantifying the Debate: Ada vs. C++" 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Comparing Costs (C++) • Analysis of info systems and C 3 systems showed Ada had a 35% advantage in frontend development costs and a 70% advanatage in maintenance costs. "Ada and C++: A Business Case Analysis" USAF Report. (TRW) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Comparing Languages (FAA) • Evaluation included capability, efficiency, availability/reliability, maintainability/ extensibility, lifecycle cost, and risk. Ada 78. 8 C++ 63. 9 C 59. 5 FORTRAN 47. 0 Software Engineering Institute (for FAA) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Comparing Ada and Java • Concludes Java is more difficult to teach to intro programmers because of complex syntax for simple programs, lack of pointers, difficulties with types. http: //www. act-europe. fr/texts/papers/ada-java -teaching-comp. pdf (Brosgol) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Eliminating Bugs • "My Hairiest Bug War Stories" CACM April 1997. Ada compilers unaided would have caught 88% of these bugs. John Mc. Cormick ("Ada Kills Hairy Bugs") 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Languages in CS 1 • Ada instructors believed their current language was best at a ratio of 3 -4 x over C and C++ instructors. http: //academic. scranton. edu/faculty/beidler/ levy/ 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Nobody uses Ada • Ada is used in lots of surprising places, including the NYC Subway and the Hertz navigation system. http: //www. seas. gwu. edu/~mfeldman/adaproject-summary. html 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Ada in Universities • Approximately 150 universities use Ada in 1 st or 2 nd computer science course • Number relatively constant over last couple of years • http: //www. seas. gwu. edu/~mfeldman/adafoundation. html 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
AP Board • Starts in Pascal (first offered 1984) • Moves to C++ in 1998 -1999 (despite open opposition from ACM educators) • Moves to Java in 2003 -2004 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
What kinds of tools are we looking for? • Cheap • Simple • Powerful • Must compare favorably with Visual Studio, freely available Java tools 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Tools to Support Ada in Education and Elsewhere • GNAT/Ada. GIDE 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • JGNAT Connect Four applet demo 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • Gtk/GLADE/GVD – Primarily Linux based, but Windows version – XML based GUI builder – Multi-language debugging platform 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • RAPID – Multi-platform GUI builder http: //www. usafa. af. mil/dfcs/bios/carlisle. html 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • CLAW – Windows GUI builder – Free demo, pay for full version RR software (www. rrsoftware. com) 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • GWindows – Free OO Windows library – Currently no GUI builder www. adapower. com 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle
Leveraging Technology with Ada • GNATCOM – MS reusable object technology http: //www. adapower. com 3 October 2001 Confessions of an Academic Ada Zealot Martin Carlisle