Language Choices

1
Language Choices

• CS2340
• Spring 2004

2
Object-Oriented Development

• Requirements What does customer want?
• OOA
• Design How are we going to meet requirements?
• OOD
• Implementation Building the thing
• OOP

3
The Challenge
Picking the right language for the right job!
Smalltalk
?
C
Eiffel
C
Forth
Tcl/Tk
Basic
COBOL
Ruby
SQL/4GL
Ada
C
Fortran
Java
IDL
Assembler
Python
4
History of Programming Languages

• Program one instruction at a time in binary or
  hex
  
• Examples
• 101110101010011
• AB3E6
• Software cost 24 x the hardware
• Program using assemblers
• jumps, load, store, etc

5
History

• Program using a domain specific high-level
  language
  
• FORTRAN for Science
• Developed by IBM 1957
• Algol for Science and Publishing
• Developed by international committee 1958
• COBOL for Business
• Developed by committee 1959
• LISP for Artificial Intelligence
• Developed by John McCarthy 1959

6
History

• Program using general purpose high-level
  language
  
• PL/1 (Designed to include everything!)
• Developed by IBM in 1965
• Pascal (Designed to be simple)
• Developed by Niklaus Wirth in early 1970s
• Domain specific used as general purpose
• C (Designed for system implementation)
• Developed at Bell Labs in the 1970s

7
History

• Program using objects
• Smalltalk
• Designed by Alan Kay
• Developed by Xerox and released 1980
• C
• Developed by Bjarne Sroustrup at Bell Labs and
  released 1985
  
• Java
• Developed by Sun
• Released 1995
• .NET (C, Visual Basic, etc)

8
Current Popular Languages

• Visual Basic
• Java
• C
• C
• C
• Fortran
• Lisp
• COBOL
• Javascript
• Python
• Perl

9
Scripting

• Python
• Good for text processing and web
• Javascript
• Developed by Netscape
• Perl
• Language of choice for web site scripting
• Visual Script
• Developed by Microsoft
• Ruby
• OO scripting language

10
History Summary

• Computer languages have moved away from the
  hardware
  
• Computer languages have gotten more complex to
  handle more complex problems
  
• Computer languages have gotten more inefficient
  but easier to use
  
• Software vs Hardware costs increasing

11
Pros and Cons of Languages
12
How to Pick a Language?

• What do you want to do?
• Some languages are special purpose
• How fast does the program need to be?
• How fast does development need to be?
• How easy is it to do what you want to do in the
  language?
  
• How hard will it be to maintain and extend?
• How safe does the program need to be?
• What does it cost?

13
Definitions

• Expressibility Ability to express an idea
• Expressiveness Ease of expressing that idea
• For example
• String processing in Fortran
• Numeric Analysis in COBOL

14
Some Applications

• Digital Signal Processing
• Assembler
• C
• Hard Real-Time Embedded System
• C/C
• Web-Enabled E-Commerce
• Java
• Prototype Development
• Visual Basic
• Smalltalk

15
More Applications

• Operating System
• Assembly
• C
• Flight Control System
• Ada
• Nuclear Reactor Control System
• Ada
• MIS System
• SQL/ 4GL
• Text Processing
• Perl

16
The wrong answer

• Everyone is using XXXXX.
• Where XXXXX is the current favorite.
• However recognize that
• If everyone else is really using XXXXX there may
  be better
  
• Libraries
• Applications
• Development Environments

17
How can I make a pseudo-scientific choice??

• One Technique Decision Matrix
• List languages and criteria
• Assign weights
• Rank each language
• Sum weights
• Select highest score

18
Talking Head Prediction

• Type-safe vs. Dynamically-Typed
• Ease of revision/Testing vs. Strict parameter
  enforcement
  
• Cost of Deployment/Modification
• Ruby, Python, Smalltalk will grow C, Ada and
  Java will fade.
  
• Robert Martin