CS342b – winter 2006
                      PROGRAMMINGLANGUAGES
                                      Lucian Ilie
          c
         
2006by Lucian Ilie
                                               c
               CS342b – Programming Languages – winter 2006 – 
 2006 by Lucian Ilie                                          2
               1      Introduction
               - why study (concepts of) programming languages
               - classification of languages
               - programming domains
               - evaluation criteria
               - levels of programming languages
               - compilation and interpretation
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               CS342b – Programming Languages – winter 2006 – 
 2006 by Lucian Ilie                                          3
               1.1       General questions
               1.1.1       Whyare there so many programming languages?
               - evolution – we’ve learned better ways of doing things over time
               - socio-economic factors – proprietary interests, commercial advantage
               - orientation toward special purposes
               - orientation toward special hardware
               - diverse ideas about what is pleasant to use
               1.1.2       What makes a language successful?
               - easy to learn (BASIC, Pascal, LOGO, Scheme)
               - easy to express things – easy to use once fluent – ”powerful” (C++, Common
               Lisp, APL, Algol-68, Perl)
               - easy to implement (BASIC, Forth)
               - possible to compile to very good (fast/small) code (Fortran)
               - backing of a powerful sponsor (COBOL, PL/1, Ada, Visual Basic)
               - wide dissemination at minimal cost (Pascal, Turing, Java)
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               CS342b – Programming Languages – winter 2006 – 
 2006 by Lucian Ilie                                          4
               1.1.3       Whydowehaveprogramming languages?
                           – what is a language for?
               - way of thinking
                  – way of expressing algorithms
                  – from the user’s point of view
               - abstraction of virtual machine
                  – way of specifying what you want the hardware to do without getting down
               into the bits
                  – from the implementor’s point of view
               Knuth: “Computer Programming is the art of explaining to another human
               being what you want the computer to do.”