1. A BRIEF HISTORY OF PROGRAMMING LANGUAGES

2. high-level programming languages
Figure 2.1
Genealogy
of common
high-level programming languages

3. TIOBE

4. Pseudocodes (1949) - Short code; 1949; BINAC; Mauchly
- Expressions were coded, left to right
- Speedcoding; 1954; IBM 701, Backus
- Pseudo ops for arithmetic and math functions
- Conditional and unconditional branching
- Autoincrement registers for array access
- Slow!
- Only 700 words left for user program

5. Dramatically changed forever the way computers are used
FORTRAN (mid-late 1950’s)
Emphasis on scientific programming
FORTRAN (not implemented)
FORTRAN I 1957
FORTRAN II 1958
FORTRAN IV
FORTRAN
FORTRAN
FORTRAN
Dramatically changed forever
the way computers are used

6. FORTRAN in depth FORTRAN II – 1958 Independent compilation
FORTRAN IV –
Improved data typing
ANSI standard in 1966
FORTRAN 77 – 1978
Better logical statements
FORTRAN 90 – 1990
Allows recursion
Syntactic changes
FORTRAN 95 – 1995
Deletes some deprecated features
Deprecates more features

7. LISP (1959) Designed at MIT by McCarthy
Still the dominant language for AI
Pioneered functional programming
Syntax is based on lambda calculus
Contemporary dialects:
COMMON LISP, Scheme
Object-oriented versions:
Flavors, LOOPS, CLOS
Related languages:
ML, Miranda, Haskell

8. Scheme Developed at MIT in mid 1970s Small
Extensive use of static scoping
Functions as first-class entities
Simple syntax (and small size) make it ideal for educational applications

9. COMMON LISP
An effort to combine features of several dialects of LISP into a single language
Large, complex

10. ALGOL Goals of the language Close to mathematical notation
Good for describing algorithms
Must be translatable to machine code
Not meant to be implemented, but variations of it were
MAD, JOVIAL
IBM initially enthusiastic, but all support dropped by mid-1959

11. ALGOL 58 (1958) Formalized the concept of the data type
Compound statements (begin ... end)
Parameters were separated by mode (in & out)
Names could have any length
Arrays could have any number of subscripts
Subscripts were placed in brackets
Semicolon as a statement separator
Assignment operator was :=
if had an else-if clause
no i/o - “would make it machine dependent”

12. ALGOL 60 (1960) New Features: Block structure; multiple scopes
Better parameter passing
Recursion
Stack-dynamic arrays
Successes:
Standard for publishing algorithms for over 20 years
All subsequent imperative languages are based on it
First machine-independent language
First formally defined syntax
Failures:
Programs non-portable
Hard to implement
Intrenchment of FORTRAN
Formal syntax description
Lack of support of IBM

13. COBOL (1960) Based on FLOW-MATIC, which had:
Names up to 12 characters, with embedded hyphens
English names for arithmetic operators
Data and code kept completely separate
Verbs as the first word in every statement
COBOL Design Problems:
Arithmetic expressions?
Subscripts?
Fights among manufacturers
Contributions:
Macros
Hierarchical data structures
Nested selection statements
Long names with hyphens
Separate data division

14. BASIC (1964) Intended for teaching how to program
Interactive interpreted environment
Designed by Kemeny & Kurtz at Dartmouth
First widely used language with time sharing
Current popular dialect: Visual BASIC

15. PL/I (1965) Contributions: First unit-level concurrency
First exception handling
Switch-selectable recursion
First pointer data type
First array cross sections
Comments:
Many new features were poorly designed
Too large and too complex
Was (and still is) actually used for both scientific and business applications

16. APL (1962) Array and matrix processing
Dynamic typing and dynamic storage allocation
Designed as a hardware description language
Highly expressive
Programs are very difficult to read

17. SIMULA 67 (1967) Introduced classes data and operations together
Designed primarily for system simulation
Based on ALGOL 60 and SIMULA I
Primary Contribution:
Classes, objects, and inheritance

18. ALGOL 68 (1968) Primary design goal: orthogonality
Based on ALGOL 60, but not a superset

19. Pascal (1971) Designed for teaching structured programming
Small, simple, nothing really new
Many subsequent languages based on Pascal
Delphi
Occam

20. C (1972) Designed for systems programming Powerful set of operators
Poor type checking
Initially spread through UNIX
Flexible, but unsafe

21. Prolog (1972) Logic language, non-procedural
Programs are sets of facts and rules
Not proven to be widely applicable

22. Ada (1983 - began in mid-1970s) Contributions:
Packages; Exception handling; Generic program units; Concurrency
Comments:
Competitive design
Included all that was then known about software engineering and language design
First compilers were very difficult: Five years to develop the first really usable compiler
Ada 95 (began in 1988)
Support for OOP through type derivation
New concurrency features
More flexible libraries

23. Smalltalk (1972-1980) Object-oriented programming language
Really a graphical environment
Developed at Xerox PARC
First full implementation of an object-oriented language
Pioneered the GUI everyone now uses

24. C++ (1985) Design goal: no performance penalty, relative to C
Features:
Parameterized types (templates)
Exception handling
Operator overloading
Facilities for object-oriented programming added to C
Large and complex
Rapidly grew in popularity, along with OOP
ANSI standard approved in November, 1997!!

25. Java (early 1990’s) Developed at Sun Microsystems
Smaller, simpler, more reliable C++
Significantly simplified
All code must be encapsulated in classes
Concurrency support (threads)
Garbage collected
JavaScript (1995)
Began as LiveScript at Netscape
Client-side HTML-resident scripting language
Used for designing client-side dynamic documents
Purely interpreted

26. Scripting Languages
Earliest scripts were files which stored a sequence of OS commands
interpreted by simple OS facility
UNIX had a profound influence sh
ksh
awk
Not all are Turing Complete

27. Perl (1987) Related to ALGOL only through C A scripting language
A script (file) contains instructions to be executed
Other examples: sh, awk, tcl/tk
Developed by Larry Wall
Perl variables are statically typed and implicitly declared
Three distinctive namespaces, denoted by the first character of a variable’s name
Powerful but somewhat dangerous
Widely used as a general purpose language

28. Scripting Languages for the Web
JavaScript
Used in Web programming (client side) to create dynamic HTML documents
PHP (1994)
Server-side HTML-resident scripting language
Purely interpreted
Python
An OO interpreted scripting language

29. C# (2000) Microsoft The primary language of the .NET platform
A successor to both Java and C++
Includes most of the features of Java, with some modifications, as well as some of the features of C++ that were left out of Java
Can be used for both .NET applications for the Web, as well as a general-purpose programming language

30. Markup/Programming Hybrid Languages
XML : eXtensible Markup Language
a metamarkup language
eXtensible Stylesheet Language Transformation (XSTL) transforms XML documents for display
JSP : Java Server Pages
a collection of technologies to support dynamic Web documents

31. Summary
Development, development environment, and evaluation of a number of important programming languages
Perspective into current issues in language design