Lecture #1 Programming Languages MISHRA

G22.2210

Programming Languages: PL I

B. Mishra
New York University.


Lecture # 1
Room 801, Warren Weaver Hall
251 Mercer Street
Tel.# 212.998.3464 (Voice Mail)
E-mail:mishra@cs.nyu.edu
WWW: See http://cs.nyu.edu/

---Slide 1---
Text Books

• RAVI SETHI, Programming Languages---Concepts and Constructs, (2nd Edition), Addison Wesley. ISBN 0-201-59065-4.

• Other Recommended Books

  • RYAN STANSIFER, The study of Programming Languages, Prentice hall, Inc, Engelwood Cliff. ISBN 0-13-726936-6.

  • BJARNE STROUSTROUP, C++: Programming Language, Addison Wesley Publishers.ISBN 0-201-12078-X.

  • JAMES GOSLING, Java Language Specification, Addison Wesley. ISBN 0-201-63451-1.

  • J. BARNES, Programming in ADA 95 Addison Wesley. ISBN 0-201-87700-7.

  • GUY STEELE, Common Lisp Manual, Digital Press. ISBN 0-932376-41-X.

  • STEPHEN WOLFRAM MATHEMATICA: A System for Doing Mathematics, Addison Wesley. ISBN 0-201-51507-5.

---Slide 2---
Administrivia

• Office Hours
  12:00 noon--1:00pm, Thursday
  Room 801: Warren Weaver Hall
  (Also, by appointment)

• Tests and Assignments
  1. Home Works (Some programming)
     About 4 Assignments
     of the total Grade
  2. Mid-Term (1 Hr Quiz, Closed Book)
     of the total Grade
  3. Final (2 Hrs, Closed Book)
     of the total Grade

---Slide 3---
Who is interested in
Programming Languages?

• Users--- Issues:
  • Ease of Programming
  • Productivity
    

    i) Prototyping, ii) Optimization, iii) Correctness, iv) Flexibility v) Reusability

  • Readability
    

    i) Self-documenting, ii) Syntax, iii) Semantics

  • Interface
    

    i) Libraries, ii) Other languages

---Slide 4---
Language Designers

• Issues:
  • Lexical Structure
  • Syntactic Structure
  • Semantic Structure
    

    i) Every feature has a well-defined meaning.

    ii) Interaction among the features

  • Operations
    

    i) Bit Operations, ii) Typed First-Class Objects:
    int, Boolean, float, double, ,
    iii) Objects, iv) S-expressions, v) Logical expressions vi) Rules and Patterns, vii) Sets

    
    ---Low level vs. High level---
  • Interactive/Dynamic vs. Static

  • Imperative vs. Declarative

---Slide 5---
Compiler Writers

• Issues:

  • Separation between

    
    Language & Machine-dependent Features

    ---Portability---

  • Compile Time vs. Run Time
  • System Interface
    

    i) Operating System, ii) File System, iii) Separate Compilation, iv) Programming Environment (Version Management, Editor, Debugger, Profiler)

  • User Interface
    

    i) Error reporting/Recovery, ii) Assertions & Checks, iii) Options Control, iv) Preprocessing

  • Performance
    

    i) Compiler (Size/Speed), ii) Generated Code (Size/Speed)

  • Compiler-Compiler

---Slide 6---
Why are we Interested in Programming Languages?

• Mostly as a USER
  Recognize and understand common features

  1. Makes it easy to learn
  2. Understand common idioms/phrases
     (Stylized and Readable Code)
  3. Improve Productivity

---Slide 7---
A Brief History of Programming Languages

Early Languages

• Algebraic Interpreter: MIT for the Whirlwind computer (1950).
• A-2: Grace Murray Hopper. For UNIVAC. (1950)
• FORTRAN: FORmula TRANslator. John Backus & his team at IBM. (1953)

  Simple compiler capable of producing efficient code. First Fortran compiler construction: 1955--1957.

  Standardized by ANSI (American National Standards Institute) in 1966 and by ISO (International Standards Organization) in 1978. Latest standard---ANSI X3.198--1992, September 1992.

---Slide 8---
History (Contd)

• ALGOL: ALGOrithmic Language. Committee consisting of GAMM (Gesellschaft für angewandte Matheamtik und Mecahnik) and ACM. 1958--1960. ALGOL 60.

  Block structure
  Recursive Procedures
  Data Types
  Scope Rules (Lexical)

  ALGOL 68---Parallel computing, Semaphores, Coercion, Overloading, Flexible Arrays

  Hard to implement.

---Slide 9---
History (Contd)

• LISP: LISt Processing Language. John McCarthy & his colleagues in MIT. Late 1950s

  A list of symbols: E.g., word in a sentence, attributes, algebraic expressions
  List represents both data and expressions (Cambridge Polish Notation.)---S-expressions
  Functional Programming

  Dialects: MacLisp, FranzLisp, BBNLisp...
  Standardization: Common LISP and Scheme. 1975--1985.

• SIMULA: Royal Norwegian Council. Kristen Nygaard & Ole-Johan Dahl, Early 60s.

  Simulation of Physical entities
  Objects with independent existence--OOPS. SIMULA 67 Beta: successor of Simula in the 90's

---Slide 10---
History (Contd)

• COBOL: CODASYL (Committee on Data Systems Language) executive committee, sponsored by US DoD. May 1959

  Mainly for business Data processing applications (e.g., payroll)

• APL: A Programming Language. Ken Iverson. Early 60s.

  Succinct representation obtained by compositional application of operations on high-level structures such as arrays and matrices.

• SNOBOL: David Farber, Ralph Griswold & Ivan Polonsky at Bell Labs. Mid 60s.

  Processing of string data
  Concepts of generators. Pattern matching by unification
  Icon: successor of SNOBOL in the mid 80's

---Slide 11---
History (Contd)

Recent Languages

• PL/I: Advanced Language Development Committee sponsored by IBM. Mid 60s.

  Goal was to replace FORTRAN and COBOL by a more powerful language.
  ANSI standard in 1976. ``General Purpose Subset'' in 1981.
  As a language it failed, mostly due to its complexity.

• BASIC: Beginner's All-Purpose Symbolic Instruction Code. John Kemeny and Thomas Kurtz of Dartmouth College. Early 70s.

  Easy to learn, code and debug.
  ANSI Standard in 1978. True BASIC in 1985.

---Slide 12---
History (Contd)

• C: Dennis Ritchie at Bell Labs. 1972. Influenced by B and BCPL (Ken Thompson).

  Low level language. With greater access to hardware environment (necessary in applications such as graphics, networking, etc.)
  Good interface with operating system (UNIX and the libraries)
  ANSI standard in 1989.

• BLISS: Bill Wulf and Nico Habermann of Carnegie-Mellon. Mid 70s.

  Low level abilities.
  Optimizing compiler for BLISS 11 to run on PDP 11.

---Slide 13---
History (Contd)

Structured Languages

• Pascal: Niklaus Wirth, 1971.

  Influenced by ALGOL 68 (ALGOL W).
  Simple, 1 Pass compiler. First compiler written in FORTRAN by a single graduate student.
  Pedagogic language. Used for teaching structured program development via stepwise refinement.
  User-defined types.
  Standard Pascal lacks dynamic arrays. Makes its hard to use for many real applications.

• Modula: Niklaus Wirth. Early 80s.

  Allows programs to be organized in modules
  Some amount of encapsulation

---Slide 14---
History (Contd)

Object Oriented Languages

• Smalltalk: Alan Kay, Xerox Parc (KiddiKomp project). Summer of 71.

  Object Oriented Programming (OOP).
  Concept of classes. Object is an instance of a class.
  Classes are organized in a class hierarchy. Properties can be inherited from super/base classes.

• C++: Bajrne Stroustroup. 1982--1985.

  Influenced by SIMULA. Evolved from an earlier version called ``C with classes.''
  Class mechanisms, Inheritance, Friend-mechanisms. Template (polymorphisms).
  Powerful, yet efficient.

• Ada: Jean Ichbiah of Honeywell of France, 1983.

---Slide 15---
Imperative Languages

---Slide 16---
Turing Awards

Or, Why you may want to design a Programming Language.

---Slide 17---
The
INTERCAL
Programming Language

• Donald R. Woods & James M. Lyons

• The full name of the compiler is ``Compiler Language With No Pronounceable Acronym,'' which is, for obvious reasons, abbreviated to ``INTERCAL.''