History of Lisp

1
History of Lisp

• And Functional Programming Languages
• Scotty Smith

2
Overview

• Lambda Calculus
• History of Lisp
• Key Features of Functional Languages
• Haskell
• Why no one uses functional languages

3
Lambda Calculus

• Developed by Alonzo Church in the 1930s
• Type Free
• Deals with recursion, higher-order functions, and
  currying
• ?x.x1 fun x gt x1

4
The Beginnings of LISP

• John McCarthy -1956
• Dartmouth summer research project on Artificial
  Intelligence.
• IBM 704

5
FLPL FORTRAN List Processing Language

• Implemented at IBM by Herbert Gelernter and Carl
  Gerberich
• Written as an extension of FORTRAN

6
Conditional Expressions

• Developed in 1957 1958 at MIT.
• XIF(M,N1,N2).
• Developed a true conditional that evaluated only
  one of its parameters.

7
Innovations Beyond FLPL

• Recursive functions using conditional expressions
• Maplist

8
Implementation of LISP

• Fall of 1958
• MIT
• Started by hand compiling functions written in
  M-expressions
• Prefix notation
• Contains side effects

9
Turing Machines and LISP

• The universal LISP function
• evale,a
• e The LISP expression
• a a list of assignments of values to variables

10
The Interpreter

• Written by S.R. Russell
• Froze the development of the form of the language.

11
Moving On

• Lisp 1.5
• Insertion of elements into lists and deletion
• Lexical scoping
• FUNARG device
• A compiler

12
Other contributions of LISP

• Garbage collection

13
LISP example

• (defun factorial (n)
• (if (lt n 1)
• 1
• ( n (factorial (- n 1)))))

14
Key Features of Functional Languages

• Higher Order functions
• Curried functions
• Lazy Evaluation (Non-strict Evaluation)
• Static typing
• Pattern Matching
• Guards
• fac 0 1
• fac nngt0 nfac(n-1)

15
Haskell

• Purely functional language
• Attempt at a standard functional language
• Features
• Higher order functions
• Lazy evaluation
• Static polymorphic typing
• User-defined datatypes
• Pattern matching
• List comprehensions
• New to Haskell
• I/O system
• Overloading
• Array comprehensions

16
Why no one uses functional languages

• Portability/Availability
• Training
• Popularity

17
References

• Hudak, P. 1989. Conception, evolution, and
  application of functional programming languages.
  ACM Comput. Surv. 21, 3 (Sep. 1989), 359-411.
  DOI http//doi.acm.org/10.1145/72551.72554
• McCarthy, J. 1978. History of Lisp. In
  Preprints of Proceedings of ACM SIGPLAN History
  of Programming Languages Conference. SIGPLAN
  Notices, Vol. 13, pp. 217-223
• Wadler, Phillip. Functional Programming Why no
  one uses functional languages SIGPLAN Notices
  33(8)23-27, August 1998.