CS 150 lecture 2

Review

• Reasons for studying programming languages• Language evaluation criteria

– Readability• Simplicity?• Orthogonality?

– Writability

• Influences on language design• Language design trade offs• Implementation methods

“those that forget their history are doomed to repeat it.”

Thanks to Google images…

Plankakul

• Konrad Zuse• Why did this come to

be?

Speedcoding

• John Backus

Univac Compiling System

• Grace Murray Hooper

Von Neumann Machines

•

Fortran

• John Backus and group

LISP1958

(defun append (L M) (cond ((null L) M) (T (cons (car l) (append (cdr L) M)) )))

John McCarthy

ML (Meta Language) 1980’s

• Robin Milnerfun size Empty = 0 (* size

of b_tree = # nodes *) | size (Node (lft, _, rht)) = 1 + size lft + size rht;

Peter Naur : ACM and GAMMALGOL

ALGOL 58 Program// the main program, calculate the mean of // some numbers begin integer N; Read Int(N); begin real array Data[1:N]; real sum, avg; integer i; sum:=0; for i:=1 step 1 until N do begin real val; Read Real(val); Data[i]:=if val<0 then -val else val end; for i:=1 step 1 until N do sum:=sum Data[i];

avg:=sum/N; Print Real(avg) end end

Grace Murray Hopper, againCOBOL 1959

PROCEDURE DIVISION. MAIN-PARAGRAPH. MOVE X TO YIF Y > Z THEN ADD Z TO X

MOVE X TO Z ELSE DISPLAY END-IF

STOP RUN.

John Kemeny of DartmouthBASIC Dartmouth 1960’s

LET X=5

DIM INTLIST(99)

INPUT LISTLEN

PL/I

• Because of?

Ken Iverson --APL 1960

•

Ralph GriswoldSNOBOL 1960’s

• String pattern matching

SIMULA 1967

• Basic idea of class• Nygaard and Dahl

Niklaus WirthPascal

• Simplicity by design• Then Modula• Then Oberon

Ada 1970’s to 1983

• What is ADA for?

Alan Kay : Smalltalk

• OOP• Xerox Parc

C

• Dennis Ritchie• Based on the

language B• At Bell labs – used in

the UNIX project

C++

• Bjarne Stroustrup

Bertran Meyer : Eiffel• hybrid

Jame Gosling : Java

• SUN

C#

• Anders Hejlsberg• Designer of Turbo

Pascal• Microsoft product

For all you Linux buffs

Class discussion

• Continuation of evolution? What would be the ideal programming language today?

Assignment

• How/In what terms did the speaker discuss evolution in the video?

• Is he an advocate of functional programming languages or no?