Speaking at a software conference in 2009, Tony Hoare hyperbolically apologized for "inventing" the null reference:[27][28]
I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (ALGOL W). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.[29]
For many years under his leadership, Hoare's Oxford department worked on formal specification languages such as CSP and Z. These did not achieve the expected take-up by industry, and in 1995 Hoare was led to reflect upon the original assumptions:[30]
Ten years ago, researchers into formal methods (and I was the most mistaken among them) predicted that the programming world would embrace with gratitude every assistance promised by formalisation to solve the problems of reliability that arise when programs get large and more safety-critical. Programs have now got very large and very critical – well beyond the scale which can be comfortably tackled by formal methods. There have been many problems and failures, but these have nearly always been attributable to inadequate analysis of requirements or inadequate management control. It has turned out that the world just does not suffer significantly from the kind of problem that our research was originally intended to solve.
Awards and honoursedit
ACM Programming Systems and Languages Paper Award (1973)[31] for the paper "Proof of correctness of data representations"[32]
Member of the National Academy of Engineering (2006) for fundamental contributions to computer science in the areas of algorithms, operating systems, and programming languages.
C. A. R. Hoare (1985). Communicating Sequential Processes. Prentice Hall International Series in Computer Science. ISBN 978-0131532717 (hardback) or ISBN 978-0131532892 (paperback). (Available online at http://www.usingcsp.com/ in PDF format.)
Hoare, C. A. R. (1989). C. B., Jones (ed.). Essays in computing science. Prentice Hall International Series in Computer Science. ISBN 978-0-13-284027-9.
Hoare, C. A. R.; Gordon, M. J. C. (1992). Mechanised Reasoning and Hardware Design. Prentice Hall International Series in Computer Science. ISBN 978-0-13-572405-7. OCLC 25712842.
^Sampaio, Augusto (1993). An algebraic approach to compiler design. bodleian.ox.ac.uk (DPhil thesis). University of Oxford. OCLC 854973008. EThOS uk.bl.ethos.334903.[permanent dead link]
^ abc"List of Fellows". Archived from the original on 8 June 2016. Retrieved 17 October 2014.
^"Birthdays Jan 10". The Times. London. 10 January 2009. Retrieved 9 January 2010.
^Shustek, L. (2009). "Interview: An interview with C.A.R. Hoare". Communications of the ACM. 52 (3): 38–41. doi:10.1145/1467247.1467261. S2CID 1868477.
^Hoare, C. A. R. (1974). "Monitors: An operating system structuring concept". Communications of the ACM. 17 (10): 549–557. doi:10.1145/355620.361161. S2CID 1005769.
^Bowen, Jonathan (8 September 2006). Oral History of Sir Antony Hoare. Hoare (Sir Antony, C.A.R.) Oral History, CHM Reference number: X3698.2007 (Report). Computer History Museum. Archived from the original on 3 July 2013. Retrieved 18 April 2014.{{cite report}}: CS1 maint: bot: original URL status unknown (link)
^Lean, Thomas (2011). "Professor Sir Tony Hoare" (PDF). National Life Stories: An Oral History of British Science. UK: British Library. Archived (PDF) from the original on 15 September 2014. Retrieved 15 September 2014.
^ abcdeLevens, R.G.C., ed. (1964). Merton College Register 1900-1964. Oxford: Basil Blackwell. p. 434.
^ abHoare, Tony (Autumn 2009). "My Early Days at Elliotts". Resurrection (48). ISSN 0958-7403. Retrieved 27 May 2014.
^Roscoe, Bill; Jones, Cliff (2010). "1 Insight, inspiration and collaboration" (PDF). Reflections on the Work of C.A.R. Hoare. Springer. ISBN 978-1-84882-911-4. Archived (PDF) from the original on 9 October 2022.
^ abHoare, C.A.R. (February 1981). "The emperor's old clothes". Communications of the ACM. 24 (2): 5–83. doi:10.1145/358549.358561. ISSN 0001-0782.
^Hoare, C. A. R. (1981). "The emperor's old clothes". Communications of the ACM. 24 (2): 75–83. doi:10.1145/358549.358561.
^Jeuring, Johan; Meertens, Lambert; Guttmann, Walter (17 August 2016). "Profile of IFIP Working Group 2.1". Foswiki. Retrieved 7 October 2020.
^Swierstra, Doaitse; Gibbons, Jeremy; Meertens, Lambert (2 March 2011). "ScopeEtc: IFIP21: Foswiki". Foswiki. Retrieved 7 October 2020.
^Oral history interview with C. A. R. Hoare at Charles Babbage Institute, University of Minnesota, Minneapolis.
^The classic article on monitors – The original article on monitors
^"Preface to the ACM Turing Award lecture" (PDF). Archived from the original (PDF) on 19 April 2012.
^"C. Antony (Tony) R. Hoare". Archived from the original on 1 July 2012.
^Hoare, Tony (25 August 2009). "Null References: The Billion Dollar Mistake". InfoQ.com.
^"Null: The Billion Dollar Mistake". hashnode.com. 3 September 2020.
^
Hoare, Tony (2009). "Null References: The Billion Dollar Mistake" (Presentation abstract). QCon London. Archived from the original on 28 June 2009.
^Hoare, C. A. R. (1996). "Unification of Theories: A Challenge for Computing Science". Selected papers from the 11th Workshop on Specification of Abstract Data Types Joint with the 8th COMPASS Workshop on Recent Trends in Data Type Specification. Springer-Verlag. pp. 49–57. ISBN 3-540-61629-2.
^"ACM Programming Systems and Languages Paper Award". Association for Computing Machinery. 1973. Retrieved 7 July 2022.
^Hoare, C.A.R. (1972). "Proof of correctness of data representations". Communications of the ACM. 1 (4): 271–281. doi:10.1007/BF00289507. S2CID 34414224.
^Hoare, Charles Anthony Richard (27 October 1980). "The Emperor's Old Clothes: The 1980 ACM Turing Award Lecture" (PDF). Association for Computing Machinery. Archived from the original (PDF) on 19 April 2012.
^Anon (1982). "Anthony Hoare FRS". royalsociety.org. London: Royal Society.
^"Honorary Graduates 1989 to present". bath.ac.uk. University of Bath. Archived from the original on 17 July 2010. Retrieved 18 February 2012.
^"(Charles) Antony Richard (Tony) Hoare Biography". Archived from the original on 17 July 2014.
^"Sir Antony Hoare: 2006 Fellow". Archived from the original on 3 April 2015. Retrieved 8 March 2020."Sir Antony Hoare | Computer History Museum". Archived from the original on 3 April 2015. Retrieved 22 April 2015.
^"Annual Review 2007: Principal's Review". www1.hw.ac.uk. Archived from the original on 5 March 2016. Retrieved 29 March 2016.
^"Preisverleihung auf der Festveranstaltung "40 Jahre Informatik in München": TU München vergibt Friedrich L. Bauer-Preis an Tony Hoare" (in German). Technical University of Munich. 26 October 2007. Archived from the original on 10 June 2016. Retrieved 14 May 2016.
^"Programming Languages Achievement Award 2011". ACM. Retrieved 28 August 2012.
^"IEEE John von Neumann Medal Recipients" (PDF). IEEE. Archived (PDF) from the original on 9 October 2022. Retrieved 26 February 2011.
^Krzysztof, Diks (15 November 2012). "Profesor Hoare doktorem honoris causa Uniwersytetu Warszawskiego" (in Polish). University of Warsaw. Archived from the original on 26 August 2014. Retrieved 26 November 2012.
^"Los informáticos Tony Hoare y Mateo Valero serán investidos hoy doctores honoris causa por la Complutense" (in Spanish). 10 May 2013. Retrieved 10 May 2013.
^Jones, Cliff; Roscoe, A. W.; Wood, Kenneth R., eds. (2010). Reflections on the Work of C.A.R. Hoare. Springer Science. p. 3. Bibcode:2010rwch.book.....R.
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