TPK algorithm: Difference between revisions

Content deleted Content added
dates from the paper
move up the ALGOL 60 implementation, as it is from the paper itself (and not OR). It does seem redundant to have so many descriptions of the algorithm, but whatever. Remove comment about overflow.
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The algorithm reads eleven numbers from an input device, stores them in an array, and then processes them in reverse order, applying a user-defined function to each value and reporting either the value of the function or a message to the effect that the value has exceeded some threshold.
 
In the original paper, they gave the following example implementation "in a dialect of [[ALGOL 60]]":<ref name="edpl"/>
== Implementations ==
In the paper, which covered "roughly the first decade" of the development of high-level programming languages (from 1945 up to 1957), the authors implement this algorithm in [[Konrad Zuse]]'s [[Plankalkül]], in [[Herman Goldstine|Goldstine]] and [[John von Neumann|von Neumann]]'s [[Flowchart|flow diagrams]], in [[Haskell Curry]]'s proposed notation, in [[Short Code (computer language)|Short Code]] of [[John Mauchly]] and others, in the Intermediate Program Language of [[Arthur Burks]], in the notation of [[Heinz Rutishauser]], in the language and compiler by [[Corrado Böhm]] in 1951–52, in [[Autocode#Glennie's Autocode|Autocode]] of [[Alick Glennie]], in the [[A-0 System|A-2]] system of [[Grace Hopper]], in the [[Laning and Zierler system]], in the earliest proposed [[Fortran]] (1954) of [[John Backus]], in the [[Autocode#Mark 1 Autocode|Autocode]] for [[Manchester Mark 1|Mark 1]] by [[Tony Brooker]], in ПП-2 of [[Andrey Ershov]], in BACAIC of Mandalay Grems and R. E. Porter, in Kompiler 2 of A. Kenton Elsworth and others, in ADES of E. K. Blum, the Internal Translator of [[Alan Perlis]], in [[Fortran]] of John Backus, in [[ARITH-MATIC]] and [[MATH-MATIC]] from [[Grace Hopper]]'s lab, in the system of [[Friedrich L. Bauer|Bauer]] and [[Klaus Samelson|Samelson]], and (in addenda in 2003 and 2009) PACT I and TRANSCODE. They then describe what kind of arithmetic was available, and provide a subjective rating of these languages on parameters of "implementation", "readability", "control structures", "data structures", "machine independence" and "impact", besides mentioning what each was the first to do.<ref name="edpl"/>
 
=== Implementations in more recent languages ===
 
====[[ALGOL 60]] implementation====
<syntaxhighlight lang="Pascal" line>
TPK: begin integer i; real y; real array a[0:10];
real procedure f(t); real t; value t;
f := sqrt(abs(t)) + 5 *× t ^ 3;
for i := 0 step 1 until 10 do read(a[i]);
for i := 10 step -1 until 0 do
begin y := f(a[i]);
if y > 400 then write(i, "'TOO LARGE"')
else write(i, y);
end
end TPK.
</syntaxhighlight>
 
== Implementations ==
The problem with the usually specified function is that the term <code>5 * t ^ 3</code> gives overflows in almost all languages for very large negative values.
In the paper, which covered "roughly the first decade" of the development of high-level programming languages (from 1945 up to 1957), the authors implement this algorithm in [[Konrad Zuse]]'s [[Plankalkül]], in [[Herman Goldstine|Goldstine]] and [[John von Neumann|von Neumann]]'s [[Flowchart|flow diagrams]], in [[Haskell Curry]]'s proposed notation, in [[Short Code (computer language)|Short Code]] of [[John Mauchly]] and others, in the Intermediate Program Language of [[Arthur Burks]], in the notation of [[Heinz Rutishauser]], in the language and compiler by [[Corrado Böhm]] in 1951–52, in [[Autocode#Glennie's Autocode|Autocode]] of [[Alick Glennie]], in the [[A-0 System|A-2]] system of [[Grace Hopper]], in the [[Laning and Zierler system]], in the earliest proposed [[Fortran]] (1954) of [[John Backus]], in the [[Autocode#Mark 1 Autocode|Autocode]] for [[Manchester Mark 1|Mark 1]] by [[Tony Brooker]], in ПП-2 of [[Andrey Ershov]], in BACAIC of Mandalay Grems and R. E. Porter, in Kompiler 2 of A. Kenton Elsworth and others, in ADES of E. K. Blum, the Internal Translator of [[Alan Perlis]], in [[Fortran]] of John Backus, in [[ARITH-MATIC]] and [[MATH-MATIC]] from [[Grace Hopper]]'s lab, in the system of [[Friedrich L. Bauer|Bauer]] and [[Klaus Samelson|Samelson]], and (in addenda in 2003 and 2009) PACT I and TRANSCODE. They then describe what kind of arithmetic was available, and provide a subjective rating of these languages on parameters of "implementation", "readability", "control structures", "data structures", "machine independence" and "impact", besides mentioning what each was the first to do.<ref name="edpl"/>
 
=== Implementations in more recent languages ===
====[[C (programming language)|C]] implementation====
This shows a C implementation equivalent to the above ALGOL 60.