Category:PL/0: Difference between revisions

'''PL/0''' is an educational programming language. It was originally introduced in the book, ''Algorithms + Data Structures = Programs'', by [[Niklaus Wirth]] in 1976. Wirth uses PL/0 as an example of how to construct a compiler. This language has littlesimple constructs. Writing real applications in PL/0 is not practical, but the compiler can remain compact and simple.

The only data type areis integer numbers. The only operators are arithmetical and comparison onescomparisons. There is a function <code>odd</code> which examines if theits integer argument is odd.

In the original implementation presented by Wirth, there are no input and output routines. The interpreter prints the new value of each variable when it becomes changedchanges. So, the program:

gives thethis output:

Due to typograhictypographic conventions, Wirth uses non-ASCII symbols <code>≠</code>, <code>≤</code>, and <code>≥</code>. Some implementations use <code>#</code> for "not equal", <code>[</code> for "less or equal", and <code>]</code> for "greater or equal".

Some implementations accept only upper-caseuppercase letters or only lower-caselowercase letters in keywords and identifiers.