HELP WHILE                                      Steven Hardy, January 1978

The syntax word WHILE provides one way of building a loop in POP-11. The
statement

    while <condition> do <actions> endwhile

evaluates the condition and if it is true executes the <actions>, then goes
back to test the condition again.  This iteration continues until the
condition is false, for example

    10 -> n;
    while n > 0 do
        ppr(n)
        n - 1 -> n
    endwhile;

will print out:

    10 9 8 7 6 5 4 3 2 1

The iteration can be terminated using any of
    * RETURN, * QUITLOOP,  *QUITIF,  * QUITUNLESS

or re-started using

    * NEXTLOOP, * NEXTIF, * NEXTUNLESS

See HELP
    *UNTIL    - like WHILE but repeats a set of actions UNTIL a condition
            is true
    *FOR   - iteration over numbers or structures
    *LOOPS    - for other types of iteration
    *CONTROL  - for an overview of control facilities

See also
REF * SYNTAX,  REF * POPSYNTAX

--- C.all/help/while ---------------------------------------------------
--- Copyright University of Sussex 1987. All rights reserved. ----------
