DO_loops


FOR

  If you use FOR in the first line of a DO loop, you request a
  loop variables (var) to be incremented at each iteration of
  the loop. Hence you have to specify the name of the variable,
  its initial value, the increment and the final value.

var

  The name of the variable to be incremented at each iteration.
  You may also change the value of this variable during the
  loop yourself.

  This string should start with an alphabetic character, be at
  most 10 characters long and should not contain separators,
  algebraic operators or parentheses.

from

  The initial value of the loop variable. This may be an expression
  in terms of global variables.

step

  The increment of the loop variable. The increment may assume
  positive and negative values but also 0.

  This expression is evaluated anew each iteration.

  If no step size is indicated, a default value of 1 is assumed.

to

  For positive increments, the loop is left as soon as the loop
  variable exceeds this value. For negative increments, the loop
  is left as soon as the variable is less than to.

  This expression is evaluated anew each iteration.

while

  The while condition is evaluated after the loop variable, if
  used, has been incremented and before a new iteration begins.
  You have to ensure that while is assigned a value before you
  execute the loop. Iteration is left as soon as the condition
  fails to hold.

  This expression is evaluated anew each iteration.

until

  The until condition is evaluated at the end of each iteration
  and does not need to have a value before the DO loop. The
  loop variable is incremented for the next cycle before until
  is calculated. Iteration is left as soon as the condition holds.

LEAVE

  Causes iteration to stop, no matter the WHILE, UNTIL and TO
  conditions.

  You may specify as an argument the name of the loop variable
  associated with the loop you wish to leave.

ITERATE

  Causes the remaining part of this pass through the loop to be
  skipped. Execution resumes at the top of the loop.

  You may specify as an argument the name of the loop variable
  associated with the loop you wish to leave.

Keyword index. Formatted on 10/11/98.