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Chapters: 1: Introduction 2: Simple example 3: Invocation 4: Finer Control 5: X-Y Plots 6: Contour Plots 7: Image Plots 8: Examples 9: Gri Commands 10: Programming 11: Environment 12: Emacs Mode 13: History 14: Installation 15: Gri Bugs 16: Test Suite 17: Gri in Press 18: Acknowledgments 19: License Indices: Concepts Commands Variables |
9.3.52: `
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`while .test.|{rpn ...}'
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Perform statements in loop while the value of `.test.' or the RPN
expression is nonzero. The end of the loop designated by a line
containing the words `end while'. The value `.test.' may be
an rpn expression. To leave the loop prematurely, use a `break'
statement. Upon encountering a `break' statement, Gri jumps to the
line immediately following the loop. If the `-chatty' option is
nonzero, a notification is printed every 1000 passes through the loop,
as a debugging measure to catch unintended infinite loops.
Examples:
while 1 show "This loops forever. Need to 'break'" end while |
while 1
read .x. .y.
if ..eof..
break
end if
draw symbol bullet at .x. .y.
end while
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.i.' as they range 0, 1,
..., 9. After exiting from the loop, `.i.' will equal 10. Be
careful to use the correct rpn greater-than test to avoid an
infinite loop.
.i. = 0
while {rpn .i. 10 >}
show .i.
.i. += 1
end while
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