> On Jul 18, 2015, at 1:34 PM, Mark Lawrence <breamore...@yahoo.co.uk> wrote: > >
[byte] > What is an {HP calculator} roll operation? > The original Hewlett Packard “Scientific” calculators (HP-35, 45, 65, etc) that used Polish notation (operand, operand, operation; with no “=“ sign) had a stack. That stack itself could be manipulated (e.g., interchange X and Y). One of the stack manipulation commands was “Roll” which moved the top entry into X and pushed remaining elements up one. Later versions had both Roll-up and Roll-down, Roll-down moved the X entry to the top of the stack and dropped the other elements. Bill (Who still uses an HP-45 emulator on his iPhone) > -- > My fellow Pythonistas, ask not what our language can do for you, ask > what you can do for our language. > > Mark Lawrence > > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list