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Refactor section Stack Manipulation.

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HorseMD 2014-11-13 00:13:54 +00:00
parent ae2728d580
commit e5fbd94af0
1 changed files with 4 additions and 12 deletions
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forth.html.markdown
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@ -56,17 +56,10 @@ of what is written here should work elsewhere.
\ Naturally, as we do so much work with the stack, we'll want some useful methods.
drop \ drop (remove) the item at the top of the stack (note the difference between this and `.`)
dup \ duplicate the item on top the stack
rot \ rotate the top three items (third -> first, first -> second, second -> third)
swap \ swaps the top item with the second item
\ Examples:
dup * \ square the top item
2 5 dup * swap / \ half the top item squared
6 4 5 rot * - \ sometimes we just want to reorganize
4 0 drop 2 / \ add 4 and 0, remove 0 and divide the top by 2
3 dup - \ duplicate the top item (1st now equals 2nd): 3 - 3
2 5 swap / \ swap the top with the second element: 5 / 2
6 4 5 rot .s \ rotate the top 3 elements: 4 5 6 ok
4 0 drop 2 / \ remove the top item (dont print to screen): 4 / 2
\ ------------------------------ More Advanced Stack Manipulation ------------------------------
@ -173,7 +166,6 @@ mynumbers 3 cells erase
\ them to 0 we just use `erase`).
\ or we can just skip all the above and initialize with specific values:
create mynumbers 64 , 9001 , 1337 , \ the last `,` is important!
\ ...which is equivalent to: