Tree traversal: Difference between revisions

=={{header|Quackery}}==

<lang Quackery>

[ this ] is nil ( --> [ )

[ ' [ 1

[ 2

[ 4

[ 7 nil nil ]

nil ]

[ 5 nil nil ] ]

[ 3

[ 6

[ 8 nil nil ]

[ 9 nil nil ] ]

nil ] ] ] is tree ( --> [ )

[ dup nil = iff drop done

unpack swap rot

echo sp

recurse

recurse ] is pre-order ( [ --> )

[ dup nil = iff drop done

unpack unrot

recurse

echo sp

recurse ] is in-order ( [ --> )

[ dup nil = iff drop done

unpack swap

recurse

recurse

echo sp ] is post-order ( [ --> )

[ stack [ ] ] is queue ( --> s )

[ queue share [] = ] is qempty ( --> b )

[ queue take

swap nested join

queue put ] is enqueue ( x --> )

[ queue take

behead swap

queue put ] is dequeue ( --> x )

[ enqueue

[ qempty not while

dequeue

dup nil = iff

drop again

unpack swap

enqueue

enqueue

echo sp again ] ] is level-order ( [ --> )

tree pre-order cr

tree in-order cr

tree post-order cr

tree level-order cr</lang>

{{out}}

<pre>1 2 4 7 5 3 6 8 9

7 4 2 5 1 8 6 9 3

7 4 5 2 8 9 6 3 1

1 2 3 4 5 6 7 8 9

</pre>