The bct module implements an unbalanced binary tree with the key and data cell based. The implementation is non-recursive.
include ffl/bct.fs include ffl/bci.fs include ffl/str.fs include ffl/enm.fs \ Example1: store mountain height in a binary tree with numerical keys \ The mountain enumeration begin-enumeration enum: MountEverest enum: MontBlanc enum: MountElbrus enum: Vaalserberg end-enumeration \ Create the binary tree on the heap and store it in the heights variable bct-new value heights \ Add the mountain heights in the tree; the key is the mountain enum value 8300 MountEverest heights bct-insert 4819 MontBlanc heights bct-insert 5642 MountElbrus heights bct-insert \ Find a mountain height in the tree MontBlanc heights bct-get [IF] .( Mount:mont blanc height:) . cr [ELSE] .( Mount:mont blanc not in tree.) cr [THEN] Vaalserberg heights bct-get [IF] .( Mount:vaalserber height:) . cr [ELSE] .( Mount:vaalserberg not in tree.) cr [THEN] \ Free the heights tree from the heap heights bct-free \ Example2: store mountain height in a binary tree with string keys \ Create the binary tree in the dictionary bct-create mountains \ Setup the compare word for comparing the mountain names : mount-compare ( str str - n = Compare the two mountain names ) str^ccompare ; ' mount-compare mountains bct-compare! \ Add the mountain heights to the binary tree; the key is the mountain name in a (unique) dynamic string 8300 str-new dup s" mount everest" rot str-set mountains bct-insert 4819 str-new dup s" mont blanc" rot str-set mountains bct-insert 5642 str-new dup s" mount elbrus" rot str-set mountains bct-insert \ Find a mountain height in the binary tree str-new value mount-name s" mont blanc" mount-name str-set mount-name mountains bct-get [IF] .( Mount:) mount-name str-get type .( height:) . cr [ELSE] .( Mount:) mount-name str-get type .( not in tree.) cr [THEN] s" vaalserberg" mount-name str-set mount-name mountains bct-get [IF] .( Mount:) mount-name str-get type .( height:) . cr [ELSE] .( Mount:) mount-name str-get type .( not in tree.) cr [THEN] \ Word for printing the mountain heights : mount-emit ( x x -- = Print mountain ) str-get type ." --> " . cr ; \ Print all mountain heights ' mount-emit mountains bct-execute \ Execute the word mount-emit for all entries in the tree \ Example binary tree iterator \ Create the tree iterator in the dictionary mountains bci-create mount-iter \ Create an iterator named mount-iter on the mountains tree \ Using the iterator mount-iter bci-first [IF] .( First mount:) mount-iter bci-key drop str-get type .( height:) . cr [ELSE] .( No first mountain.) cr [THEN] mount-iter bci-last [IF] .( Last mount:) mount-iter bci-key drop str-get type .( height:) . cr [ELSE] .( No last mountain.) cr [THEN] \ Cleanup the tree mountains bct-clear