factor/basis/persistent/hashtables/nodes/bitmap/bitmap.factor

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2.2 KiB
Factor

! Based on Clojure's PersistentHashMap by Rich Hickey.
USING: math math.bitwise arrays kernel accessors locals sequences
sequences.private
persistent.sequences
persistent.hashtables.config
persistent.hashtables.nodes ;
IN: persistent.hashtables.nodes.bitmap
: index ( bit bitmap -- n ) [ 1 - ] dip bitand bit-count ; inline
M:: bitmap-node (entry-at) ( key hashcode bitmap-node -- entry )
bitmap-node shift>> :> shift
hashcode shift bitpos :> bit
bitmap-node bitmap>> :> bitmap
bitmap-node nodes>> :> nodes
bitmap bit bitand 0 eq? [ f ] [
key hashcode
bit bitmap index nodes nth-unsafe
(entry-at)
] if ;
M:: bitmap-node (new-at) ( shift value key hashcode bitmap-node -- node' added-leaf )
bitmap-node shift>> :> shift
hashcode shift bitpos :> bit
bitmap-node bitmap>> :> bitmap
bit bitmap index :> idx
bitmap-node nodes>> :> nodes
bitmap bit bitand 0 eq? [
value key hashcode <leaf-node> :> new-leaf
bitmap bit bitor
new-leaf idx nodes insert-nth
shift
<bitmap-node>
new-leaf
] [
idx nodes nth :> n
shift radix-bits + value key hashcode n (new-at) :> ( n' new-leaf )
n n' eq? [
bitmap-node
] [
bitmap
n' idx nodes new-nth
shift
<bitmap-node>
] if
new-leaf
] if ;
M:: bitmap-node (pluck-at) ( key hashcode bitmap-node -- node' )
hashcode bitmap-node shift>> bitpos :> bit
bitmap-node bitmap>> :> bitmap
bitmap-node nodes>> :> nodes
bitmap-node shift>> :> shift
bit bitmap bitand 0 eq? [ bitmap-node ] [
bit bitmap index :> idx
idx nodes nth-unsafe :> n
key hashcode n (pluck-at) :> n'
n n' eq? [
bitmap-node
] [
n' [
bitmap
n' idx nodes new-nth
shift
<bitmap-node>
] [
bitmap bit eq? [ f ] [
bitmap bit bitnot bitand
idx nodes remove-nth
shift
<bitmap-node>
] if
] if
] if
] if ;
M: bitmap-node >alist% ( node -- ) nodes>> >alist-each% ;