USING: math persistent.hashtables.nodes ;

IN: persistent.hashtables

TUPLE: persistent-hash
{ root read-only initial: empty-node }
{ count fixnum read-only initial: 0 } ;

USING: accessors assocs make persistent.hashtables
persistent.hashtables.nodes ;

M: persistent-hash >alist [ root>> >alist% ] { } make ;

USING: assocs persistent.hashtables prettyprint.custom ;

M: persistent-hash >pprint-sequence >alist ;

USING: accessors assocs persistent.hashtables ;

M: persistent-hash assoc-size count>> ;

USING: accessors assocs kernel math persistent.hashtables
persistent.hashtables.nodes ;

M: persistent-hash at*
[ dup hashcode >fixnum ] [ root>> ] bi* (entry-at) dup
[ value>> t ] [ f ] if ;

USING: kernel persistent.hashtables ;

M: persistent-hash clone ;

USING: assocs kernel persistent.hashtables ;

M: persistent-hash equal?
over persistent-hash? [ assoc= ] [ 2drop f ] if ;

USING: assocs kernel persistent.hashtables ;

M: persistent-hash hashcode* nip assoc-size ;

USING: assocs persistent.hashtables sequences ;

M: persistent-hash keys >alist [ first ] map ;

USING: accessors kernel math persistent.assocs
persistent.hashtables persistent.hashtables.nodes ;

M: persistent-hash new-at
[
[ 0 ] 3dip [ dup hashcode >fixnum ] [ root>> ] bi*
(new-at) 1 0 ?
] [ count>> ] bi + persistent-hash boa ;

USING: accessors combinators kernel math persistent.assocs
persistent.hashtables persistent.hashtables.nodes ;

M: persistent-hash pluck-at
[ [ dup hashcode >fixnum ] [ root>> ] bi* (pluck-at) ] keep
{
{ [ 2dup root>> eq? ] [ nip ] }
{ [ over not ] [ 2drop PH{ } ] }
[ count>> 1 - persistent-hash boa ]
} cond ;

USING: persistent.hashtables prettyprint.custom ;

M: persistent-hash pprint* pprint-object ;

USING: kernel persistent.hashtables prettyprint.custom ;

M: persistent-hash pprint-delims drop \ PH{ \ } ;

USING: assocs persistent.hashtables sequences ;

M: persistent-hash values >alist [ second ] map ;