factor/basis/memoize/memoize.factor

76 lines
2.1 KiB
Factor

! Copyright (C) 2007, 2009 Slava Pestov, Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel hashtables sequences sequences.private arrays
words namespaces make parser math assocs effects definitions
quotations summary accessors fry ;
IN: memoize
<PRIVATE
! We can't use n*quot, narray and firstn from generalizations because
! they're macros, and macros use memoize!
: (n*quot) ( n quot -- quotquot )
<repetition> concat >quotation ;
: [nsequence] ( length exemplar -- quot )
[ [ [ 1 - ] keep ] dip '[ _ _ _ new-sequence ] ]
[ drop [ [ set-nth-unsafe ] 2keep [ 1 - ] dip ] (n*quot) ] 2bi
[ nip ] 3append ;
: [firstn] ( length -- quot )
[ 0 swap ] swap
[ [ nth-unsafe ] 2keep [ 1 + ] dip ] (n*quot)
[ 2drop ] 3append ;
: packer ( seq -- quot )
length dup 4 <=
[ { [ f ] [ ] [ 2array ] [ 3array ] [ 4array ] } nth ]
[ { } [nsequence] ] if ;
: unpacker ( seq -- quot )
length dup 4 <=
[ { [ drop ] [ ] [ first2 ] [ first3 ] [ first4 ] } nth ]
[ [firstn] ] if ;
: pack/unpack ( quot effect -- newquot )
[ in>> packer ] [ out>> unpacker ] bi surround ;
: unpack/pack ( quot effect -- newquot )
[ in>> unpacker ] [ out>> packer ] bi surround ;
: make-memoizer ( table quot effect -- quot )
[ unpack/pack '[ _ _ cache ] ] keep
pack/unpack ;
PRIVATE>
: define-memoized ( word quot effect -- )
[ drop "memo-quot" set-word-prop ]
[ 2drop H{ } clone "memoize" set-word-prop ]
[ [ [ dup "memoize" word-prop ] 2dip make-memoizer ] keep define-declared ]
3tri ;
SYNTAX: MEMO: (:) define-memoized ;
PREDICATE: memoized < word "memoize" word-prop ;
M: memoized definer drop \ MEMO: \ ; ;
M: memoized definition "memo-quot" word-prop ;
M: memoized reset-word
[ call-next-method ]
[ { "memoize" "memo-quot" } reset-props ]
bi ;
: memoize-quot ( quot effect -- memo-quot )
[ H{ } clone ] 2dip make-memoizer ;
: reset-memoized ( word -- )
"memoize" word-prop clear-assoc ;
: invalidate-memoized ( inputs... word -- )
[ stack-effect in>> packer call ] [ "memoize" word-prop delete-at ] bi ;
\ invalidate-memoized t "no-compile" set-word-prop