factor/library/tools/inference.factor

179 lines
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Factor

! :folding=indent:collapseFolds=1:
! $Id$
!
! Copyright (C) 2004 Slava Pestov.
!
! Redistribution and use in source and binary forms, with or without
! modification, are permitted provided that the following conditions are met:
!
! 1. Redistributions of source code must retain the above copyright notice,
! this list of conditions and the following disclaimer.
!
! 2. Redistributions in binary form must reproduce the above copyright notice,
! this list of conditions and the following disclaimer in the documentation
! and/or other materials provided with the distribution.
!
! THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
! INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
! DEVELOPERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
! SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
! OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
! WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
! OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
! ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
IN: inference
USE: combinators
USE: errors
USE: interpreter
USE: kernel
USE: lists
USE: math
USE: namespaces
USE: stack
USE: strings
USE: vectors
USE: words
! Word properties that affect inference:
! - infer-effect -- must be set. controls number of inputs
! expected, and number of outputs produced.
! - meta-infer -- evaluate word in meta-interpreter if set.
! - infer - quotation with custom inference behavior; ifte uses
! this. Word is passed on the stack.
SYMBOL: d-in
SYMBOL: r-in
: gensym-vector ( n -- vector )
dup <vector> swap [ gensym over vector-push ] times ;
: inputs ( count stack -- stack )
#! Add this many inputs to the given stack.
>r dup d-in +@ gensym-vector dup r> vector-append ;
: ensure ( count stack -- stack )
#! Ensure stack has this many elements.
2dup vector-length > [
[ vector-length - ] keep inputs
] [
nip
] ifte ;
: ensure-d ( count -- )
#! Ensure count of unknown results are on the stack.
meta-d get ensure meta-d set ;
: consume-d ( count -- )
#! Remove count of elements.
[ pop-d drop ] times ;
: produce-d ( count -- )
#! Push count of unknown results.
[ gensym push-d ] times ;
: standard-effect ( word [ in | out ] -- )
over "meta-infer" word-property [
drop host-word
] [
unswons consume-d produce-d drop
] ifte ;
: apply-effect ( word [ in | out ] -- )
#! Helper word for apply-word.
dup car ensure-d
over "infer" word-property dup [
nip nip call
] [
drop standard-effect
] ifte ;
: no-effect ( word -- )
"Unknown stack effect: " swap word-name cat2 throw ;
DEFER: (infer)
: apply-word ( word -- )
#! Apply the word's stack effect to the inferencer's state.
dup "infer-effect" word-property dup [
apply-effect
] [
drop dup compound? [
word-parameter (infer)
] [
drop no-effect
] ifte
] ifte ;
: init-inference ( -- )
init-interpreter
0 d-in set
0 r-in set ;
: effect ( -- [ in | out ] )
#! After inference is finished, collect information.
d-in get meta-d get vector-length cons ;
: (infer) ( quot -- )
[ dup word? [ apply-word ] [ push-d ] ifte ] each ;
: infer ( quot -- [ in | out ] )
#! Stack effect of a quotation.
[ init-inference (infer) effect ] with-scope ;
: infer-branch ( quot -- in-d datastack )
[
copy-interpreter (infer)
d-in get meta-d get
] with-scope ;
: unify ( in stack in stack -- )
swapd 2dup vector-length= [
drop meta-d set
2dup = [
drop d-in set
] [
"Unbalanced ifte inputs" throw
] ifte
] [
"Unbalanced ifte outputs" throw
] ifte ;
: infer-ifte ( -- )
pop-d pop-d pop-d drop ( condition )
>r infer-branch r> infer-branch unify ;
\ call [ pop-d (infer) ] "infer" set-word-property
\ call [ 1 | 0 ] "infer-effect" set-word-property
\ ifte [ 3 | 0 ] "infer-effect" set-word-property
\ ifte [ infer-ifte ] "infer" set-word-property
\ >r [ pop-d push-r ] "infer" set-word-property
\ >r [ 1 | 0 ] "infer-effect" set-word-property
\ r> [ pop-r push-d ] "infer" set-word-property
\ r> [ 0 | 1 ] "infer-effect" set-word-property
\ drop t "meta-infer" set-word-property
\ drop [ 1 | 0 ] "infer-effect" set-word-property
\ nip t "meta-infer" set-word-property
\ nip [ 2 | 1 ] "infer-effect" set-word-property
\ dup t "meta-infer" set-word-property
\ dup [ 1 | 2 ] "infer-effect" set-word-property
\ over t "meta-infer" set-word-property
\ over [ 2 | 3 ] "infer-effect" set-word-property
\ pick t "meta-infer" set-word-property
\ pick [ 3 | 4 ] "infer-effect" set-word-property
\ swap t "meta-infer" set-word-property
\ swap [ 2 | 2 ] "infer-effect" set-word-property
\ rot t "meta-infer" set-word-property
\ rot [ 3 | 3 ] "infer-effect" set-word-property
\ vector-nth [ 2 | 1 ] "infer-effect" set-word-property
\ set-vector-nth [ 3 | 0 ] "infer-effect" set-word-property
\ vector-length [ 1 | 1 ] "infer-effect" set-word-property
\ set-vector-length [ 2 | 0 ] "infer-effect" set-word-property