racket/collects/macro-debugger/model/synth-derivs.ss
2007-11-15 18:37:40 +00:00

550 lines
23 KiB
Scheme

(module synth-derivs mzscheme
(require (lib "plt-match.ss")
(lib "list.ss")
"deriv.ss"
"deriv-util.ss"
"synth-engine.ss"
"stx-util.ss"
"context.ss")
(provide (all-defined))
;; check-nonlinear-subterms : (list-of Subterm) -> void
;; FIXME: No checking on renamings... need to add
;; Note: Make sure subterm contexts are *disjoint*, not just *distinct*
(define (check-nonlinear-subterms subterm-derivs)
(check-nonlinear-paths
(map s:subterm-path
(filter s:subterm? subterm-derivs))))
;; check-nonlinear-paths : (list-of Path) -> void
;; FIXME: This is overly conservative for now, but probably
;; okay given the way I construct paths.
(define (check-nonlinear-paths paths)
;; If there is a self path (null), then it must be the only path.
;; If there are any tail paths, there can be only one (too restrictive?),
;; and the number must be at least as high as any ref paths.
;; Group ref paths by number and recur
(define (tail-path? x) (and (pair? x) (tail? (car x))))
(define (ref-path? x) (and (pair? x) (ref? (car x))))
(let ([null-paths (filter null? paths)]
[tail-paths (filter tail-path? paths)]
[ref-paths (filter ref-path? paths)])
(when (and (pair? null-paths)
(or (> (length null-paths) 1)
(pair? tail-paths)
(pair? ref-paths)))
(raise (make nonlinearity #f paths)))
(when (pair? tail-paths)
(when (> (length tail-paths) 1)
(raise (make nonlinearity #f paths)))
(let ([n (tail-n (car (car tail-paths)))])
(for-each (lambda (p)
(when (> (ref-n (car p)) n)
(raise (make nonlinearity #f paths))))
ref-paths)))
(let ([ref-path-partitions (partition&cdr-ref-paths ref-paths)])
(for-each check-nonlinear-paths ref-path-partitions))))
;; partition&cdr-ref-paths : (list-of Path) -> (list-of (list-of Path))
(define (partition&cdr-ref-paths paths)
(let ([t (make-hash-table 'equal)]
[/null (lambda () null)])
(for-each (lambda (p)
(hash-table-put! t (ref-n (car p))
(cons (cdr p)
(hash-table-get t (ref-n (car p)) /null))))
paths)
(hash-table-map t (lambda (k v) v))))
;; substitute-subterms : Syntax (list-of Subterm) -> Syntax
;; - s:subterm contexts guaranteed to be disjoint.
;; - s:renames replace syntax with syntax of same structure
;; FIXME: Could do this more efficiently using the structure of contexts...
(define (substitute-subterms stx subterm-derivs)
(cond [(null? subterm-derivs)
stx]
[(s:subterm? (car subterm-derivs))
(let* ([subterm0 (car subterm-derivs)]
[path0 (s:subterm-path subterm0)]
[deriv0 (s:subterm-deriv subterm0)])
(let ([e2 (wderiv-e2 deriv0)])
(and e2
(substitute-subterms
(if path0 (path-replace stx path0 (wderiv-e2 deriv0)) stx)
(cdr subterm-derivs)))))]
[(s:rename? (car subterm-derivs))
(let ([subterm0 (car subterm-derivs)])
(substitute-subterms
(path-replace stx
(s:rename-path subterm0)
(s:rename-after subterm0))
(cdr subterm-derivs)))]
[else (error 'substitute-subterms "neither s:subterm nor s:rename")]))
;; wrap/rename : syntax (cons syntax syntax) WDeriv -> WDeriv
(define (wrap/rename e1 rename d)
(make p:rename e1 (wderiv-e2 d) null #f rename d))
;; wrap/rename-from : syntax WDeriv -> WDeriv
;; Wrap with renaming: given syntax to initial term of given deriv
(define (wrap/rename-from e0 d)
(if (eq? e0 (wderiv-e1 d))
d
(wrap/rename e0 (cons e0 (wderiv-e1 d)) d)))
;; combine-derivs : WDeriv WDeriv -> WDeriv
;; Adds the second derivation to the end of the first derivation.
;; Inserts a p:rename rule when the final syntax of the first derivation
;; is not identical to the initial syntax of the second.
(define (combine-derivs head tail)
;; head-loop : Derivation -> (values Derivation syntax)
(define (head-loop head)
(match head
[(Wrap mrule (e1 e2 tx next))
(recv [(next e2) (head-loop next)]
(values (make mrule e1 e2 tx next)
e2))]
[(Wrap p:variable (e1 e2 rs ?1))
(adjust-tail e2 rs)]
;; FIXME: appropriate?
[(Wrap p::STOP (e1 e2 rs ?1))
(adjust-tail e2 rs)]
[#f (values #f #f)]))
;; adjust-tail : syntax (list-of syntax) -> (values WDeriv syntax)
(define (adjust-tail head-e2 head-rs)
(match tail
[(Wrap deriv (e1 e2))
(values (if (eq? head-e2 e1)
tail
(wrap/rename-from head-e2 tail))
e2)]
[#f (values (make p:stop head-e2 head-e2 head-rs #f)
head-e2)]))
(recv [(d s) (head-loop head)]
d))
(define (combine/head e1 renames head next)
(wrap/rename e1 renames (combine-derivs head next)))
(define (reconstruct-defval/head e1 renames head dvvars dvrhs ?1)
(combine/head e1 renames head
(and dvrhs
(reconstruct-defval (wderiv-e2 head) dvvars dvrhs ?1))))
(define (reconstruct-defstx/head e1 renames head dsvars dsrhs ?1)
(combine/head e1 renames head
(and dsrhs
(reconstruct-defstx (wderiv-e2 head) dsvars dsrhs ?1))))
;; reconstruct-defval : syntax syntax WDeriv -> WDeriv
;; Reconstruct a define-values node from its rhs deriv
(define (reconstruct-defval head-e2 dvvars dvrhs ?1)
(if (not ?1)
(let-values ([(def1 def2 renames)
(reconstruct-definition-stxs head-e2 dvvars dvrhs)])
(wrap/rename head-e2 renames
(make p:define-values def1 def2 null #f dvrhs)))
(make p:define-values head-e2 #f null ?1 #f)))
;; reconstruct-defstx : syntax syntax Derivation -> Derivation
(define (reconstruct-defstx head-e2 dsvars bindrhs ?1)
(if (not ?1)
(match bindrhs
[(Wrap bind-syntaxes (rhs ?2))
(let-values ([(def1 def2 rename)
(reconstruct-definition-stxs head-e2 dsvars rhs)])
(wrap/rename head-e2 rename
(make p:define-syntaxes def1 def2 null #f rhs ?2)))])
(make p:define-syntaxes head-e2 #f null ?1 #f #f)))
;; reconstruct-definition-stxs : Syntax Syntax WDeriv -> Syntax Syntax Renames
(define (reconstruct-definition-stxs def0 vars rhs)
(let ([rhs-e1 (wderiv-e1 rhs)]
[rhs-e2 (wderiv-e2 rhs)])
(with-syntax ([(?define ?vars ?rhs) def0]
[?vars1 vars]
[?rhs1 rhs-e1])
(define def1
(syntax/skeleton def0 (?define ?vars1 ?rhs1)))
(define def2
(and rhs-e2
(with-syntax ([?rhs2 rhs-e2])
(syntax/skeleton def0 (?define ?vars1 ?rhs2)))))
(define the-rename
(cons (cons #'?vars #'?rhs)
(cons #'?vars1 #'?vars1)))
(define the-e1 def1)
(define the-e2 def2)
(values def1 def2 the-rename))))
(define (reconstruct-begin/head e1 renames head inners)
(let* ([inner-es1 (map wderiv-e1 inners)]
[inner-es2 (wderivlist-es2 inners)]
[e2 (and inner-es2
(with-syntax ([(?begin . ?inner-terms) (wderiv-e2 head)]
[?inner-terms* inner-es2])
(syntax/skeleton (wderiv-e2 head)
(?begin . ?inner-terms*))))])
(wrap/rename e1 renames
(combine-derivs
head
(make p:begin (wderiv-e2 head) e2 null #f
(make lderiv inner-es1 inner-es2 #f inners))))))
;; bderiv->lderiv : WBDeriv -> WLDeriv
;; Combines pass1 and pass2 into a single pass(2) list derivation
(define (bderiv->lderiv bd)
(match bd
[#f #f]
[(Wrap bderiv (es1 _es2 pass1 trans pass2))
(let-values ([(_dss dvs exprs)
(case trans
[(letrec)
(match pass2
[(Wrap lderiv (_ _ #f (list letrec-deriv)))
(decompose-letrec letrec-deriv)])]
[(list)
(match pass2
[(Wrap lderiv (_ _ #f derivs))
(values null null derivs)]
[#f
(values null null null)])])]
[(brules) pass1]
[(suffix) es1])
(let* ([derivs (brules->derivs brules es1 dvs exprs)]
[es2 (wderivlist-es2 derivs)])
(make lderiv es1 es2 #f derivs)))]))
(define (brules->derivs brules suffix dvs exprs)
;; take-expr : -> Derivation/#f
(define (take-expr)
(if (pair? exprs)
(begin0 (car exprs)
(set! exprs (cdr exprs)))
#f))
;; take-defval : -> (cons syntax Derivation) | #f
(define (take-defval)
(if (pair? dvs)
(begin0 (car dvs)
(set! dvs (cdr dvs)))
(cons #f #f)))
;; loop : number -> (list-of WDeriv)
;; brules, dvs, exprs, suffix threaded through, so use set!
;; dss are all trivial; fully expanded in pass 1
;; May not return all of 'count' items
(define (loop count)
(if (positive? count)
(match brules
[(list (and first (Wrap b:error (exn))))
(set! brules null)
(list (make p:unknown suffix #f null exn))]
[(cons (and first (Wrap b:defvals (renames head ?1))) next)
(let ([stx (stx-car suffix)]
[dv (take-defval)])
(set! suffix (stx-cdr suffix))
(set! brules next)
(cons (reconstruct-defval/head stx renames head
(car dv) (cdr dv) ?1)
(loop (sub1 count))))]
[(cons (and first (Wrap b:defstx (renames head ?1 bindrhs))) next)
(let ([stx (stx-car suffix)])
#;(set! _dss (cdr _dss))
(set! suffix (stx-cdr suffix))
(set! brules next)
(let ()
(define svars
(with-syntax ([(?ds ?svars . ?body) (cdr renames)])
#'?svars))
(define first*
(reconstruct-defstx/head stx renames head svars bindrhs ?1))
(cons first* (loop (sub1 count)))))]
[(cons (Wrap b:splice (renames head #f tail ?2)) next)
(let ([stx (stx-car suffix)]
[n (- (length (stx->list tail))
(length (stx->list (stx-cdr suffix))))])
(set! suffix tail)
(set! brules next)
;; When there's an error after the splice (empty begin),
;; then push it as a b:error in the remaining brules.
(when ?2 (set! brules (cons (make b:error ?2) brules)))
(let* ([splice-derivs (loop n)])
(cons (reconstruct-begin/head stx renames head splice-derivs)
(loop (sub1 count)))))]
[(list (Wrap b:splice (renames head (and exn? ?1) #f #f)))
(let ([stx (stx-car suffix)])
(set! suffix null)
(set! brules null)
(list (wrap/rename stx renames
(combine-derivs head
(make p:begin
(wderiv-e2 head) #f null ?1 #f)))))]
[(cons (and first (Wrap b:expr (renames head))) next)
(let ([stx (stx-car suffix)]
[expr1 (take-expr)])
(set! suffix (stx-cdr suffix))
(set! brules next)
(cons (wrap/rename stx renames (combine-derivs head expr1))
(loop (sub1 count))))]
['()
;; We've reached the end of pass1 processing.
;; We need to pull in exprs to fill out the begin/block shape.
(let* ([e1 (stx-car suffix)]
[expr1 (or (take-expr) (make p:stop e1 e1 null #f))]
[expr1-e1 (wderiv-e1 expr1)])
(set! suffix (stx-cdr suffix))
(cons (wrap/rename-from e1 expr1)
(loop (sub1 count))))])
;; Otherwise, we've reached the end, either locally or globally
null))
;; outer-loop : -> (list-of WDeriv)
(define (outer-loop)
(if (or (pair? brules) (not (stx-null? suffix)))
(append (loop 1) (outer-loop))
null))
#;(outer-loop)
;; FIXME: Need extra +1 in case of improper list?
(loop (stx-improper-length suffix)))
;; module-begin->lderiv : p:#%module-begin -> ??? ListDerivation
;; Only use when ?1 is #f.
(define (module-begin->lderiv pr)
(let-values ([(forms pass1 pass2)
(match pr
[(Wrap p:#%module-begin (e1 _ _ #f pass1 pass2 ?2))
(values (stx-cdr e1) pass1 pass2)])])
;; eat-skip : -> void
(define (eat-skip)
(match pass2
[(cons (struct mod:skip ()) next)
(set! pass2 next)]
[else (error 'eat-skip "expected skip!")]))
;; loop : number -> (list-of WDeriv)
;; NOTE: Definitely returns a list of <number> elements;
;; fills the end of the list with #f if necessary.
(define (loop count)
;(printf "** MB->L (~s)~n" count)
;(printf " forms: ~s~n" forms)
;(printf " pass1: ~s~n" pass1)
(if (positive? count)
(if (pair? pass1)
(loop-nz count)
(cons #f (loop (sub1 count))))
null))
;; loop-nz : number -> (list-of WDeriv)
(define (loop-nz count)
(match pass1
[(cons (Wrap mod:prim (head prim)) next)
(let ([form0 (stx-car forms)]
[pass1-part (car pass1)])
(set! forms (stx-cdr forms))
(set! pass1 next)
(let ([pass2-part (car (loop2 1))])
(cons (wrap/rename-from form0
(combine-prim pass1-part pass2-part))
(loop (sub1 count)))))]
[(cons (Wrap mod:splice (head ?1 tail)) next)
(let ([form0 (stx-car forms)]
[pass1-part (car pass1)])
(set! forms tail)
(set! pass1 next)
(if (not ?1)
(let ([inner-n (- (length (stx->list tail))
(length (stx->list (stx-cdr forms))))])
(let ([inners (loop inner-n)])
(cons (wrap/rename-from form0 (combine-begin head inners))
(loop (sub1 count)))))
(combine-derivs head
(make p:begin (wderiv-e2 head) #f null ?1 #f))))]
[(cons (Wrap mod:lift (head tail)) next)
(let ([form0 (stx-car forms)]
[inner-n (length (stx->list tail))])
(set! forms (stx-cdr forms))
(set! pass1 next)
(let ([inners (loop inner-n)])
(set! forms (cons (wderiv-e2 head) forms))
(let ([finish (car (loop 1))])
(cons (wrap/rename-from form0 (combine-lifts head finish inners))
(loop (sub1 count))))))]
[(cons (Wrap mod:lift-end (tail)) next)
;; FIXME
;; Best approach for now: just stop processing here.
(when (pair? next)
(warn 'hidden-lift-site/continuing))
(set! pass1 null)
(set! forms null)
null]))
;; loop2 : number -> (list-of WDeriv)
;; NOTE: Definitely returns a list of <number> elements;
;; fills the end of the list with #f if necessary.
(define (loop2 count)
;(printf "** loop2 (~s)~n" count)
;(printf " forms: ~s~n" forms)
;(printf " pass2: ~s~n" pass2)
(if (positive? count)
(match pass2
[(cons (Wrap mod:skip ()) next)
(set! pass2 next)
(cons #f (loop2 (sub1 count)))]
[(cons (Wrap mod:cons (deriv)) next)
(set! pass2 next)
(cons deriv (loop2 (sub1 count)))]
[(cons (Wrap mod:lift (deriv tail)) next)
(set! pass2 next)
(let* ([head-e1 (wderiv-e1 deriv)]
[head-e2 (wderiv-e2 deriv)]
[inner-n (length tail)]
[inners (loop2 inner-n)]
[inners-es1 (map wderiv-e1 inners)]
[inners-es2 (map wderiv-e2 inners)]
[inners-es2 (and (andmap syntax? inners-es2) inners-es2)]
[begin-stx1
(datum->syntax-object
#f
`(begin ,@inners-es1 ,(wderiv-e2 deriv)))]
[begin-stx2
(and inners-es2
(datum->syntax-object
#f `(begin ,@inners-es2 ,(wderiv-e2 deriv))))])
(eat-skip)
(cons
(make lift-deriv
head-e1 begin-stx2
deriv
begin-stx1
(make p:begin begin-stx1 begin-stx2 null #f
(make lderiv
(append inners-es1 (list head-e2))
(append inners-es2 (list head-e2))
#f
(append inners
(list (make p:stop head-e2 head-e2 null #f))))))
(loop2 (sub1 count))))]
['()
#;(printf "module-body->lderiv:loop2: unexpected null~n")
(cons #f (loop2 (sub1 count)))])
null))
(define (outer-loop)
(if (pair? pass1)
(append (loop 1) (outer-loop))
null))
(let* ([derivs (outer-loop)]
[es1 forms]
[es2 (wderivlist-es2 derivs)])
(make lderiv es1 es2 #f derivs))))
;; combine-prim : (W MBRule) WDeriv -> WDeriv
;; The MRule is always a mod:prim rule.
;; Need to insert a rename step in between...
(define (combine-prim mr deriv)
(let ([head (mod:prim-head mr)]
[pr (mod:prim-prim mr)])
(match pr
[(Wrap p:define-syntaxes (e1 e2 rs ?1 rhs ?2))
;; deriv is #f or trivial
(combine-derivs head pr)]
[(Wrap p:define-values (e1 e2 '() ?1 #f))
;; deriv is a pderiv for the entire define-values form
(combine-derivs head deriv)]
[#f
;; deriv is a complete derivation of the rest of the form
(combine-derivs head deriv)]
[(Wrap p::STOP (e1 e2 rs ?1))
;; deriv is #f
(combine-derivs head pr)])))
;; combine-begin : OkDeriv (list-of (W Deriv)) -> WDeriv
(define (combine-begin head inners)
(let* ([inners-es1 (map wderiv-e1 inners)]
[inners-es2 (wderivlist-es2 inners)]
[begin-e1 (wderiv-e2 head)]
[begin-e2 (and inners-es2
(with-syntax ([(?begin . _) begin-e1]
[inners-es1 inners-es1])
(syntax/skeleton begin-e1 (?begin . inners-es1))))])
(combine-derivs
head
(let ([ld (make lderiv inners-es1 inners-es2 #f inners)])
(make p:begin begin-e1 begin-e2 null #f ld)))))
;; combine-lifts : OkDeriv WDeriv (list-of WDeriv) -> WDeriv
(define (combine-lifts head finish inners)
(let* ([head-e1 (wderiv-e1 head)]
[head-e2 (wderiv-e2 head)]
[finish-e1 (wderiv-e1 finish)]
[finish-e2 (wderiv-e2 finish)]
[inners-es1 (map wderiv-e1 inners)]
[inners-es2 (wderivlist-es2 inners)])
(let ([begin-e1 #`(begin #,@inners-es1 #,head-e2)]
[begin-e2 (and inners-es2 finish-e2 #`(begin #,@inners-es2 #,finish-e2))])
(make lift-deriv head-e1 begin-e2
head
begin-e1
(make p:begin begin-e1 begin-e2 null #f
(make lderiv
(append inners-es1 (list head-e2))
(and inners-es2 finish-e2
(append inners-es2 (list finish-e2)))
#f
(append inners
(if inners-es2 (list finish) null))))))))
;; lderiv->module-begin : ListDerivation Syntax (list-of identifier) -> PRule
(define (lderiv->module-begin ld e1 rs)
(match ld
[(Wrap lderiv (inners-es1 inners-es2 ?1 inners))
(with-syntax ([(?module-begin . _) e1]
[inners-es1* inners-es1]
[inners-es2* inners-es2])
(make p:#%module-begin
(syntax/skeleton e1 (?module-begin . inners-es1*))
(syntax/skeleton e1 (?module-begin . inners-es2*))
rs
#f
(map (lambda (d) (make mod:cons d)) inners)
(map (lambda (x) (make mod:skip)) inners)
#f))]))
;; decompose-letrec : Derivation -> (list-of (cons Syntax Derivation))
;; (list-of (cons Syntax Derivation))
;; (list-of Derivation)
;; Extract the syntax RHS, value RHSs, and expression derivs
;; from a block-generated letrec-values or letrec-syntaxes form.
(define (decompose-letrec deriv)
(match deriv
[(Wrap p:letrec-syntaxes+values (_ _ _ #f srenames srhss vrenames vrhss body))
;; Assertion: pass1 of the body is always trivial
(with-syntax ([(([?svars ?srhs] ...) ([?vvars ?vrhs] ...) . ?body) srenames])
(with-syntax ([(([?vvars* ?vrhs*] ...) . ?body*)
(or vrenames #'(([?vvars ?vrhs] ...) . ?body))])
(values (map cons
(syntax->list #'(?svars ...))
srhss)
(map cons (syntax->list #'(?vvars* ...)) vrhss)
(lderiv-derivs (bderiv-pass2 body)))))]
[(Wrap p:letrec-values (_ _ _ #f vrenames vrhss body))
;; Assertion: pass1 of the body is always trivial
(with-syntax ([(([?vars ?rhs] ...) . ?body) vrenames])
(values null
(map cons (syntax->list #'(?vars ...)) vrhss)
(match body
[(Wrap bderiv (_ _ _pass1 _ (Wrap lderiv (_ _ ?1 derivs))))
derivs]
[#f
null])))]))
)