racket/collects/stepper/private/macro-unwind.ss
2008-05-02 05:52:10 +00:00

338 lines
16 KiB
Scheme

(module macro-unwind scheme/base
(require (only-in syntax/kerncase kernel-syntax-case)
scheme/contract
scheme/list
"model-settings.ss"
"shared.ss"
#;(file "/Users/clements/clements/scheme-scraps/eli-debug.ss")
(for-syntax scheme/base))
(provide/contract [unwind (syntax? render-settings? . -> . syntax?)])
;
; ;;; ;; ;;; ;;; ; ;; ;;; ; ; ; ;; ; ; ; ; ; ;; ;;; ; ; ; ;; ;; ;
;; ;; ; ; ; ; ;; ; ; ; ; ;; ; ; ; ; ; ;; ; ; ;; ; ;; ; ; ;;
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
; ; ; ;;;; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ; ;;
; ; ; ;;;;; ;;; ; ;;; ;; ; ; ; ; ; ; ; ; ;;; ; ; ; ; ;; ;
;
; unwind takes a syntax object with a single highlight,
; and returns a list of syntax objects
(define (improper-member elt improper-list)
(cond [(pair? improper-list)
(or (eq? elt (car improper-list))
(improper-member elt (cdr improper-list)))]
[else
(eq? elt improper-list)]))
(define-syntax (noisy-and stx)
(syntax-case stx ()
[(_) #`#t]
[(_ a b ...)
(with-syntax ([inner (syntax/loc stx (noisy-and b ...))]
[error (syntax/loc #`a
(error 'noisy-and "and clause failed"))])
(syntax/loc stx (if a inner error)))]
[else
(error 'noisy-and "bad syntax for noisy-and")]))
;(->* (syntax? (listof syntax?))
; (syntax? (listof syntax?)))
(define (recur-on-pieces stx settings)
(if (pair? (syntax-e stx))
(datum->syntax
stx (syntax-pair-map (syntax-e stx) (lambda (stx) (unwind stx settings))) stx stx)
stx))
(define (fall-through stx settings)
(kernel-syntax-case stx #f
[id
(identifier? stx)
(or (stepper-syntax-property stx 'stepper-lifted-name)
stx)]
[(define-values dc ...)
(unwind-define stx settings)]
[(#%plain-app exp ...)
(recur-on-pieces #'(exp ...) settings)]
[(quote datum)
(if (symbol? #'datum)
stx
#'datum)]
[(let-values . rest)
(unwind-mz-let stx settings)]
[(letrec-values . rest)
(unwind-mz-let stx settings)]
[(#%plain-lambda . rest)
(recur-on-pieces #'(lambda . rest) settings)]
[(set! var rhs)
(with-syntax ([unwound-var (or (stepper-syntax-property
#`var 'stepper-lifted-name)
#`var)]
[unwound-body (unwind #`rhs settings)])
#`(set! unwound-var unwound-body))]
[else (recur-on-pieces stx settings)]))
(define (unwind stx settings)
(transfer-info
(let ([hint (stepper-syntax-property stx 'stepper-hint)])
(if (procedure? hint)
(hint stx (lambda (stx) (recur-on-pieces stx settings)))
(let ([process (case hint
[(comes-from-cond) unwind-cond]
[(comes-from-and) (unwind-and/or 'and)]
[(comes-from-or) (unwind-and/or 'or)]
[(comes-from-local) unwind-local]
[(comes-from-recur) unwind-recur]
[(comes-from-check-expect) unwind-check-expect]
[(comes-from-check-within) unwind-check-within]
[(comes-from-check-error) unwind-check-error]
;;[(comes-from-begin) unwind-begin]
[else fall-through])])
(process stx settings))))
stx))
(define (transfer-highlight from to)
(if (stepper-syntax-property from 'stepper-highlight)
(stepper-syntax-property to 'stepper-highlight #t)
to))
(define (unwind-recur stx settings)
;; if you use #%app, it gets captured here
(with-syntax ([(app-keywd letrec-term argval ...) stx])
(with-syntax ([(new-argval ...)
(map (lambda (argval) (unwind argval settings)) (syntax->list #`(argval ...)))])
(let ([unwound (unwind #`letrec-term settings)])
(syntax-case unwound (letrec lambda)
[(letrec ([loop-name (lambda (argname ...) . bodies)])
loop-name-2)
(unless (free-identifier=? #`loop-name #`loop-name-2)
(error "unexpected syntax for 'recur': ~v" stx))
(transfer-highlight
unwound
#`(recur loop-name ([argname new-argval] ...) . bodies))]
[else #`(#,unwound new-argval ...)])))))
(define (unwind-define stx settings)
(kernel-syntax-case stx #f
[(define-values (name . others) body)
(begin
(unless (null? (syntax-e #'others))
(error 'reconstruct
"reconstruct fails on multiple-values define: ~v\n"
(syntax->datum stx)))
(let* ([printed-name
(or (stepper-syntax-property #`name 'stepper-lifted-name)
(stepper-syntax-property #'name 'stepper-orig-name)
#'name)]
[unwound-body (unwind #'body settings)]
;; see notes in internal-docs.txt
[define-type (stepper-syntax-property
unwound-body 'stepper-define-type)])
(if define-type
(kernel-syntax-case
unwound-body #f
[(lambda arglist lam-body ...)
(case define-type
[(shortened-proc-define)
(let ([proc-define-name
(stepper-syntax-property
unwound-body
'stepper-proc-define-name)])
(if (or (free-identifier=? proc-define-name
#'name)
(and (stepper-syntax-property #'name
'stepper-orig-name)
(free-identifier=?
proc-define-name
(stepper-syntax-property
#'name 'stepper-orig-name))))
#`(define (#,printed-name . arglist)
lam-body ...)
#`(define #,printed-name
#,unwound-body)))]
[(lambda-define)
#`(define #,printed-name #,unwound-body)]
[else (error 'unwind-define
"unknown value for syntax property 'stepper-define-type: ~e"
define-type)])]
[else (error 'unwind-define
"expr with stepper-define-type is not a lambda: ~e"
(syntax->datum unwound-body))])
#`(define #,printed-name #,unwound-body))))]
[else (error 'unwind-define
"expression is not a define-values: ~e"
(syntax->datum stx))]))
(define (unwind-mz-let stx settings)
(with-syntax ([(label ([(var) rhs] ...) . bodies) stx])
(with-syntax ([(rhs2 ...) (map (lambda (rhs) (unwind rhs settings)) (syntax->list #'(rhs ...)))]
[new-label
(if (improper-member 'comes-from-let*
(stepper-syntax-property
stx 'stepper-hint))
#`let*
(case (syntax-e #'label)
[(let-values) #'let]
[(letrec-values) #'letrec]))]
[new-bodies (map (lambda (body) (unwind body settings)) (syntax->list #'bodies))])
;; is this let and the nested one part of a let*?
(syntax-case #`new-bodies (let*)
[((let* bindings inner-body ...))
(and
(improper-member 'comes-from-let*
(stepper-syntax-property stx 'stepper-hint))
(eq? (stepper-syntax-property stx 'stepper-source)
(stepper-syntax-property (car (syntax->list #`new-bodies))
'stepper-source))
(eq? (stepper-syntax-property stx 'stepper-position)
(stepper-syntax-property (car (syntax->list #`new-bodies))
'stepper-position)))
#`(let* #,(append (syntax->list #`([var rhs2] ...))
(syntax->list #`bindings))
inner-body ...)]
[else
#`(new-label ([var rhs2] ...) . new-bodies)]))))
(define (unwind-local stx settings)
(kernel-syntax-case stx #f
;; at least through intermediate, define-values may not occur in
;; local.
[(letrec-values ([vars exp] ...) body)
(with-syntax ([defns (map (lambda (def)
(unwind def settings))
(syntax->list
#`((define-values vars exp) ...)))])
#`(local defns #,(unwind #'body settings)))]
[else (error 'unwind-local
"expected a letrec-values, given: ~e"
(syntax->datum stx))]))
;(define (unwind-quasiquote-the-cons-application stx settings)
; (syntax-case (recur-on-pieces stx settings) ()
; [(#%app the-cons . rest)
; (syntax (cons . rest))]
; [else
; (error 'reconstruct
; "unexpected result for unwinding the-cons application")]))
(define (unwind-cond-clause stx test-stx result-stx settings)
(with-syntax ([new-test (if (stepper-syntax-property stx 'stepper-else)
#`else
(unwind test-stx settings))]
[result (unwind result-stx settings)])
#`(new-test result)))
(define (unwind-cond stx settings)
(let ([user-source (syntax-property stx 'user-source)]
[user-position (syntax-property stx 'user-position)])
(with-syntax
([clauses
(let loop ([stx stx])
(if (and (eq? user-source
(syntax-property stx 'user-source))
(eq? user-position
(syntax-property stx 'user-position)))
(syntax-case stx (if begin)
;; the else clause disappears when it's a
;; language-inserted else clause
[(if test result)
(list (unwind-cond-clause stx #`test #`result settings))]
[(if test result else-clause)
(cons (unwind-cond-clause stx #`test #`result settings)
(loop (syntax else-clause)))]
;; else clause appears momentarily in 'before,' even
;; though it's a 'skip-completely'
[(begin . rest) null]
[else-stx
(error 'unwind-cond
"expected an if, got: ~e"
(syntax->datum (syntax else-stx)))])
(error 'unwind-cond
"expected a cond clause expansion, got: ~e"
(syntax->datum stx))))])
(syntax (cond . clauses)))))
;; unused: the fake-exp begin takes care of this for us...
#;(define (unwind-begin stx settings)
(syntax-case stx (let-values)
[(let-values () body ...)
(with-syntax ([(new-body ...)
(map (lambda (body) (unwind body settings)) (syntax->list #`(body ...)))])
#`(begin new-body ...))]))
(define ((unwind-and/or label) stx settings)
(let ([user-source (syntax-property stx 'user-source)]
[user-position (syntax-property stx 'user-position)]
[clause-padder
(if (render-settings-true-false-printed? settings)
(case label [(and) #'true] [(or) #'false])
(case label [(and) #'#t] [(or) #'#f]))])
(with-syntax
([clauses
(append
(build-list (stepper-syntax-property
stx 'stepper-and/or-clauses-consumed)
(lambda (dc) clause-padder))
(let loop ([stx stx])
(if (and (eq? user-source
(syntax-property stx 'user-source))
(eq? user-position
(syntax-property stx 'user-position)))
(syntax-case stx (if)
[(if part-1 part-2 part-3)
(cons (unwind (syntax part-1) settings)
(case label
[(and) (loop (syntax part-2))]
[(or) (loop (syntax part-3))]
[else (error 'unwind-and/or
"unknown label ~a" label)]))]
[else
(error 'unwind-and/or
"syntax: ~a does not match and/or patterns"
(syntax->datum stx))])
null)))])
#`(#,label . clauses))))
(define (unwind-check-expect stx settings)
(kernel-syntax-case (fall-through stx settings) #f
[(c-e (lambda () a1) a2 a3 a4)
#`(check-expect a1 a2)]
[(dots1 actual dots2)
(and (eq? (syntax->datum #'dots1) '...)
(eq? (syntax->datum #'dots2) '...))
(with-syntax ([expected (unwind (third (stepper-syntax-property stx 'stepper-args-of-call)) settings)])
#`(check-expect actual expected))]
[any #`(c-e any) #;#`(check-expect )]))
(define (unwind-check-within stx settings)
(kernel-syntax-case (fall-through stx settings) #f
[(c-e (lambda () a1) a2 a3 a4 a5)
#`(check-within a1 a2 a3)]
[(dots1 actual dots2)
(and (eq? (syntax->datum #'dots1) '...)
(eq? (syntax->datum #'dots2) '...))
(let ([args-of-call (stepper-syntax-property stx 'stepper-args-of-call)])
(with-syntax ([expected (unwind (third args-of-call) settings)]
[within (unwind (fourth args-of-call) settings)])
#`(check-within actual expected within)))]
[any #`(c-e any) #;#`(check-expect )]))
(define (unwind-check-error stx settings)
(kernel-syntax-case (fall-through stx settings) #f
[(c-e (lambda () a1) a2 a3 a4)
#`(check-error a1 a2)]
[(dots1 actual dots2)
(and (eq? (syntax->datum #'dots1) '...)
(eq? (syntax->datum #'dots2) '...))
(let ([args-of-call (stepper-syntax-property stx 'stepper-args-of-call)])
(with-syntax ([expected (unwind (third args-of-call) settings)])
#`(check-error actual expected)))]
[any #`(c-e any) #;#`(check-expect )]))
)