commit 4783c7f93e512193bf0691902c3120c2a6b66e67
parent cc3a224a7bd5565e4c6694a2ed94d1c1a911b92c
Author: Stephen Chang <stchang@ccs.neu.edu>
Date: Wed, 13 Aug 2014 16:39:16 -0400
sysf: copied from stlc
Diffstat:
| M | sysf.rkt | | | 168 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------ |
1 file changed, 118 insertions(+), 50 deletions(-)
diff --git a/sysf.rkt b/sysf.rkt
@@ -1,5 +1,6 @@
#lang racket/base
(require
+ racket/match
(for-syntax racket/base syntax/parse syntax/parse/experimental/template
racket/set syntax/id-table syntax/stx racket/list racket/syntax
"stx-utils.rkt")
@@ -9,28 +10,29 @@
(all-from-out racket/base)
λ #%app + #%datum let letrec cons null null? begin void
#%module-begin if
- ;#%top define
))
-
(provide
+ define-type cases
(rename-out
[λ/tc λ] [app/tc #%app] [let/tc let] [letrec/tc letrec]
[begin/tc begin] [void/tc void]
[if/tc if] [+/tc +]
- ;[top/tc #%top] [define/tc define]
[datum/tc #%datum] [module-begin/tc #%module-begin]
[cons/tc cons] [null/tc null] [null?/tc null?] [first/tc first] [rest/tc rest]))
-;; system f; extended from stlc.rkt 2014-08-08
-
-;; TODO:
-;; - type of top level (or module level) vars not checked
+;; System F (copied from stlc.rkt 2014-08-13)
+;;
+;; Features:
+;; - letrec
+;; - lists
+;; - user (recursive) function definitions
+;; - user (recursive) (variant) type-definitions
;; for types, just need the identifier bound
-(define-syntax-rule (define-type τ) (begin (define τ #f) (provide τ)))
-(define-syntax-rule (define-types τ ...) (begin (define-type τ) ...))
-(define-types Int String Bool → Listof Unit)
+(define-syntax-rule (define-builtin-type τ) (begin (define τ #f) (provide τ)))
+(define-syntax-rule (define-builtin-types τ ...) (begin (define-builtin-type τ) ...))
+(define-builtin-types Int String Bool → Listof Unit)
;; type environment
(begin-for-syntax
@@ -67,19 +69,19 @@
(define-syntax (check-type-error stx)
(syntax-parse stx
[(_ e)
- #:when (check-exn exn:fail? (λ () (local-expand #'e 'expression null)))
+ #:when (check-exn exn:fail? (λ () (expand/df #'e)))
#'(void)]))
(define-syntax (check-type stx)
(syntax-parse stx #:datum-literals (:)
[(_ e : τ)
- #:with e+ (local-expand #'e 'expression null)
+ #:with e+ (expand/df #'e)
#:when (check-true (assert-type #'e+ #'τ)
(format "Expected type ~a but got type ~a" #'τ (typeof #'e)))
#'(void)]))
(define-syntax (check-not-type stx)
(syntax-parse stx #:datum-literals (:)
[(_ e : τ)
- #:with e+ (local-expand #'e 'expression null)
+ #:with e+ (expand/df #'e)
#:when (check-false (type=? (typeof #'e+) #'τ)
(format "Expected type to not be ~a but got type ~a" #'τ (typeof #'e)))
#'(void)]))
@@ -150,17 +152,69 @@
[(_ x-τs e)
#'(parameterize ([Γ (type-env-extend x-τs)]) e)])))
+;; expand/df ------------------------------------------------------------------
;; depth-first expand
-(define-for-syntax (expand/df e)
- (if (identifier? e)
- (⊢ e (type-env-lookup e)) ; handle this here bc there's no #%var form
- (local-expand e 'expression null)))
+(define-for-syntax (expand/df e [ctx #f])
+; (printf "expanding: ~a\n" e)
+; (printf "typeenv: ~a\n" (Γ))
+ (cond
+ ;; 1st case handles struct constructors that are not the same name as struct
+ ;; (should always be an identifier)
+ [(syntax-property e 'constructor-for) => (λ (Cons)
+ (⊢ e (type-env-lookup Cons)))]
+ ;; 2nd case handles identifiers that are not struct constructors
+ [(identifier? e) (⊢ e (type-env-lookup e))] ; handle this here bc there's no #%var form
+ ;; local-expand must expand all the way down, ie have no stop-list, ie stop list can't be #f
+ ;; ow forms like lambda and app won't get properly assigned types
+ [else (local-expand e 'expression null ctx)]))
(define-for-syntax (expand/df/module-ctx def)
- (local-expand def 'module null))
+ (local-expand def 'module #f))
(define-for-syntax (expand/df/mb-ctx def)
- (local-expand def 'module-begin null))
+ (local-expand def 'module-begin #f))
+
+;; define-type ----------------------------------------------------------------
+(define-syntax (define-type stx)
+ (syntax-parse stx #:datum-literals (variant)
+ #;[(_ (Tycon:id X ...) (variant (Cons:id τ_fld ...) ...))
+ #:with ((x ...) ...) (stx-map generate-temporaries #'((τ_fld ...) ...))
+ #:when (Γ (type-env-extend #'([Cons (∀ (X ...) (→ τ_fld ... Tycon))] ...)))
+ #'(begin
+ (define-syntax (Tycon stx)
+ (syntax-parse stx
+ [(_ τ (... ...))
+ #:with (X ...) (τ (... ...))
+ #'(variant (Cons τ_fld ...) ...)]))
+ (struct Cons (x ...) #:transparent) ...)]
+ [(_ τ:id (variant (Cons:id τ_fld ...) ...))
+ #:with ((x ...) ...) (stx-map generate-temporaries #'((τ_fld ...) ...))
+ #:when (Γ (type-env-extend #'([Cons (→ τ_fld ... τ)] ...)))
+ #'(begin
+ (struct Cons (x ...) #:transparent) ...)]))
+(define-syntax (cases stx)
+ (syntax-parse stx
+ [(_ e [Cons (x ...) body ... body_result] ...)
+ #:with e+ (expand/df #'e)
+ #:with (Cons+ ...) (stx-map expand/df #'(Cons ...))
+ #:with ((→ τ ... τ_Cons) ...) (stx-map typeof #'(Cons+ ...))
+ #:when (stx-andmap (λ (τ) (assert-type #'e+ τ)) #'(τ_Cons ...))
+ #:with ((lam (x+ ...) body+ ... body_result+) ...)
+ (stx-map (λ (bods xs τs)
+ (with-extended-type-env
+ (stx-map list xs τs)
+ (expand/df #`(λ #,xs #,@bods))))
+ #'((body ... body_result) ...)
+ #'((x ...) ...)
+ #'((τ ...) ...))
+ #:when (stx-andmap (λ (bods) (stx-andmap assert-Unit-type bods)) #'((body+ ...) ...))
+ #:with (τ_result ...) (stx-map typeof #'(body_result+ ...))
+ #:when (or (null? (syntax->list #'(τ_result ...))) ; shouldnt happen
+ (andmap (λ (τ) (type=? τ (car (syntax->list #'(τ_result ...)))))
+ (cdr (syntax->list #'(τ_result ...)))))
+ (⊢ (syntax/loc stx (match e+ [(Cons+ x+ ...) body+ ... body_result+] ...))
+ (car (syntax->list #'(τ_result ...))))]))
+
;; typed forms ----------------------------------------------------------------
(define-syntax (datum/tc stx)
(syntax-parse stx
@@ -199,9 +253,7 @@
#:with (lam xs e+ ... e_result+) (with-extended-type-env #'([x τ] ...)
(expand/df #'(λ (x ...) e ... e_result)))
;; manually handle the implicit begin
- #:when (stx-map assert-Unit-type #'(e+ ...); [(_ x:id e)
-; #:with e))
-)
+ #:when (stx-map assert-Unit-type #'(e+ ...))
#:with τ_body (typeof #'e_result+)
(⊢ (syntax/loc stx (lam xs e+ ... e_result+)) #'(→ τ ... τ_body))]))
@@ -219,14 +271,8 @@
(define-syntax (letrec/tc stx)
(syntax-parse stx #:datum-literals (:)
[(_ ([f:id : τ_f e_f] ...) body ... body_result)
-; #:when (printf "letrec: ~a\n" (expand/df #'(letrec ([f e_f] ...) body ... body_result)))
- #:with (lrec ([(f+) e_f+] ...) body+ ... body_result+)
+ #:with (_ ([(f+) e_f+] ...) body+ ... body_result+)
(expand/df #'(letrec ([f e_f] ...) body ... body_result))
-; #:with (lam (f+ ...) e_f+ ...)
-; (expand/df #'(λ (f ...) e_f ...))
-; #:with (lam2 fs body+ ... body_result+)
-; (expand/df #'(λ (f ...) body ... body_result)) ; type env already extended by mod-beg
-; #:with τ_result (typeof #'body_result+)
(syntax/loc stx (letrec ([f+ e_f+] ...) body+ ... body_result+))]))
; #%app
@@ -293,48 +339,70 @@
#:with τ_result (typeof #'e_result+)
#:when (Γ (type-env-extend #'([f (→ τ ... τ_result)])))
(⊢ (syntax/loc stx (define (f x+ ...) e+ ... e_result+)) #'Unit)]
-; [(_ x:id e)
-; #:with e
))
-#;(define-syntax (top/tc stx)
- (syntax-parse stx
- [(_ . x:id)
- #:when (printf "top: ~a\n" #'x)
- #:with x+ (expand/df #'x)
- #:when (printf "expanded top: ~a\n" #'x+)
- (syntax/loc stx (#%top . x+))]))
(begin-for-syntax
- (define-syntax-class maybe-def #:datum-literals (: define)
+ (define-syntax-class maybe-def #:datum-literals (: define variant) #:literals (define-type)
(pattern (define (f:id [x:id : τx] ...) body ...)
#:with τ_result (generate-temporary #'f)
#:when (fvs (set-add (fvs) (syntax->datum #'τ_result)))
#:attr name #'(f)
#:attr val #'((λ/tc ([x : τx] ...) body ...))
#:attr τ #'((→ τx ... τ_result))
- #:attr e #'())
-; (pattern (define x:id exp:expr)
-; #:attr name #'(x)
-; #:attr val #'(exp)
-; #:attr τ ???
+ #:attr e #'() #:attr tydecl #'() #:attr names #'())
+ (pattern (define-type TypeName (variant (Cons fieldτ ...) ...))
+ #:attr name #'() #:attr τ #'() #:attr val #'() #:attr e #'()
+ #:attr tydecl #'((define-type TypeName (variant (Cons fieldτ ...) ...)))
+ #:attr names #'((Cons ...)))
(pattern exp:expr
- #:attr name #'() #:attr τ #'() #:attr val #'()
- #:attr e #'(exp))))
+ #:attr name #'() #:attr τ #'() #:attr val #'() #:attr tydecl #'() #:attr names #'()
+ #:attr e #'(exp)))
+ (define-syntax-class strct #:literals (begin define-values define-syntaxes)
+ (pattern
+ (begin
+ (define-values (x ...) mk-strct-type-def)
+ (define-syntaxes (y) strct-info-def))
+ #:attr def-val #'(define-values (x ...) mk-strct-type-def)
+ #:attr def-syn #'(define-syntaxes (y) strct-info-def)))
+ (define-syntax-class def-val #:literals (define-values)
+ (pattern
+ (define-values (x ...) mk-strct-type-def)
+ #:attr lhs #'(x ...)
+ #:attr rhs #'mk-strct-type-def))
+ (define-syntax-class def-syn #:literals (define-syntaxes)
+ (pattern
+ (define-syntaxes (x) strct-info-def)
+ #:attr lhs #'x
+ #:attr rhs #'strct-info-def))
+ )
(define-syntax (module-begin/tc stx)
- (syntax-parse stx
+ (syntax-parse stx #:literals (begin)
[(_ mb-form:maybe-def ...)
+ #:with (deftype ...) (template ((?@ . mb-form.tydecl) ...))
+ #:with ((begin deftype+ ...) ...) (stx-map expand/df/module-ctx #'(deftype ...))
+ #:with (structdef ...) (stx-flatten #'((deftype+ ...) ...))
+ #:with (structdef+:strct ...) (stx-map expand/df/module-ctx #'(structdef ...))
+ #:with (def-val:def-val ...) #'(structdef+.def-val ...)
+ #:with (def-val-lhs ...) #'(def-val.lhs ...)
+ #:with (def-val-rhs ...) #'(def-val.rhs ...)
+ #:with (def-syn:def-syn ...) #'(structdef+.def-syn ...)
+ #:with (def-syn-lhs ...) #'(def-syn.lhs ...)
+ #:with (def-syn-rhs ...) #'(def-syn.rhs ...)
#:with (f ...) (template ((?@ . mb-form.name) ...))
#:with (v ...) (template ((?@ . mb-form.val) ...))
#:with (τ ...) (template ((?@ . mb-form.τ) ...))
#:with (e ...) (template ((?@ . mb-form.e) ...))
#:when (Γ (type-env-extend #'([f τ] ...)))
- #:when (printf "fvs :~a\n" (fvs))
-; #:when (printf "mb: ~a\n" (syntax->datum (expand/df #'(letrec ([f v] ...) e ...))))
+; #:when (printf "fvs :~a\n" (fvs))
+;; NOTE: for struct def, define-values *must* come before define-syntaxes
+;; ow, error: "Just10: unbound identifier; also, no #%top syntax transformer is bound"
(quasisyntax/loc stx
(#%module-begin
- #,(expand/df #'(letrec/tc ([f : τ v] ...) e ... (void)))
+ #,(expand/df #'(let-values ([def-val-lhs def-val-rhs] ...)
+ (let-syntax ([def-syn-lhs def-syn-rhs] ...)
+ (letrec/tc ([f : τ v] ...) e ... (void)))))
(define #,(datum->syntax stx 'runtime-env)
(for/hash ([x:τ '#,(map (λ (xτ) (cons (car xτ) (syntax->datum (cdr xτ))))
(hash->list (do-subst (Γ))))])
