scribble-enhanced/graph/lib/low.rkt

785 lines
26 KiB
Racket

#lang typed/racket
(provide degub)
(: degub ( (T) ( T T)))
(define (degub x) (display "degub:") (displayln x) x)
;; ==== low/typed-untyped-module.rkt ====
(require typed/untyped-utils)
(provide half-typed-module typed/untyped-prefix define-modules)
;; half-typed-module
(define-syntax-rule (typed-module m typed-language untyped-language . body)
(module m typed-language . body))
(define-syntax-rule (untyped-module m typed-language untyped-language . body)
(module m untyped-language . body))
(define-typed/untyped-identifier half-typed-module typed-module untyped-module)
#| ;; test: should work in no-check but not in typed:
(half-typed-module moo typed/racket typed/racket/no-check
(: foo One)
(define foo 2))
|#
;; typed/untyped-prefix
(define-syntax-rule
(typed-typed/untyped-prefix [typed-prefix ...] [untyped-prefix ...] . rest)
(typed-prefix ... . rest))
(define-syntax-rule
(untyped-typed/untyped-prefix [typed-prefix ...] [untyped-prefix ...] . rest)
(untyped-prefix ... . rest))
(define-typed/untyped-identifier typed/untyped-prefix
typed-typed/untyped-prefix
untyped-typed/untyped-prefix)
#|
;; test: should work in no-check but not in typed:
(typed/untyped-prefix
[module moo2 typed/racket]
[module moo2 typed/racket/no-check]
(: foo One)
(define foo 2))
|#
;; define-modules
(define-syntax define-modules
(syntax-rules (no-submodule)
[(_ ([no-submodule] [name lang] ...) . body)
(begin (begin . body)
(module name lang . body) ...)]
[(_ ([name lang] ...) . body)
(begin (module name lang . body) ...)]))
#|
;; TODO: tests: test with a macro and check that we can use it in untyped.
;; TODO: tests: test with two mini-languages with different semantics for some
;; function.
(define-modules ([foo typed/racket] [foo-untyped typed/racket/no-check])
(provide x)
(: x (→ Syntax Syntax))
(define (x s) s))
(module test racket
(require (submod ".." foo-untyped))
(x #'a))
|#
;; ==== low/require-provide.rkt ====
(provide require/provide)
(define-syntax (require/provide stx)
(syntax-case stx ()
[(_ require-spec ...)
#'(begin
(require require-spec ...)
(provide (all-from-out require-spec ...)))]))
(module+ test
(require typed/rackunit)
(module ma typed/racket
(define require-provide-foo 7)
(provide require-provide-foo))
(module mb typed/racket
(require (submod ".." ".."))
(require/provide (submod ".." ma)))
(require 'mb)
(check-equal? require-provide-foo 7))
;; ==== low/define-syntax-parse.rkt ====
(require syntax/parse
syntax/parse/define)
(provide define-syntax/parse
λ/syntax-parse)
(begin-for-syntax
(require (for-syntax racket/base
racket/stxparam)
racket/stxparam)
(provide stx)
(define-syntax-parameter stx
(lambda (stx)
(raise-syntax-error (syntax-e stx)
"Can only be used in define-syntax/parse"))))
(define-simple-macro (define-syntax/parse (name . args) . body)
(define-syntax (name stx2)
(syntax-parameterize ([stx (make-rename-transformer #'stx2)])
(syntax-parse stx2
[(_ . args) . body]))))
(define-simple-macro (λ/syntax-parse args . body)
(λ (stx2)
;(syntax-parameterize ([stx (make-rename-transformer #'stx2)])
(syntax-parse stx2
[args . body])));)
;; If you include this as a file, you need to do:
;(begin-for-syntax (provide stx))
;; It's not provided by (all-from-out) :-(
;; ==== low/check-type-and-equal.rkt ====
(require ;"define-syntax-parse.rkt"
(for-syntax syntax/parse
syntax/parse/experimental/template)
typed/rackunit)
(provide check-equal:?)
;; TODO: this won't expand types in the ann.
(define-syntax/parse
(check-equal:? actual
(~optional (~seq (~datum :) type))
expected)
(template (check-equal? (?? (ann actual type) actual) expected)))
;; ==== low/typed-fixnum.rkt ===
(provide fxxor)
;; For fxxor, used to compute hashes.
;; The type obtained just by writing (require racket/fixnum) is wrong, so we get
;; a more precise one.
(require/typed racket/fixnum [(fxxor fxxor2) ( Fixnum Fixnum Fixnum)])
(: fxxor ( Fixnum * Fixnum))
(define (fxxor . args)
(foldl fxxor2 0 args))
(module+ test
(require typed/rackunit)
(check-equal? (fxxor2 13206 23715) 28469)
(check-equal? (fxxor 0) 0)
(check-equal? (fxxor 13206) 13206)
(check-equal? (fxxor 13206 23715 314576) 304101))
;; ==== Rest ====
(provide hash-set**
map+fold
cons→values
(rename-out [cons→values cons->values])
nameof
first-value second-value third-value fourth-value fifth-value
sixth-value seventh-value eighth-value ninth-value tenth-value
(rename-out [compose ])
stx-list
stx-e
stx-pair
;string-set!
;string-copy!
;string-fill!
with-output-file
in-tails
in-heads
in-split
in-split*
*in-split
my-in-syntax
indexof
Syntax-Listof
check-duplicate-identifiers
generate-temporary)
(require (for-syntax syntax/parse syntax/parse/experimental/template))
(: hash-set** ( (K V)
( (HashTable K V) (Listof (Pairof K V)) (HashTable K V))))
(define (hash-set** h l)
(if (null? l)
h
(hash-set** (hash-set h (caar l) (cdar l)) (cdr l))))
(define #:∀ (A B) (cons→values [x : (Pairof A B)]) (values (car x) (cdr x)))
(: map+fold ( (E R A) ( ( E A (values R A)) A (Listof E)
(Values (Listof R) A))))
(define (map+fold f init-acc lst)
(let ([result (foldl (λ ([item : E] [acc : (Pairof (Listof R) A)])
(let-values ([(item new-acc) (f item (cdr acc))])
(cons (cons item (car acc))
new-acc)))
(cons '() init-acc)
lst)])
(values (car result) (cdr result))))
(define-syntax-rule (nameof x) (begin x 'x))
(module+ test
(require typed/rackunit)
(let ((y 3))
(check-equal? (nameof y) 'y)))
;(define (raise-multi-syntax-error name message exprs)
;(let ([e (exn:fail:syntax "message"
; (current-continuation-marks)
; (list #'aaa #'bbb))])
; ((error-display-handler) (exn-message e) e))
(define-syntax-rule (λstx (param ...) body ...)
(λ (param ...)
(with-syntax ([param param] ...)
body ...)))
(module+ test
(require typed/rackunit)
(check-equal? (syntax->datum ((λstx (foo bar) #'(foo bar)) #'a #'b))
(syntax->datum #'(a b))))
(define-syntax-rule (define-value-getter name v ... last-v)
(define-syntax-rule (name expr)
(call-with-values (λ () expr) (λ (v ... last-v . rest) last-v))))
(define-value-getter first-value v1)
(define-value-getter second-value v1 v2)
(define-value-getter third-value v1 v2 v3)
(define-value-getter fourth-value v1 v2 v3 v4)
(define-value-getter fifth-value v1 v2 v3 v4 v5)
(define-value-getter sixth-value v1 v2 v3 v4 v5 v6)
(define-value-getter seventh-value v1 v2 v3 v4 v5 v6 v7)
(define-value-getter eighth-value v1 v2 v3 v4 v5 v6 v7 v8)
(define-value-getter ninth-value v1 v2 v3 v4 v5 v6 v7 v8 v9)
(define-value-getter tenth-value v1 v2 v3 v4 v5 v6 v7 v8 v9 v10)
(module+ test
(require typed/rackunit)
(check-equal? (first-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 1)
(check-equal? (second-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 2)
(check-equal? (third-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 3)
(check-equal? (fourth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 4)
(check-equal? (fifth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 5)
(check-equal? (sixth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 6)
(check-equal? (seventh-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 7)
(check-equal? (eighth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 8)
(check-equal? (ninth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 9)
(check-equal? (tenth-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 10))
(define-match-expander stx-list
(lambda (stx)
(syntax-case stx ()
[(_ pat ...)
#'(? syntax?
(app syntax->list (list pat ...)))])))
(module+ test
(require typed/rackunit)
(check-equal? (match #'(1 2 3) [(stx-list a b c) (list (syntax-e c)
(syntax-e b)
(syntax-e a))])
'(3 2 1))
(check-equal? (match #'(1 2 3)
[(stx-list a ...) (map (inst syntax-e Positive-Byte) a)])
'(1 2 3))
#;(check-equal? (match #`(1 . (2 3)) [(stx-list a b c) (list (syntax-e c)
(syntax-e b)
(syntax-e a))])
'(3 2 1)))
(define-match-expander stx-e
(lambda (stx)
(syntax-case stx ()
[(_ pat)
#'(? syntax?
(app syntax-e pat))])))
(module+ test
(require typed/rackunit)
(check-equal? (match #'x [(stx-e s) s]) 'x)
(check-equal? (match #'(x . y) [(stx-e (cons a b)) (cons (syntax-e b)
(syntax-e a))])
'(y . x)))
(define-match-expander stx-pair
(lambda (stx)
(syntax-case stx ()
[(_ pat-car pat-cdr)
#'(? syntax?
(app syntax-e (cons pat-car pat-cdr)))])))
(module+ test
(require typed/rackunit)
(check-equal? (match #'(x . y) [(stx-pair a b) (cons (syntax-e b)
(syntax-e a))])
'(y . x))
(check-equal? (match #'(x y z) [(stx-pair a b) (cons (map syntax->datum b)
(syntax->datum a))])
'((y z) . x)))
(define-syntax (string-set! stx)
(raise-syntax-error 'string-set! "Do not mutate strings." stx))
(define-syntax (string-copy! stx)
(raise-syntax-error 'string-copy! "Do not mutate strings." stx))
(define-syntax (string-fill! stx)
(raise-syntax-error 'string-fill! "Do not mutate strings." stx))
#|
(define-syntax (with-output-file stx)
(syntax-parse stx
[(_ filename:expr (~optional (~seq #:mode mode:expr))
(~optional (~seq #:exists exists:expr))
body ...)
(template (with-output-to-file filename
(λ () body ...)
(?? (?@ #:mode mode))
(?? (?@ #:exists exists))))]))
|#
(define-syntax (with-output-file stx)
(syntax-parse stx
[(_ [var:id filename:expr]
(~optional (~seq #:mode mode:expr))
(~optional (~seq #:exists exists:expr))
body ...)
(template (call-with-output-file filename
(λ (var) body ...)
(?? (?@ #:mode mode))
(?? (?@ #:exists exists))))]))
(: in-tails ( (T) ( (Listof T) (Listof (Pairof T (Listof T))))))
(define (in-tails l)
(if (null? l)
'()
(cons l (in-tails (cdr l)))))
(module+ test
(require typed/rackunit)
(check-equal? (for/list : (Listof (Listof Number))
([x : (Listof Number) (in-tails '(1 2 3 4 5))]) x)
'((1 2 3 4 5) (2 3 4 5) (3 4 5) (4 5) (5)))
(let ((l '(1 2 3 4 5)))
(check-true (eq? (caddr (for/list : (Listof (Listof Number))
([x : (Listof Number) (in-tails l)]) x))
(cddr l)))))
(: in-heads ( (T) ( (Listof T) (Listof (Pairof T (Listof T))))))
(define (in-heads l)
(: my-append1 ( (Listof T) T (Pairof T (Listof T))))
(define (my-append1 x y)
(if (null? x)
(list y)
(cons (car x) (my-append1 (cdr x) y))))
(define (on-heads/private [acc-head : (Listof T)] [l : (Listof T)])
: (Listof (Pairof T (Listof T)))
(if (null? l)
'()
(let ([new-head (my-append1 acc-head (car l))])
(cons new-head (on-heads/private new-head (cdr l))))))
(on-heads/private '() l))
(module+ test
(require typed/rackunit)
(check-equal? (for/list : (Listof (Listof Number))
([x : (Listof Number) (in-heads '(1 2 3 4 5))]) x)
'((1) (1 2) (1 2 3) (1 2 3 4) (1 2 3 4 5))))
;; Can't write the type of on-split, because typed/racket doesn't allow writing
;; (Sequenceof A B), just (Sequenceof A).
;; in-parallel's type has access to the multi-valued version of Sequenceof,
;; though, so we let typed/racket propagate the inferred type.
(define #:∀ (T) (in-split [l : (Listof T)])
(in-parallel (sequence-append (in-value '()) (in-heads l))
(sequence-append (in-tails l) (in-value '()))))
;; Same as in-split, but without the empty tail.
(define #:∀ (T) (in-split* [l : (Listof T)])
(in-parallel (sequence-append (in-value '()) (in-heads l))
(sequence-append (in-tails l))))
;; Same as in-split, but without the empty head.
(define #:∀ (T) (*in-split [l : (Listof T)])
(in-parallel (in-heads l)
(sequence-append (sequence-tail (in-tails l) 1) (in-value '()))))
(define #:∀ (T) (*in-split* [l : (Listof T)])
(in-parallel (in-heads l)
(sequence-tail (in-tails l) 1)))
(: indexof ( (A B) ( A (Listof B) ( A B Any) (U #f Integer))))
(define (indexof elt lst [compare equal?])
(let rec ([lst lst] [index 0])
(if (null? lst)
#f
(if (compare elt (car lst))
index
(rec (cdr lst) (+ index 1))))))
;; See also syntax-e, which does not flatten syntax pairs, and syntax->list,
;; which isn't correctly typed (won't take #'(a . (b c d e))).
(define-type (Syntax-Listof T)
(Rec R (Syntaxof (U Null
(Pairof T R)
(Listof T)))))
;; in-syntax is now provided by racket/sequence.
(: my-in-syntax ( (T) ( (Syntax-Listof T)
(Listof T))))
(define (my-in-syntax stx)
(let ((e (syntax-e stx)))
(if (null? e)
e
(if (syntax? (cdr e))
(cons (car e) (my-in-syntax (cdr e)))
e))))
(define (test-in-syntax)
; (ann `(,#'(a . b) ,#'(c . d))
; (Listof (Syntaxof (U (Pairof (Syntaxof 'a) (Syntaxof 'b))
; (Pairof (Syntaxof 'c) (Syntaxof 'c))))))
(my-in-syntax #'((a . b) (c . d)))
; (ann `(,#'a ,#'b ,#'c ,#'d ,#'e) (Listof (Syntaxof (U 'a 'b 'c 'd))))
(my-in-syntax #'(a . (b c d e)))
; (ann '() (Listof (Syntaxof Nothing)))
(my-in-syntax #'()))
(: check-duplicate-identifiers ( (Syntaxof (Listof (Syntaxof Symbol)))
Boolean))
(define (check-duplicate-identifiers ids)
(if (check-duplicate-identifier (my-in-syntax ids)) #t #f))
(require/typed racket/syntax [generate-temporary ( Syntax Identifier)])
(require syntax/parse/define)
(provide define-simple-macro)
(require racket/match)
(provide (all-from-out racket/match)
(rename-out [match-lambda match-λ]
[match-lambda* match-λ*]
[match-lambda** match-λ**]))
;; ==== ids.rkt ====
(define-modules ([no-submodule] [ids-untyped typed/racket/no-check])
(provide format-ids
hyphen-ids
format-temp-ids
#|t/gen-temp|#
define-temp-ids)
(require/typed racket/syntax
[format-id ( Syntax String (U String Identifier) *
Identifier)])
(require (only-in racket/syntax define/with-syntax)
(for-syntax racket/base
racket/syntax
syntax/parse))
;(require racket/sequence) ;; in-syntax
(require "sequences.rkt"
#|"../low.rkt"|#) ;; my-in-syntax
(define-type S-Id-List
(U String
Identifier
(Listof String)
(Listof Identifier)
(Syntaxof (Listof Identifier))))
(: format-ids ( (U Syntax ( (U String Identifier) * Syntax))
String
S-Id-List *
(Listof Identifier)))
(define (format-ids lex-ctx format . vs)
(let* ([seqs
(map (λ ([v : S-Id-List])
(cond
[(string? v) (in-cycle (in-value v))]
[(identifier? v) (in-cycle (in-value v))]
[(list? v) (in-list v)]
[else (in-list (syntax->list v))]))
vs)]
[justconstants (andmap (λ (x) (or (string? x) (identifier? x))) vs)]
[seqlst (apply sequence-list seqs)])
(for/list : (Listof Identifier)
([items seqlst]
[bound-length (if justconstants
(in-value 'yes)
(in-cycle (in-value 'no)))])
(apply format-id
(if (procedure? lex-ctx) (apply lex-ctx items) lex-ctx)
format
items))))
(: hyphen-ids ( (U Syntax ( (U String Identifier) * Syntax))
S-Id-List *
(Listof Identifier)))
(define (hyphen-ids lex-ctx . vs)
(apply format-ids
lex-ctx
(string-join (map (λ _ "~a") vs) "-")
vs))
(: format-temp-ids ( String
S-Id-List *
(Listof Identifier)))
(define (format-temp-ids format . vs)
;; Introduce the binding in a fresh scope.
(apply format-ids (λ _ ((make-syntax-introducer) #'())) format vs))
(define-syntax (define-temp-ids stx)
(syntax-parse stx
[(_ format (base:id (~literal ...)))
#:when (string? (syntax-e #'format))
(with-syntax ([pat (format-id #'base (syntax-e #'format) #'base)])
#'(define/with-syntax (pat (... ...))
(format-temp-ids format #'(base (... ...)))))]
[(_ name:expr format:expr . vs)
#`(define/with-syntax name (format-temp-ids format . vs))])))
(module+ test
(require ;(submod "..")
;"test-framework.rkt"
(for-syntax racket/syntax
(submod ".." ids-untyped)))
(check-equal? (format-ids #'a "~a-~a" #'() #'())
'())
(check-equal? (map syntax->datum
(format-ids #'a "~a-~a" #'(x1 x2 x3) #'(a b c)))
'(x1-a x2-b x3-c))
;; Since the presence of "Syntax" in the parameters list makes format-ids
;; require a chaperone contract instead of a flat contract, we can't run the
;; two tests below directly, we would need to require the untyped version of
;; this file, which causes a cycle in loading.
(define-syntax (test1 stx)
(syntax-case stx ()
[(_ (let1 d1) x y)
(begin
(define/with-syntax (foo-x foo-y)
(format-ids (λ (xy)
(if (string=? (symbol->string (syntax->datum xy))
"b")
stx
#'()))
"foo-~a"
#'(x y)))
#'(let1 d1 (let ((foo-b 2) (foo-c 'b)) (cons foo-x foo-y))))]))
(check-equal? (test1 (let ((foo-b 1) (foo-c 'a))) b c)
'(1 . b))
(define-syntax (fubar stx)
(define/with-syntax (v1 ...) #'(1 2 3))
(define/with-syntax (v2 ...) #'('a 'b 'c))
;; the resulting ab and ab should be distinct identifiers:
(define/with-syntax (id1 ...) (format-temp-ids "~a" #'(ab cd ab)))
(define/with-syntax (id2 ...) (format-temp-ids "~a" #'(ab cd ab)))
#'(let ([id1 v1] ...)
(let ([id2 v2] ...)
(list (cons id1 id2) ...))))
(check-equal? (fubar) '((1 . a) (2 . b) (3 . c))))
#|
(define-template-metafunction (t/gen-temp stx)
(syntax-parse stx
[(_ . id:id)
#:with (temp) (generate-temporaries #'(id))
#'temp]
[(_ id:id ...)
(generate-temporaries #'(id ...))]))
|#
;; ==== syntax.rkt ====
(provide stx-assoc cdr-stx-assoc)
#|
(require/typed syntax/stx
[stx-car (∀ (A B) (→ (Syntaxof (Pairof A B)) A))]
[stx-cdr (∀ (A B) (→ (Syntaxof (Pairof A B)) B))])
|#
(: stx-car ( (A B) ( (Syntaxof (Pairof A B)) A)))
(define (stx-car p) (car (syntax-e p)))
(: stx-cdr ( (A B) ( (Syntaxof (Pairof A B)) B)))
(define (stx-cdr p) (cdr (syntax-e p)))
; (require/typed racket/base [(assoc assoc3)
; (∀ (a b) (→ Any (Listof (Pairof a b))
; (U False (Pairof a b))))])
(require/typed racket/base
[(assoc assoc3)
( (a b c) (case→ [ Any
(Listof (Pairof a b))
(U False (Pairof a b))]
[-> c
(Listof (Pairof a b))
( c a Boolean)
(U False (Pairof a b))]))])
(: stx-assoc ( (T) (case→
( Identifier
(U (Syntaxof (Listof (Syntaxof (Pairof Identifier T))))
(Listof (Syntaxof (Pairof Identifier T))))
(U (Syntaxof (Pairof Identifier T)) #f))
( Identifier
(Listof (Pairof Identifier T))
(U (Pairof Identifier T) #f)))))
(define (stx-assoc id alist)
(let* ([e-alist (if (syntax? alist)
(syntax->list alist)
alist)]
[e-e-alist (cond
[(null? e-alist) '()]
[(syntax? (car e-alist))
(map (λ ([x : (Syntaxof (Pairof Identifier T))])
(cons (stx-car x) x))
e-alist)]
[else
(map (λ ([x : (Pairof Identifier T)])
(cons (car x) x))
e-alist)])]
[result (assoc3 id e-e-alist free-identifier=?)])
(if result (cdr result) #f)))
(: cdr-stx-assoc
( (T) (case→ ( Identifier
(U (Syntaxof (Listof (Syntaxof (Pairof Identifier T))))
(Listof (Syntaxof (Pairof Identifier T)))
(Listof (Pairof Identifier T)))
(U T #f)))))
(define (cdr-stx-assoc id alist)
(if (null? alist)
#f
;; The typechecker is not precise enough, and the code below does not work
;; if we factorize it: (if (and (list? alist) (syntax? (car alist))) … …)
(if (list? alist)
(if (syntax? (car alist))
(let ((res (stx-assoc id alist)))
(if res (stx-cdr res) #f))
(let ((res (stx-assoc id alist)))
(if res (cdr res) #f)))
(let ((res (stx-assoc id alist)))
(if res (stx-cdr res) #f)))))
;; ==== generate-indices ====
(: generate-indices ( (T) (case→ ( Integer (Syntax-Listof T)
(Listof Integer))
( (Syntax-Listof T)
(Listof Nonnegative-Integer)))))
(provide generate-indices)
(define generate-indices
(case-lambda
[(start stx)
(for/list ([v (my-in-syntax stx)]
[i (in-naturals start)])
i)]
[(stx)
(for/list ([v (my-in-syntax stx)]
[i : Nonnegative-Integer
(ann (in-naturals) (Sequenceof Nonnegative-Integer))])
i)]))
;; ==== set.rkt ====
(provide set-map→set)
(: set-map→set ( (e b) ( (Setof e) ( e b) (Setof b))))
(define (set-map→set s f) (list->set (set-map s f)))
;; ==== type-inference-helpers.rkt ====
#|
;; This does not work, in the end.
(provide imap)
(define-syntax (imap stx)
(syntax-parse stx
[(_ lst:expr var:id (~optional (~literal →)) . body)
#'(let ()
(define #:∀ (T) (inlined-map [l : (Listof T)])
(if (null? l)
'()
(cons (let ([var (car l)]) . body)
(inlined-map (cdr l)))))
(inlined-map lst))]))
|#
;; ==== percent.rkt ====
(provide % define%)
#|(define-syntax (% stx)
(syntax-parse stx #:literals (= → :)
[(_ (~seq (~or ((~and var (~not :)) ...)
(~seq (~and var (~not (~or = → :))) ...)) = expr)
...
(~optional (~literal →)) . body)
#'(let-values ([(var ...) expr] ...) . body)]))|#
(begin-for-syntax
(define-syntax-class %pat
(pattern v:id
#:with expanded #'v)
(pattern ()
#:with expanded #'(list))
(pattern (x:%pat . rest:%pat)
#:with expanded #'(cons x.expanded rest.expanded)))
(define-splicing-syntax-class %assignment
#:attributes ([pat.expanded 1] [expr 0])
#:literals (= )
(pattern (~seq (~and maybe-pat (~not (~or = ))) ... (~datum =) expr:expr)
#:with [pat:%pat ...] #'(maybe-pat ...))))
(define-syntax (% stx)
(syntax-parse stx #:literals (= )
[(_ :%assignment ... (~optional (~literal )) . body)
#'(match-let*-values ([(pat.expanded ...) expr] ...) . body)]))
(begin-for-syntax
(define-syntax-class typed-pat
(pattern [x:%pat (~literal :) type:expr]
#:with (tmp) (generate-temporaries #'(x))
#:with var-type #`[tmp : type]
#:with (expanded ...) #'([x.expanded tmp]))
(pattern x:id
#:with var-type #'x
#:with (expanded ...) #'())
(pattern x:%pat
#:with (tmp) (generate-temporaries #'(x))
#:with var-type #'tmp
#:with (expanded ...) #'([x.expanded tmp]))))
(define-syntax (define% stx)
(syntax-parse stx
[(_ (name param:typed-pat ...)
(~and (~seq ret ...) (~optional (~seq (~literal :) ret-type)))
. body)
(displayln #'(define (name param.var-type ...)
(match-let (param.expanded ... ...) ret ... . body)))
#'(define (name param.var-type ...)
(match-let (param.expanded ... ...) ret ... . body))]))
#|
(begin-for-syntax
(define-syntax-class λ%expr
(pattern e:id #:where (symbol->string e))
(pattern e)
(pattern (e . rest:λ%expr))))
(define-syntax (λ% stx)
(syntax-parse stx
[(_ expr )]))
|#
;; ==== end ====