racket/collects/syntax/private/stxparse/rep-patterns.ss
Ryan Culpepper 3e63caa887 merged changes from /branches/ryanc/sp2:
added syntax/parse library and documentation
  added syntax/id-table library and documentation

svn: r15376
2009-07-03 19:47:25 +00:00

148 lines
4.6 KiB
Scheme

#lang scheme/base
(require (for-syntax scheme/base
syntax/stx
"../util.ss"))
(provide (all-defined-out))
#|
A PBase/HPBase/EHPBase is (listof IAttr)
If P = (make-pattern Attrs ...) and A is in Attrs,
the depth of A is with respect to P,
not with respect to the entire enclosing pattern.
An IdPrefix is an identifier/#f
If #f, it means bind no attributes
If identifier, it already includes the colon part, unless epsilon
|#
#|
A SinglePattern is one of
(make-pat:name SPBase SinglePattern (listof identifier))
(make-pat:any SPBase)
(make-pat:sc SPBase id id boolean boolean)
(make-pat:datum SPBase datum)
(make-pat:literal SPBase identifier)
(make-pat:head SPBase HeadPattern SinglePattern)
(make-pat:dots SPBase (listof EllipsisHeadPattern) SinglePattern)
(make-pat:and SPBase (listof SinglePattern))
(make-pat:or SPBase (listof SinglePattern))
(make-pat:compound SPBase Kind (listof SinglePattern))
(make-pat:cut SPBase SinglePattern)
(make-pat:describe SPBase stx SinglePattern)
(make-pat:bind SPBase (listof clause:attr))
(make-pat:fail SPBase stx stx)
A ListPattern is a subtype of SinglePattern; one of
(make-pat:datum SPBase '())
(make-pat:head SPBase HeadPattern ListPattern)
(make-pat:compound SPBase '#:pair (list SinglePattern ListPattern))
(make-pat:dots SPBase EllipsisHeadPattern SinglePattern)
(make-pat:cut SPBase ListPattern)
|#
(define-struct pat:name (attrs pattern names) #:prefab)
(define-struct pat:any (attrs) #:prefab)
(define-struct pat:sc (attrs parser description bind-term? bind-attrs?) #:prefab)
(define-struct pat:datum (attrs datum) #:prefab)
(define-struct pat:literal (attrs id) #:prefab)
(define-struct pat:head (attrs head tail) #:prefab)
(define-struct pat:dots (attrs heads tail) #:prefab)
(define-struct pat:and (attrs patterns) #:prefab)
(define-struct pat:or (attrs patterns) #:prefab)
(define-struct pat:compound (attrs kind patterns) #:prefab)
(define-struct pat:cut (attrs pattern) #:prefab)
(define-struct pat:describe (attrs description pattern) #:prefab)
(define-struct pat:bind (attrs clauses) #:prefab)
(define-struct pat:fail (attrs when message) #:prefab)
#|
A HeadPattern is one of
(make-hpat:ssc HPBase id id boolean boolean)
(make-hpat:seq HPBase ListPattern)
(make-hpat:or HPBase (listof HeadPattern))
(make-hpat:describe HPBase stx/#f HeadPattern)
|#
(define-struct hpat:ssc (attrs parser description bind-term? bind-attrs?) #:prefab)
(define-struct hpat:seq (attrs inner) #:prefab)
(define-struct hpat:or (attrs patterns) #:prefab)
(define-struct hpat:describe (attrs description pattern) #:prefab)
#|
An EllipsisHeadPattern is
(make-ehpat EHPBase HeadPattern RepConstraint)
A RepConstraint is one of
(make-rep:once stx stx stx)
(make-rep:optional stx stx)
(make-rep:bounds nat/#f nat/#f stx stx stx)
#f
|#
(define-struct ehpat (attrs head repc) #:prefab)
(define-struct rep:once (name under-message over-message) #:prefab)
(define-struct rep:optional (name over-message) #:prefab)
(define-struct rep:bounds (min max name under-message over-message) #:prefab)
#|
A Kind is one of
'#:pair
'#:box
'#:vector
(list '#:pstruct prefab-struct-key)
|#
(define (pattern? x)
(or (pat:name? x)
(pat:any? x)
(pat:sc? x)
(pat:datum? x)
(pat:literal? x)
(pat:head? x)
(pat:dots? x)
(pat:and? x)
(pat:or? x)
(pat:compound? x)
(pat:cut? x)
(pat:describe? x)
(pat:bind? x)
(pat:fail? x)))
(define (head-pattern? x)
(or (hpat:ssc? x)
(hpat:seq? x)
(hpat:or? x)
(hpat:describe? x)))
(define (ellipsis-head-pattern? x)
(ehpat? x))
(define single-pattern? pattern?)
(define (single-or-head-pattern? x)
(or (single-pattern? x)
(head-pattern? x)))
(define pattern-attrs
(let ()
(define-syntax (mk-get-attrs stx)
(syntax-case stx ()
[(_ struct ...)
(with-syntax
([([pred accessor] ...)
(for/list ([s (stx->list #'(struct ...))])
(list (datum->syntax
s (format-symbol "~a?" (syntax-e s)))
(datum->syntax
s (format-symbol "~a-attrs" (syntax-e s)))))])
#'(lambda (x)
(cond [(pred x) (accessor x)] ...
[else (raise-type-error 'pattern-attrs "pattern" x)])))]))
(mk-get-attrs pat:name pat:any pat:sc pat:datum pat:literal pat:head
pat:dots pat:and pat:or pat:compound pat:cut pat:describe
pat:bind pat:fail
hpat:ssc hpat:seq hpat:or hpat:describe
ehpat)))