trivial/vector.rkt
2016-03-01 10:49:35 -05:00

112 lines
3.0 KiB
Racket

#lang typed/racket/base
;; TODO integrate with trivial/math to get ints from identifiers
(provide
define-vector:
let-vector:
;vector-length:
vector-ref:
;vector-set!:
;vector-map:
;vector-append:
;vector->list
;; TODO and a few more
;; --- private
(for-syntax parse-vector-length)
)
;; -----------------------------------------------------------------------------
(require
(only-in racket/unsafe/ops
unsafe-vector-ref)
(for-syntax
typed/racket/base
syntax/id-table
syntax/parse
syntax/stx
))
;; =============================================================================
(define-for-syntax vector-length-key 'vector:length)
(define-for-syntax errloc-key 'vector:)
(define-for-syntax id+vector-length (make-free-id-table))
(begin-for-syntax (define-syntax-class literal-vector
#:attributes (vector-length)
(pattern [e* ...]
#:with len (parse-vector-length #'(e* ...))
#:when (syntax-e #'len)
#:attr vector-length #'len)
))
(define-syntax (define-vector: stx)
(syntax-parse stx
[(_ name:id v:literal-vector)
(free-id-table-set! id+vector-length
#'name
(syntax-e #'v.vector-length))
#'(define name v)]
[(_ e* ...)
#'(define e* ...)]))
(define-syntax (let-vector: stx)
(syntax-parse stx
[(_ ([name:id v:literal-vector]) e* ...)
#'(let ([name v])
(let-syntax ([name (make-rename-transformer
(syntax-property #'name
vector-length-key
#'v.vector-length))])
e* ...))]
[(_ e* ...)
#'(let e* ...)]))
(define-for-syntax (vector-ref-error v i reason)
(raise-argument-error
errloc-key
(format "Index out-of-bounds: ~a" i)
v))
(define-syntax (vector-ref: stx)
(syntax-parse stx
[(_ v i:nat)
#:when (printf "ref: getting langth for ~a\n" (syntax->datum #'v))
#:with len (parse-vector-length #'v)
#:when (printf "ref: got langth ~a\n" (syntax->datum #'len))
#:when (syntax-e #'len)
(unless (< (syntax-e #'i) (syntax-e #'len))
(vector-ref-error (syntax-e #'v) (syntax-e #'i)))
(syntax/loc stx (unsafe-vector-ref v i))]
[(_ e* ...)
(syntax/loc stx (vector-ref e* ...))]))
;; -----------------------------------------------------------------------------
;; Assume `stx` is creating a vector; get the length of the vector to-be-made
(define-for-syntax (parse-vector-length stx)
(cond
[(syntax-property stx vector-length-key)
=> (lambda (x) x)]
[(identifier? stx)
(free-id-table-ref id+vector-length stx #f)]
[else
(syntax-parse stx #:literals (vector make-vector build-vector)
[(~or '#(e* ...)
#(e* ...)
;; TODO #{} #[] #6{} ...
(vector e* ...))
(length (syntax->list #'(e* ...)))]
[(make-vector n:nat e* ...)
(syntax-e #'n)]
[(build-vector n:nat f)
(syntax-e #'n)]
[_ #f])]))