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typesetting/quad2/attr.rkt

147 lines
6.1 KiB
Racket

#lang debug racket/base
(require racket/match
racket/hash
racket/list
racket/string
racket/set
"dimension.rkt"
"pipeline.rkt"
"struct.rkt"
"constants.rkt"
"quad.rkt"
"param.rkt")
(provide (all-defined-out))
(define (do-attr-iteration qs
#:which-attr which-attr
#:attr-proc attr-proc)
(define attr-predicate
(match which-attr
[(? attr-key? attr-key) (λ (ak av) (eq? ak attr-key))]
[(? procedure? pred) (if (eq? 1 (procedure-arity pred))
(λ (ak _) (pred ak)) ; 1 arity implies key-only test
pred)]
[other (raise-argument-error 'do-attr-iteration "key predicate" other)]))
(define attrs-seen (mutable-seteq))
(let loop ([xs qs])
(for ([x (in-list xs)]
#:when (quad? x))
(let* ([q x]
[attrs (quad-attrs q)])
(unless (set-member? attrs-seen attrs)
(for ([(ak av) (in-hash attrs)]
#:when (attr-predicate ak av))
(hash-set! attrs ak (attr-proc ak av attrs)))
(set-add! attrs-seen attrs))
(loop (quad-elems q)))))
qs)
(define-pass (upgrade-attr-keys qs)
;; convert attr keys from symbols to attr struct types
;; also lets us validate keys strictly, if we want
#:pre (list-of quad?)
#:post (list-of quad?)
(define attr-lookup-table (for/hasheq ([a (in-list (current-attrs))])
(values (attr-key-name a) a)))
(define attrs-seen (mutable-seteq))
(define strict-attrs? (current-strict-attrs?))
(define (do-upgrade ak av attrs)
(cond
[(symbol? ak)
(match (hash-ref attr-lookup-table ak #false)
[(? attr-key? attr)
(hash-remove! attrs ak)
(hash-set! attrs attr av)]
[_ #:when strict-attrs?
(raise-argument-error 'upgrade-attr-keys "known attr" ak)]
[_ (void)])]
[else (raise-argument-error 'upgrade-attr-keys "symbol or attr" ak)]))
(do-attr-iteration qs
#:which-attr (λ (ak) (not (attr-key? ak)))
#:attr-proc do-upgrade))
(define-pass (downcase-attr-values qs)
;; make attribute values lowercase, unless they're case-sensitive
;; so we can check them more easily later.
;; in principle we could do this earlier and recursively process a single quad
;; rather than linearized quads
;; it would be faster because there are fewer copies of the attr hashes,
;; so we do fewer tests
;; but let's stay with the pipeline policy of operating on flat lists of quads
#:pre (list-of quad?)
#:post (list-of quad?)
(do-attr-iteration qs
#:which-attr attr-cased-string-key?
#:attr-proc (λ (ak av attrs) (string-downcase av))))
(define-pass (convert-boolean-attr-values qs)
#:pre (list-of quad?)
#:post (list-of quad?)
(do-attr-iteration qs
#:which-attr attr-boolean-key?
#:attr-proc (λ (ak av attrs) (match (string-downcase av)
["false" #false]
[_ #true]))))
(define-pass (convert-numeric-attr-values qs)
#:pre (list-of quad?)
#:post (list-of quad?)
(do-attr-iteration qs
#:which-attr attr-numeric-key?
#:attr-proc (λ (ak av attrs)
(cond
[(string->number av)]
[else
(raise-argument-error 'convert-numeric-attr-values "numeric string" av)]))))
(define-pass (complete-attr-paths qs)
#:pre (list-of quad?)
#:post (list-of quad?)
;; convert every pathlike thing to a complete path (well, path string, because it's inside an attr)
;; so we don't get tripped up later by relative paths
;; relies on `current-directory` being parameterized to source file's dir
(do-attr-iteration qs
#:which-attr attr-path-key?
#:attr-proc (λ (ak av attrs) (path->complete-path av))))
(define-pass (parse-dimension-strings qs)
#:pre (list-of quad?)
#:post (list-of quad?)
;; certain attributes can be "dimension strings", which are strings like "3in" or "4.2cm"
;; we parse them into the equivalent measurement in points.
(do-attr-iteration qs
#:which-attr attr-dimension-string-key?
#:attr-proc (λ (ak av attrs) (parse-dimension av attrs))))
(module+ test
(require rackunit)
(define-attr-list debug-attrs
[:foo (attr-cased-string-key 'foo)]
[:ps (attr-path-key 'ps)]
[:dim (attr-dimension-string-key 'dim)]
[:boolt (attr-boolean-key 'bool)]
[:boolf (attr-boolean-key 'bool)]
[:num (attr-numeric-key 'num)])
(parameterize ([current-attrs debug-attrs])
(define q (make-quad #:attrs (make-hasheq (list (cons :foo "BAR")
(cons 'ding "dong")
(cons :ps "file.txt")
(cons :dim "2in")
(cons :boolt "true")
(cons :boolf "false")
(cons :num "42.5")))))
(define qs (list q))
(check-not-exn (λ ()
(parameterize ([current-strict-attrs? #false])
(upgrade-attr-keys qs))))
(check-exn exn? (λ ()
(parameterize ([current-strict-attrs? #true])
(upgrade-attr-keys qs))))
(check-equal? (quad-ref (car (downcase-attr-values qs)) :foo) "bar")
(check-true (complete-path? (quad-ref (car (complete-attr-paths qs)) :ps)))
(check-equal? (quad-ref (car (parse-dimension-strings qs)) :dim) 144)
(let ([q (car (convert-boolean-attr-values qs))])
(check-true (quad-ref q :boolt))
(check-false (quad-ref q :boolf)))
(check-equal? (quad-ref (car (convert-numeric-attr-values qs)) :num) 42.5)))