refactor tag module

pull/150/head
Matthew Butterick 7 years ago
parent 8236e21318
commit 69a5db2cd7

@ -1 +1 @@
1501884297
1502063629

@ -3,53 +3,60 @@
(require txexpr/base racket/string racket/match)
(provide default-tag-function make-default-tag-function define-tag-function)
(define first car)
(define second cadr)
(define (parse-leading-attrs xs)
(match xs
[(cons (? txexpr-attrs? leading-attrs) tail) (values leading-attrs tail)]
[else (values null xs)]))
(define (parse-colon-attrs xs)
(define (colon-attr-name? x)
(and (symbol? x)
(let ([result (regexp-match #rx".*?(?=:$)" (symbol->string x))])
(and (pair? result) (string->symbol (car result))))))
(let parse-next ([xs xs][colon-attrs empty])
(match xs
[(list* (? colon-attr-name? name) (? string? val) xs)
(parse-next xs (cons (list (colon-attr-name? name) val) colon-attrs))]
[else (values colon-attrs xs)])))
(define (parse-kw-attrs kw-symbols-in kw-args)
(define kw-symbols (map (λ (kw) (string->symbol (string-trim (keyword->string kw) "#:"))) kw-symbols-in))
(map list kw-symbols kw-args))
(define (make-one-tag-function outer-kws outer-kw-args id)
(make-keyword-procedure
(λ (inner-kws inner-kw-args . xs)
;; Three possible sources of attrs:
;; 1) normal attrs, in a list at the front of the args
(let*-values ([(leading-attrs xs) (parse-leading-attrs xs)]
;; 2) colon attrs, using special 'key: "value" syntax, also at the front of the args
[(colon-attrs xs) (parse-colon-attrs xs)]
;; 3) keyword attrs
[(kw-attrs) (parse-kw-attrs (append outer-kws inner-kws) (append outer-kw-args inner-kw-args))])
;; construct the xexpr result "manually" (i.e., not with `make-txexpr` because it may not be a legit txexpr for now
;; (but it may become one through further processing, so no need to be finicky)
;; however, don't show empty attrs.
(define attrs (append kw-attrs colon-attrs leading-attrs))
(cons id (if (null? attrs)
xs
(cons attrs xs)))))))
(define default-tag-function
(make-keyword-procedure
(λ (outer-kws outer-kw-args . ids)
(define (make-one-tag id)
(make-keyword-procedure
(λ (inner-kws inner-kw-args . attrs+xs)
;; Three possible sources of attrs:
;; 1) normal attrs, in a list at the front of the args
;; 2) colon args, using special 'key: "value" syntax, also at the front of the args
;; 3) keyword args.
(define-values (leading-attrs xs) (if (and (pair? attrs+xs) (txexpr-attrs? (car attrs+xs)))
(values (car attrs+xs) (cdr attrs+xs))
(values null attrs+xs)))
(define-values (kws kw-args) (values (append outer-kws inner-kws) (append outer-kw-args inner-kw-args)))
(match-define (list colon-attrs ... body) (let parse-one-colon-attr ([xs xs])
(define (colon-attr-name? x) (let ([result (regexp-match #rx".*?(?=:$)" (symbol->string x))])
(and result (string->symbol (car result))))) ; return name or #f
(define maybe-attr-name (and (>= (length xs) 2)
(symbol? (first xs))
(string? (second xs)) ; accept strings only as attr value
(colon-attr-name? (first xs))))
(if maybe-attr-name
(let ([attr-name maybe-attr-name][attr-value (second xs)])
(cons (list attr-name attr-value) (parse-one-colon-attr (cddr xs))))
(list xs))))
(define kw-symbols (map (λ (kw) (string->symbol (string-trim (keyword->string kw) "#:"))) kws))
(define attrs (append (map list kw-symbols kw-args) colon-attrs leading-attrs))
;; construct the xexpr result "manually" (i.e., not with `make-txexpr` because it may not be a legit txexpr for now
;; (but it may become one through further processing, so no need to be finicky)
;; however, don't show empty attrs.
(list* id (if (null? attrs)
body
(list* attrs body))))))
(let ([tag-proc (apply compose1 (map make-one-tag ids))]
(let ([tag-proc (apply compose1 (for/list ([id (in-list ids)])
(make-one-tag-function outer-kws outer-kw-args id)))]
[tag-proc-name (string->symbol (format "pollen-tag:~a" (string-join (map symbol->string ids) "+")))])
(procedure-rename tag-proc tag-proc-name)))))
(define make-default-tag-function default-tag-function) ; bw compat
(module+ test
(require rackunit txexpr/check)
(define outerdiv (default-tag-function 'div #:class "outer" #:style "outer"))

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