#lang typed/racket/base (require (for-syntax typed/racket/base racket/syntax racket/string)) (require/typed racket/list [empty? (All (A) ((Listof A) -> Boolean))] [last ((Listof Any) . -> . Any)] [flatten ((Listof Any) . -> . (Listof Any))]) (require/typed sugar/list [trimf (All (A) ((Listof A) (A . -> . Boolean) -> (Listof A)))] [filter-split (All (A) ((Listof A) (A . -> . Boolean) -> (Listof (Listof A))))]) (require/typed racket/string [string-append* ((Listof String) . -> . String)]) (require/typed sugar/string [ends-with? (String String . -> . Boolean)]) (require sugar/debug) (provide (all-defined-out)) (define-syntax (define/typed stx) (syntax-case stx () [(_ (proc-name arg ... . rest-arg) type-expr body ...) #'(define/typed proc-name type-expr (λ(arg ... . rest-arg) body ...))] [(_ proc-name type-expr body ...) #'(begin (: proc-name type-expr) (define proc-name body ...))])) (define-syntax (define/typed+provide stx) (syntax-case stx () [(_ (proc-name arg ... . rest-arg) type-expr body ...) #'(begin (provide proc-name) (define/typed proc-name type-expr (λ(arg ... . rest-arg) body ...)))] [(_ proc-name type-expr body ...) #'(begin (provide proc-name) (begin (: proc-name type-expr) (define proc-name body ...)))])) (define-syntax-rule (even-members xs) (for/list : (Listof Any) ([(x i) (in-indexed xs)] #:when (even? i)) x)) (define-type QuadName Symbol) (define-predicate QuadName? QuadName) (define-type QuadAttrKey Symbol) (define-predicate QuadAttrKey? QuadAttrKey) (define-type QuadAttrValue Any) (define-predicate QuadAttrValue? QuadAttrValue) (define-type QuadAttrs (HashTable QuadAttrKey QuadAttrValue)) (define-type HashableList (Rec duo (U Null (List* QuadAttrKey Any duo)))) (provide HashableList?) (define-predicate HashableList? HashableList) (: quad-attrs? (Any . -> . Boolean)) (define (quad-attrs? x) (and (hash? x) (andmap QuadAttrKey? (hash-keys x)))) (define-type QuadListItem (U Quad String)) (define-type QuadList (Listof QuadListItem)) (define-type (Treeof A) (Rec as (U A (Listof as)))) (struct quad ([name : QuadName] [attrs : QuadAttrs] [list : QuadList]) #:transparent) (define-type Quad quad) (define-predicate Quad? Quad) (define quad-attr-ref (case-lambda [([q : Quad] [key : QuadAttrKey]) (hash-ref (quad-attrs q) key)] [([q : Quad] [key : QuadAttrKey] [default : QuadAttrValue]) (hash-ref (quad-attrs q) key (λ() default))])) (define-syntax (quad-attr-ref/parameter stx) (syntax-case stx () [(_ q key) (with-syntax ([world:key-default (format-id stx "~a-default" (string-trim (symbol->string (syntax->datum #'key)) "-key"))]) #'(quad-attr-ref q key (world:key-default)))])) (define cannot-be-common-attrs '(width x y page)) (define attr-missing (gensym)) (define-type QuadAttrPair (Pairof QuadAttrKey QuadAttrValue)) (: quad-ends-with? (Quad String . -> . Boolean)) (define (quad-ends-with? q str) (cond [(not (empty? (quad-list q))) (define last-item (last (quad-list q))) (cond [(string? last-item) (ends-with? last-item str)] [(quad? last-item) (quad-ends-with? last-item str)] [else #f])] [else #f])) (: quad-append (Quad QuadListItem . -> . Quad)) (define (quad-append q new-item) (quad (quad-name q) (quad-attrs q) (append (quad-list q) (list new-item)))) (: quad->string (Quad . -> . String)) (define (quad->string x) (let loop : String ([x : (U Quad String) x]) (cond [(string? x) x] ;; else branch relies on fact that x is either Quad or String [else (string-append* ((inst map String QuadListItem) loop (quad-list x)))]))) (define/typed+provide (gather-common-attrs qs) ((Listof Quad) . -> . (Option HashableList)) (: check-cap (Quad QuadAttrPair . -> . Boolean)) (define (check-cap q cap) ; cap = candidate-attr-pair (equal? (quad-attr-ref q (car cap) attr-missing) (cdr cap))) (and (not (null? qs)) (let loop ([qs qs] ;; start with the set of pairs in the first quad, then filter it down [candidate-attr-pairs : (Listof QuadAttrPair) (let ([first-attrs (quad-attrs (car qs))]) (if first-attrs (for/fold ([kvps null]) ([k (in-list (hash-keys first-attrs))]) (if (member k cannot-be-common-attrs) kvps (cons (cons k (hash-ref first-attrs k)) kvps))) null))]) (cond [(null? candidate-attr-pairs) #f] ; ran out of possible pairs, so return #f [(null? qs) (cast (flatten candidate-attr-pairs) HashableList)] ; ran out of quads, so return common-attr-pairs ;; todo: reconsider type interface between output of this function and input to quadattrs [else (loop (cdr qs) (filter (λ([cap : QuadAttrPair]) (check-cap (car qs) cap)) candidate-attr-pairs))])))) (: quadattrs ((Listof Any) . -> . QuadAttrs)) (define (quadattrs xs) (let-values ([(ks vs even?) (for/fold ([ks : (Listof Any) null][vs : (Listof Any) null][even? : Boolean #t]) ([x (in-list xs)]) (if even? (values (cons x ks) vs #f) (values ks (cons x vs) #t)))]) (when (not even?) (error 'quadattrs "odd number of elements in ~a" xs)) (cast (for/hash ([k (in-list ks)][v (in-list vs)]) (values k v)) QuadAttrs))) (define-syntax (define-quad-type stx) (syntax-case stx () [(_ id) (with-syntax ([id? (format-id #'id "~a?" #'id)] [quads->id (format-id #'id "quads->~a" #'id)]) #'(begin ;; quad converter (: quads->id ((Listof Quad) . -> . Quad)) (define (quads->id qs) (apply id (gather-common-attrs qs) qs)) (: id (case-> (-> Quad) ((U QuadAttrs (Listof Any) False) (U String Quad) * . -> . Quad))) (define (id [attrs #f] . xs) (quad 'id (cond [(quad-attrs? attrs) (cast attrs QuadAttrs)] [(list? attrs) (if (HashableList? attrs) (quadattrs attrs) (error 'id "got non-hashable list ~a" attrs))] [else (quadattrs '())]) (cast xs QuadList))) (: id? (Any . -> . Boolean)) (define (id? x) (and (quad? x) (equal? (quad-name x) 'id))) ))])) (: whitespace? ((Any) (Boolean) . ->* . Boolean)) (define (whitespace? x [nbsp? #f]) ;((any/c)(boolean?) . ->* . coerce/boolean?) (cond [(quad? x) (whitespace? (quad-list x) nbsp?)] [(string? x) (or (and (regexp-match #px"\\p{Zs}" x) ; Zs = unicode whitespace category (or nbsp? (not (regexp-match #px"\u00a0" x)))))] ; 00a0: nbsp [(list? x) (and (not (empty? x)) (andmap (λ(x) (whitespace? x nbsp?)) x))] ; andmap returns #t for empty lists [else #f])) (define (whitespace/nbsp? x) (whitespace? x #t)) (define-syntax (define-break-type stx) (syntax-case stx () [(_ id) (with-syntax ([split-on-id-breaks (format-id #'id "split-on-~a-breaks" #'id)] [id-break (format-id #'id "~a-break" #'id)] [id-break? (format-id #'id "~a-break?" #'id)] [multi-id (format-id #'id "multi~a" #'id)] [multi-id? (format-id #'id "multi~a?" #'id)] [quads->multi-id (format-id #'id "quads->multi~a" #'id)]) #'(begin (define-quad-type id) (define-quad-type id-break) (define-quad-type multi-id) ;; breaker (: split-on-id-breaks ((Listof Quad) . -> . (Listof (Listof Quad)))) (define (split-on-id-breaks xs) ;; omit leading & trailing whitespace, because they're superfluous next to a break (map (λ([xs : (Listof Quad)]) (trimf xs whitespace?)) (filter-split xs id-break?)))))])) (define quad= equal?) (define-syntax (define-quad-list-function stx) (syntax-case stx () [(_ proc) (with-syntax ([quad-proc (format-id stx "quad-~a" #'proc)]) #'(define/typed (quad-proc q) (Quad . -> . Any) (proc (quad-list q))))])) #;(define-quad-list-function first) (define-quad-list-function car) (define-quad-list-function cdr) #;(define-quad-list-function last) (: quad-has-attr? (Quad QuadAttrKey . -> . Boolean)) (define (quad-has-attr? q key) (hash-has-key? (quad-attrs q) key)) (define-quad-type spacer) (define-quad-type kern) (define-quad-type optical-kern) (define-quad-type flag) (define-quad-type doc) (define-quad-type input) (define-quad-type piece) (define-quad-type run) (define-quad-type box) (define-break-type word) (: word-string (Quad . -> . String)) (define (word-string c) (cast ((inst car QuadListItem Any) (quad-list c)) String)) (define-break-type page) (define-break-type column) (define-break-type block) (define-break-type line)