#lang at-exp racket/base
(require "core.rkt"
         "latex-properties.rkt"
         "private/render-utils.rkt"
         racket/class
         racket/runtime-path
         racket/port
         racket/string
         racket/path
         racket/list
         setup/collects
         file/convertible)
(provide render-mixin
         make-render-part-mixin
         extra-character-conversions)

(define current-table-mode (make-parameter #f))
(define rendering-tt (make-parameter #f))
(define show-link-page-numbers (make-parameter #f))
(define done-link-page-numbers (make-parameter #f))
(define disable-images (make-parameter #f))
(define escape-brackets (make-parameter #f))
(define suppress-newline-content (make-parameter #f))

(define-struct (toc-paragraph paragraph) ())

(define-runtime-path scribble-prefix-tex "scribble-prefix.tex")
(define-runtime-path scribble-packages-tex "scribble-packages.tex")
(define-runtime-path scribble-load-tex "scribble-load.tex")
(define-runtime-path scribble-tex "scribble.tex")
(define-runtime-path scribble-style-tex "scribble-style.tex")
(define-runtime-path scribble-load-replace-tex "scribble-load-replace.tex")

(define (color->string c)
  (if (string? c)
      c
      (format "~a,~a,~a"
              (/ (car c) 255.0)
              (/ (cadr c) 255.0)
              (/ (caddr c) 255.0))))

(define (make-render-part-mixin n)
  (lambda (%)
    (class (render-mixin %)
      (define/override (render-part-depth) n)
      (super-new))))

(define-runtime-path skull-tex "scribble-skull.tex")
(define skull-style (make-style #f (list (tex-addition skull-tex))))

(define extra-character-conversions (make-parameter (λ (c) #f)))

(define (render-mixin % #:image-mode [image-mode #f])
  (class %
    (super-new)

    (inherit-field prefix-file style-file style-extra-files image-preferences)

    (define/override (current-render-mode)
      '(latex))

    (inherit sort-image-requests)
    (define image-reqs 
      (sort-image-requests (cond
                            [(eq? image-mode 'pdf)
                             '(pdf-bytes png@2x-bytes png-bytes)]
                            [(eq? image-mode 'ps)
                             '(eps-bytes)]
                            [else
                             '(pdf-bytes png@2x-bytes png-bytes eps-bytes)])
                           image-preferences))

    (define/override (get-suffix) #".tex")

    (inherit render-block
             render-part
             install-file
             format-number
             number-depth
             extract-part-style-files
             extract-version
             extract-date
             extract-authors
             extract-pretitle)

    (define/override (auto-extra-files? v) (latex-defaults? v))
    (define/override (auto-extra-files-paths v) (latex-defaults-extra-files v))

    (define/public (render-part-depth) #f)

    (define/override (render-one d ri fn)
      (define (maybe-replace file defaults)
        (cond [(and defaults
                    (latex-defaults+replacements? defaults)
                    (hash-ref (latex-defaults+replacements-replacements defaults)
                              (path->string (file-name-from-path file))
                              #f)) =>
               (lambda (v)
                 (cond
                   [(bytes? v) v]
                   [else (collects-relative->path v)]))]
              [else file]))
      (let* ([defaults (ormap (lambda (v) (and (latex-defaults? v) v))
                              (style-properties (part-style d)))]
             [prefix-file (or prefix-file
                              (and defaults
                                   (let ([v (latex-defaults-prefix defaults)])
                                     (cond
                                      [(bytes? v) v]
                                      [else (collects-relative->path v)])))
                              scribble-prefix-tex)]
             [style-file (or style-file
                             (and defaults
                                  (let ([v (latex-defaults-style defaults)])
                                    (cond
                                     [(bytes? v) v]
                                     [else (collects-relative->path v)])))
                             scribble-style-tex)]
             [all-style-files (list* scribble-load-tex
                                     (maybe-replace scribble-load-replace-tex defaults)
                                     scribble-tex
                                     (append (extract-part-style-files
                                              d
                                              ri
                                              (lambda (p) #f)
                                              tex-addition?
                                              tex-addition-path)
                                             (list style-file)
                                             style-extra-files))]
             [whole-doc? (not (render-part-depth))])
        (if whole-doc?
            (for ([style-file (in-list (cons prefix-file all-style-files))])
              (if (bytes? style-file)
                  (display style-file)
                  (with-input-from-file style-file
                    (lambda ()
                      (copy-port (current-input-port) (current-output-port))))))
            (for ([style-file (in-list all-style-files)])
              (if (bytes? style-file)
                  (display style-file)
                  (install-file style-file))))
        (when whole-doc?
          (printf "\\begin{document}\n\\preDoc\n")
          (when (part-title-content d)
            (let ([vers (extract-version d)]
                  [date (extract-date d)]
                  [pres (extract-pretitle d)]
                  [auths (extract-authors d)])
              (for ([pre (in-list pres)])
                (printf "\n\n")
                (do-render-paragraph pre d ri #t #f))
              (when date (printf "\\date{~a}\n" date))
              (printf "\\titleAnd~aVersionAnd~aAuthors{" 
                      (if (equal? vers "") "Empty" "")
                      (if (null? auths) "Empty" ""))
              (render-content (part-title-content d) d ri)
              (printf "}{~a}{" vers)
              (unless (null? auths)
                (printf "\\SNumberOfAuthors{~a}" (length auths)))
              (for/fold ([first? #t]) ([auth (in-list auths)])
                (unless first? (printf "\\SAuthorSep{}"))
                (do-render-paragraph auth d ri #t #f)
                #f)
              (printf "}\n"))))
        (render-part d ri)
        (when whole-doc?
          (printf "\n\n\\postDoc\n\\end{document}\n"))))

    (define/override (render-part-content d ri)
      (let ([number (collected-info-number (part-collected-info d ri))]
            [completely-hidden?
             (and (part-style? d 'hidden)
                  (equal? "" (content->string (part-title-content d))))])
        (when (and (part-title-content d) 
                   (or (pair? number)
                       (let ([d (render-part-depth)])
                         (and d (positive? d)))))
          (when (eq? (style-name (part-style d)) 'index)
            (printf "\\twocolumn\n\\parskip=0pt\n\\addcontentsline{toc}{section}{Index}\n"))
          (let ([pres (extract-pretitle d)])
            (for ([pre (in-list pres)])
              (printf "\n\n")
              (do-render-paragraph pre d ri #t #f)))
          (define depth (+ (number-depth number) (or (render-part-depth) 0)))
          (define grouper? (part-style? d 'grouper))
          (define (inc-section-number)
            (printf "\\Sinc~a" (case depth
                                 [(0 1) (if grouper? "part" "section")]
                                 [(2) "subsection"]
                                 [(3) "subsubsection"]
                                 [(4) "subsubsubsection"]
                                 [else "subsubsubsubsection"])))
          (cond
           [completely-hidden?
            (printf "\n\n\\notitlesection")
            (unless (part-style? d 'unnumbered)
              (inc-section-number))]
           [else
            (define no-number? (and (pair? number) 
                                    (or (not (car number))
                                        (equal? "" (car number))
                                        ((length number) . > . 3))))
            (define no-toc? (part-style? d 'toc-hidden))
            (define (show-number)
              (when (and (part-style? d 'grouper)
                         (depth . > . 1)
                         (not no-number?))
                (printf "~a\\quad{}" (car (format-number number null)))))
            (printf "\n\n\\~a~a~a"
                    (case depth
                      [(0 1) (if grouper?
                                 "partNewpage\n\n\\Spart"
                                 "sectionNewpage\n\n\\Ssection")]
                      [(2) "Ssubsection"]
                      [(3) "Ssubsubsection"]
                      [(4) "Ssubsubsubsection"]
                      [else "Ssubsubsubsubsection"])
                    (if (and grouper?
                             (depth . > . 1))
                        "grouper"
                        "")
                    (if no-number? 
                        (if no-toc?
                            "star"
                            "starx")
                        ""))
            (unless (and no-number? no-toc?)
              (printf "{")
              (show-number)
              (parameterize ([disable-images #t]
                             [escape-brackets #t])
                (render-content (part-title-content d) d ri))
              (printf "}"))
            (printf "{")
            (show-number)
            (render-content (part-title-content d) d ri)
            (printf "}")
            (when (and (part-style? d 'hidden-number)
                       (not (part-style? d 'unnumbered)))
              (inc-section-number))
            (when (eq? (style-name (part-style d)) 'index) (printf "\n\n"))]))
        (for ([t (part-tags d)])
          (printf "\\label{t:~a}~a" (t-encode (add-current-tag-prefix (tag-key t ri)))
                  (if completely-hidden? "" "\n\n")))
        (render-flow (part-blocks d) d ri #f)
        (for ([sec (part-parts d)]) (render-part sec ri))
        (when (eq? (style-name (part-style d)) 'index) (printf "\\onecolumn\n\n"))
        null))

    (define/override (render-paragraph p part ri)
      (do-render-paragraph p part ri #f #f))

    (define/private (do-render-paragraph p part ri show-pre? as-box-mode)
      (let* ([sn (style-name (paragraph-style p))]
             [style (cond
                     [as-box-mode
                      (or
                       (ormap (lambda (a)
                                (and (box-mode? a)
                                     ((box-mode-selector as-box-mode) a)))
                              (style-properties
                               (paragraph-style p)))
                       "hbox")]
                     [(eq? sn 'author) "SAuthor"]
                     [(eq? sn 'pretitle) #f]
                     [(eq? sn 'wraps) #f]
                     [else sn])])
        (unless (and (not show-pre?)
                     (or (eq? sn 'author)
                         (eq? sn 'pretitle)))
          (let ([use-style? (string? style)])
            (when use-style?
              (printf "\\~a{" style))
            (if (toc-paragraph? p)
                (printf "\\newpage \\tableofcontents \\newpage")
                (if as-box-mode
                    (parameterize ([suppress-newline-content #t])
                      (super render-paragraph p part ri))
                    (super render-paragraph p part ri)))
            (when use-style? (printf "}")))))
      null)

    (define/private (no-noindent? p ri)
      (cond
       [(delayed-block? p)
        (no-noindent? (delayed-block-blocks p ri) ri)]
       [(traverse-block? p)
        (no-noindent? (traverse-block-block p ri) ri)]
       [else
        (or
         (memq 'never-indents 
               (style-properties 
                (cond
                 [(paragraph? p) (paragraph-style p)]
                 [(compound-paragraph? p) (compound-paragraph-style p)]
                 [(nested-flow? p) (nested-flow-style p)]
                 [(table? p) (table-style p)]
                 [(itemization? p) (itemization-style p)]
                 [else plain])))
         (and (nested-flow? p)
              (pair? (nested-flow-blocks p))
              (no-noindent? (car (nested-flow-blocks p)) ri))
         (and (compound-paragraph? p)
              (pair? (compound-paragraph-blocks p))
              (no-noindent? (car (compound-paragraph-blocks p)) ri)))]))

    (define/override (render-intrapara-block p part ri first? last? starting-item?)
      (unless first?
        (printf "\n\n")
        (unless (no-noindent? p ri)
          (printf "\\noindent ")))
      (super render-intrapara-block p part ri first? last? starting-item?))

    (define/override (render-content e part ri)
      (let ([part-label? (and (link-element? e)
                              (pair? (link-element-tag e))
                              (eq? 'part (car (link-element-tag e)))
                              (empty-content? (element-content e)))])
        (parameterize ([done-link-page-numbers (or (done-link-page-numbers)
                                                   (link-element? e))])
          (when (target-element? e)
            (printf "\\label{t:~a}"
                    (t-encode (add-current-tag-prefix (tag-key (target-element-tag e) ri)))))
          (when part-label?
            (define-values (dest ext?) (resolve-get/ext? part ri (link-element-tag e)))
            (let* ([number (and dest (vector-ref dest 2))]
                   [formatted-number (and dest
                                          (list? number)
                                          (format-number number null))]
                   [lbl? (and dest 
                              (not ext?)
                              (not (show-link-page-numbers)))])
              (printf "\\~aRef~a~a~a{"
                      (case (and dest (number-depth number))
                        [(0) "Book"]
                        [(1) (if (string? (car number)) "Part" "Chap")]
                        [else "Sec"])
                      (if lbl?
                          "Local"
                          "")
                      (if (let ([s (element-style e)])
                            (and (style? s) (memq 'uppercase (style-properties s))))
                          "UC"
                          "")
                      (if (null? formatted-number)
                          "UN"
                          ""))
              (when lbl?
                (printf "t:~a}{" (t-encode (vector-ref dest 1))))
              (unless (null? formatted-number)
                (render-content
                 (if dest
                     (if (list? number)
                         formatted-number
                         (begin (eprintf "Internal tag error: ~s -> ~s\n"
                                         (link-element-tag e)
                                         dest)
                                '("!!!")))
                     (list "???"))
                 part ri)
                (printf "}{"))))
          (let* ([es (cond
                      [(element? e) (element-style e)]
                      [(multiarg-element? e) (multiarg-element-style e)]
                      [else #f])]
                 [style-name (if (style? es)
                                 (style-name es)
                                 es)]
                 [style (and (style? es) es)]
                 [check-render
                  (lambda ()
                    (when (render-element? e)
                      ((render-element-render e) this part ri)))]
                 [core-render (lambda (e tt?)
                                (cond
                                 [(and (image-element? e)
                                       (not (disable-images)))
                                  (check-render)
                                  (let ([fn (install-file
                                             (select-suffix 
                                              (collects-relative->path
                                               (image-element-path e))
                                              (image-element-suffixes e) 
                                              '(".pdf" ".ps" ".png")))])
                                    (printf "\\includegraphics[scale=~a]{~a}"
                                            (image-element-scale e) fn))]
                                 [(and (convertible? e)
                                       (not (disable-images))
                                       (let ([ftag (lambda (v suffix [scale 1]) (and v (list v suffix scale)))]
                                             [xxlist (lambda (v) (and v (list v #f #f #f #f #f #f #f #f)))]
                                             [xlist (lambda (v) (and v (append v (list 0 0 0 0))))])
                                         (for/or ([req (in-list image-reqs)])
                                           (case req
                                             [(eps-bytes)
                                              (or (ftag (convert e 'eps-bytes+bounds8) ".ps")
                                                  (ftag (xlist (convert e 'eps-bytes+bounds)) ".ps")
                                                  (ftag (xxlist (convert e 'eps-bytes)) ".ps"))]
                                             [(pdf-bytes)
                                              (or (ftag (convert e 'pdf-bytes+bounds8) ".pdf")
                                                  (ftag (xlist (convert e 'pdf-bytes+bounds)) ".pdf")
                                                  (ftag (xxlist (convert e 'pdf-bytes)) ".pdf"))]
                                             [(png@2x-bytes)
                                              (or (ftag (convert e 'png@2x-bytes+bounds8) ".png" 0.5)
                                                  (ftag (xxlist (convert e 'png@2x-bytes)) ".png" 0.5))]
                                             [(png-bytes)
                                              (or (ftag (convert e 'png-bytes+bounds8) ".png")
                                                  (ftag (xxlist (convert e 'png-bytes)) ".png"))]))))
                                  => (lambda (bstr+info+suffix)
                                       (check-render)
                                       (let* ([bstr (list-ref (list-ref bstr+info+suffix 0) 0)]
                                              [suffix (list-ref bstr+info+suffix 1)]
                                              [scale (list-ref bstr+info+suffix 2)]
                                              [height (list-ref (list-ref bstr+info+suffix 0) 2)]
                                              [pad-left (or (list-ref (list-ref bstr+info+suffix 0) 5) 0)]
                                              [pad-top (or (list-ref (list-ref bstr+info+suffix 0) 6) 0)]
                                              [pad-right (or (list-ref (list-ref bstr+info+suffix 0) 7) 0)]
                                              [pad-bottom (or (list-ref (list-ref bstr+info+suffix 0) 8) 0)]
                                              [descent (and height
                                                            (- (+ (list-ref (list-ref bstr+info+suffix 0) 3)
                                                                  (- (ceiling height) height))
                                                               pad-bottom))]
                                              [width (let ([w (list-ref (list-ref bstr+info+suffix 0) 1)])
                                                       (and w (- w pad-left pad-right)))]
                                              [fn (install-file (format "pict~a" suffix) bstr)])
                                         (if descent
                                             (printf "\\raisebox{-~abp}{\\makebox[~abp][l]{\\includegraphics[~atrim=~a ~a ~a ~a]{~a}}}" 
                                                     descent
                                                     width
                                                     (if (= scale 1) "" (format "scale=~a," scale))
                                                     (/ pad-left scale) (/ pad-bottom scale) (/ pad-right scale) (/ pad-top scale)
                                                     fn)
                                             (printf "\\includegraphics{~a}" fn))))]
                                 [else
                                  (parameterize ([rendering-tt (or tt? (rendering-tt))])
                                    (super render-content e part ri))]))]
                 [wrap (lambda (e s tt?)
                         (when s (printf "\\~a{" s))
                         (core-render e tt?)
                         (when s (printf "}")))])
            (define (finish tt?)
              (cond
               [(symbol? style-name)
                (case style-name
                  [(italic) (wrap e "textit" tt?)]
                  [(bold) (wrap e "textbf" tt?)]
                  [(tt) (wrap e "Scribtexttt" #t)]
                  [(url) (wrap e "Snolinkurl" 'url)]
                  [(no-break) (wrap e "mbox" tt?)]
                  [(sf) (wrap e "textsf" #f)]
                  [(roman) (wrap e "textrm" #f)]
                  [(subscript) (wrap e "textsub" #f)]
                  [(superscript) (wrap e "textsuper" #f)]
                  [(smaller) (wrap e "Smaller" #f)]
                  [(larger) (wrap e "Larger" #f)]
                  [(hspace)
                   (check-render)
                   (let ([s (content->string e)])
                     (case (string-length s)
                       [(0) (void)]
                       [else
                        (printf "\\mbox{\\hphantom{\\Scribtexttt{~a}}}"
                                (regexp-replace* #rx"." s "x"))]))]
                  [(newline) 
                   (check-render)
                   (unless (suppress-newline-content)
                     (printf "\\hspace*{\\fill}\\\\"))]
                  [else (error 'latex-render
                               "unrecognized style symbol: ~s" style)])]
               [(string? style-name)
                (let* ([v (if style (style-properties style) null)]
                       [tt? (cond
                             [(memq 'tt-chars v) #t]
                             [(memq 'exact-chars v) 'exact]
                             [else tt?])])
                  (cond
                   [(multiarg-element? e)
                    (check-render)
                    (printf "\\~a" style-name)
                    (if (null? (multiarg-element-contents e))
                        (printf "{}")
                        (for ([i (in-list (multiarg-element-contents e))])
                          (printf "{")
                          (parameterize ([rendering-tt (or tt? (rendering-tt))])
                            (render-content i part ri))
                          (printf "}")))]
                   [else
                    (wrap e style-name tt?)]))]
               [(and (not style-name)
                     style
                     (memq 'exact-chars (style-properties style)))
                (wrap e style-name 'exact)]
               [else
                (core-render e tt?)]))
            (let loop ([l (if style (style-properties style) null)] [tt? #f])
              (if (null? l)
                  (finish tt?)
                  (let ([v (car l)])
                    (cond
                     [(target-url? v)
                      (define target (let* ([s (let ([p (target-url-addr v)])
                                                 (if (path? p)
                                                     (path->string p)
                                                     p))]
                                            [s (regexp-replace* #rx"\\\\" s "%5c")]
                                            [s (regexp-replace* #rx"{" s "%7b")]
                                            [s (regexp-replace* #rx"}" s "%7d")]
                                            [s (regexp-replace* #rx"%" s "\\\\%")])
                                       s))
                      (if (regexp-match? #rx"^[^#]*#[^#]*$" target)
                          ;; work around a problem with `\href' as an
                          ;; argument to other macros, such as `\marginpar':
                          (let ([l (string-split target "#")])
                            (printf "\\Shref{~a}{~a}{" (car l) (cadr l)))
                          ;; normal:
                          (printf "\\href{~a}{" target))
                      (loop (cdr l) #t)
                      (printf "}")]
                     [(color-property? v)
                      (printf "\\intext~acolor{~a}{"
                              (if (string? (color-property-color v)) "" "rgb")
                              (color->string (color-property-color v)))
                      (loop (cdr l) tt?)
                      (printf "}")]
                     [(background-color-property? v)
                      (printf "\\in~acolorbox{~a}{"
                              (if (string? (background-color-property-color v)) "" "rgb")
                              (color->string (background-color-property-color v)))
                      (loop (cdr l) tt?)
                      (printf "}")]
                     [(command-extras? (car l))
                      (loop (cdr l) tt?)
                      (for ([l (in-list (command-extras-arguments (car l)))])
                        (printf "{~a}" l))]
                     [else (loop (cdr l) tt?)]))))))
        (when part-label?
          (printf "}"))
        (when (and (link-element? e)
                   (show-link-page-numbers)
                   (not (done-link-page-numbers)))
          (printf ", \\pageref{t:~a}"
                  (t-encode 
                   (let ([v (resolve-get part ri (link-element-tag e))])
                     (and v (vector-ref v 1))))))
        null))

    (define/private (t-encode s)
      (string-append*
       (map (lambda (c)
              (cond
                [(and (or (char-alphabetic? c) (char-numeric? c))
                      ((char->integer c) . < . 128))
                 (string c)]
                [(char=? c #\space) "_"]
                [else (format "x~x" (char->integer c))]))
            (string->list (format "~s" s)))))

    (define/override (render-flow p part ri starting-item? [wrap-each? #f])
      (if (null? p)
          null
          (begin
            (when wrap-each? (printf "{"))
            (render-block (car p) part ri starting-item?)
            (when wrap-each? (printf "}"))
            (for ([b (in-list (cdr p))])
              (if wrap-each?
                  (printf "%\n{")
                  (printf "\n\n"))
              (render-block b part ri #f)
              (when wrap-each? (printf "}")))
            null)))

    (define/override (render-table t part ri starting-item?)
      (render-table* t part ri starting-item? "[t]"))

    (define/private (render-table* t part ri starting-item? alignment)
      (let* ([s-name (style-name (table-style t))]
             [boxed? (eq? 'boxed s-name)]
             [index? (eq? 'index s-name)]
             [tableform
              (cond [index? "list"]
                    [(eq? 'block s-name) "tabular"]
                    [(not (current-table-mode)) "bigtabular"]
                    [else "tabular"])]
             [opt (cond [(equal? tableform "bigtabular") ""]
                        [(equal? tableform "tabular") alignment]
                        [else ""])]
             [blockss (if index? (cddr (table-blockss t)) (table-blockss t))]
             [cell-styless (extract-table-cell-styles t)]
             [twidth (if (null? (table-blockss t))
                         1
                         (length (car (table-blockss t))))]
             [single-column? (and (= 1 twidth)
                                  (or (not s-name) (string? s-name))
                                  (not (ormap (lambda (cell-styles)
                                                (ormap (lambda (s) 
                                                         (or (string? (style-name s))
                                                             (let ([l (style-properties s)])
                                                               (or (memq 'right l)
                                                                   (memq 'center l)))))
                                                       cell-styles))
                                              cell-styless))
                                  (not (current-table-mode)))]
             [inline?
              (and (not single-column?)
                   (not boxed?) 
                   (not index?)
                   (ormap (lambda (rs) 
                            (ormap (lambda (cs) (style-name cs)) rs))
                          cell-styless)
                   (= 1 twidth)
                   (let ([m (current-table-mode)])
                     (and m
                          (equal? "bigtabular" (car m))
                          (= 1 (length (car (table-blockss (cadr m))))))))])
        (if single-column?
            (begin
              (when (string? s-name)
                (printf "\\begin{~a}" s-name))
              (do-render-nested-flow 
               (make-nested-flow (make-style "SingleColumn" null) (map car (table-blockss t)))
               part 
               ri
               #t
               #f)
              (when (string? s-name)
                (printf "\\end{~a}" s-name)))
            (unless (or (null? blockss) (null? (car blockss)))
              (define all-left-line?s
                (if (null? cell-styless)
                    null
                    (for/list ([i (in-range (length (car cell-styless)))])
                      (for/and ([cell-styles (in-list cell-styless)])
                        (let ([cell-style (list-ref cell-styles i)])
                          (or (memq 'left-border (style-properties cell-style))
                              (memq 'border (style-properties cell-style))))))))
              (define all-right-line?
                (and (pair? cell-styless)
                     (let ([i (sub1 (length (car cell-styless)))])
                       (for/and ([cell-styles (in-list cell-styless)])
                         (let ([cell-style (list-ref cell-styles i)])
                           (or (memq 'right-border (style-properties cell-style))
                               (memq 'border (style-properties cell-style))))))))
              (parameterize ([current-table-mode
                              (if inline? (current-table-mode) (list tableform t))]
                             [show-link-page-numbers
                              (or index? (show-link-page-numbers))])
                (cond
                 [index? (printf "\\begin{list}{}{\\parsep=0pt \\itemsep=1pt \\leftmargin=2ex \\itemindent=-2ex}\n")]
                 [inline? (void)]
                 [single-column? (printf "\\begin{tabbing}\n")]
                 [else
                  (printf "~a~a\\begin{~a}~a{@{~a}~a}\n~a"
                          (if (and starting-item? (equal? tableform "bigtabular"))
                              "\\bigtableinlinecorrect"
                              "")
                          (if (string? s-name)
                              (format "\\begin{~a}" s-name)
                              "")
                          tableform
                          opt
                          (if (equal? tableform "bigtabular")
                              "\\bigtableleftpad"
                              "")
                          (string-append*
                           (let ([l
                                  (map (lambda (i cell-style left-line?)
                                         (format "~a~a@{}"
                                                 (if left-line? "|@{}" "")
                                                 (cond
                                                  [(memq 'center (style-properties cell-style)) "c"]
                                                  [(memq 'right (style-properties cell-style)) "r"]
                                                  [else "l"])))
                                       (car blockss)
                                       (car cell-styless)
                                       all-left-line?s)])
                             (let ([l (if all-right-line? (append l '("|")) l)])
                               (if boxed? (cons "@{\\SBoxedLeft}" l) l))))
                          "")])
                ;; Helper to add row-separating lines:
                (define (add-clines prev-styles next-styles)
                  (let loop ([pos 1] [start #f] [prev-styles prev-styles] [next-styles next-styles])
                    (cond
                     [(or (and prev-styles (null? prev-styles))
                          (and next-styles (null? next-styles)))
                      (when start
                        (if (= start 1)
                            (printf "\\hline ")
                            (printf "\\cline{~a-~a}" start (sub1 pos))))]
                     [else
                      (define prev-style (and prev-styles (car prev-styles)))
                      (define next-style (and next-styles (car next-styles)))
                      (define line? (or (and prev-style
                                             (or (memq 'bottom-border (style-properties prev-style))
                                                 (memq 'border (style-properties prev-style))))
                                        (and next-style
                                             (or (memq 'top-border (style-properties next-style))
                                                 (memq 'border (style-properties next-style))))))
                      (when (and start (not line?))
                        (printf "\\cline{~a-~a}" start (sub1 pos)))
                      (loop (add1 pos) (and line? (or start pos))
                            (and prev-styles (cdr prev-styles))
                            (and next-styles (cdr next-styles)))])))
                ;; Loop through rows:
                (let loop ([blockss blockss]
                           [cell-styless cell-styless]
                           [prev-styles #f]) ; for 'bottom-border styles
                  (let ([flows (car blockss)]
                        [cell-styles (car cell-styless)])
                    (unless index? (add-clines prev-styles cell-styles))
                    (let loop ([flows flows]
                               [cell-styles cell-styles]
                               [all-left-line?s all-left-line?s]
                               [need-left? #f])
                      (unless (null? flows)
                        (define (render-cell cnt)
                          (render-table-cell (car flows) part ri (/ twidth cnt) (car cell-styles) (not index?)))
                        (define right-line?
                          (cond
                           [index?
                            (printf "\n\\item ")
                            (render-cell 1)
                            #f]
                           [(eq? 'cont (car flows))
                            #f]
                           [else
                            (let ([cnt (let loop ([flows (cdr flows)][n 1])
                                         (cond [(null? flows) n]
                                               [(eq? (car flows) 'cont)
                                                (loop (cdr flows) (add1 n))]
                                               [else n]))])
                              (unless (= cnt 1) (printf "\\multicolumn{~a}{l}{" cnt))
                              (when (and (not (car all-left-line?s))
                                         (or need-left?
                                             (memq 'left-border (style-properties (car cell-styles)))
                                             (memq 'border (style-properties (car cell-styles)))))
                                (printf "\\vline "))
                              (render-cell cnt)
                              (define right-line? (or (memq 'right-border (style-properties (list-ref cell-styles (sub1 cnt))))
                                                      (memq 'border (style-properties (list-ref cell-styles (sub1 cnt))))))
                              (when (and right-line? (null? (list-tail flows cnt)) (not all-right-line?))
                                (printf "\\vline "))
                              (unless (= cnt 1) (printf "}"))
                              (unless (null? (list-tail flows cnt))
                                (printf " &\n"))
                              right-line?)]))
                        (unless (null? (cdr flows)) (loop (cdr flows)
                                                          (cdr cell-styles)
                                                          (cdr all-left-line?s)
                                                          right-line?))))
                    (unless (or index?
                                (and (null? (cdr blockss))
                                     (not (for/or ([cell-style (in-list cell-styles)])
                                            (or (memq 'bottom-border (style-properties cell-style))
                                                (memq 'border (style-properties cell-style)))))))
                      (printf " \\\\\n"))
                    (cond
                     [(null? (cdr blockss))
                      (unless index? (add-clines cell-styles #f))]
                     [else
                      (loop (cdr blockss) (cdr cell-styless) cell-styles)])))
                (unless inline?
                  (printf "\\end{~a}~a"
                          tableform
                          (if (string? s-name)
                              (format "\\end{~a}" s-name)
                              "")))))))
      null)

    (define/private (render-table-cell p part ri twidth vstyle can-box?)
      (let* ([top? (or (memq 'top (style-properties vstyle))
                       (memq 'baseline (style-properties vstyle)))]
             [bottom? (and (not top?)
                           (memq 'bottom (style-properties vstyle)))]
             [center? (and (not bottom?)
                           (not top?))]
             [as-box? (and can-box? (boxable? p))])
        (when (string? (style-name vstyle))
          (printf "\\~a{" (style-name vstyle)))
        (let ([minipage? (and can-box? (not as-box?))])
          (when minipage?
            (printf "\\begin{minipage}~a{~a\\linewidth}\n"
                    (cond
                     [top? "[t]"]
                     [center? "[c]"]
                     [else ""])
                    (/ 1.0 twidth)))
          (cond
           [(table? p)
            (render-table* p part ri #f (cond
                                         [top? "[t]"]
                                         [center? "[c]"]
                                         [else "[b]"]))]
           [as-box?
            (render-boxable-block p part ri (cond
                                             [top? 't]
                                             [center? 'c]
                                             [else 'b]))]
           [else
            (render-block p part ri #f)])
          (when minipage?
            (printf " \\end{minipage}\n")))
        (when (string? (style-name vstyle))
          (printf "}"))
        null))

    (define/private (boxable? p)
      (or (and (table? p)
               (for* ([l (in-list (table-blockss p))]
                      [p (in-list l)])
                 (boxable? p)))
          (and (nested-flow? p)
               (or (and (= 1 (length (nested-flow-blocks p)))
                        (memq (style-name (nested-flow-style p))
                              '(code-inset vertical-inset)))
                   (and
                    (ormap box-mode? (style-properties (nested-flow-style p)))
                    (andmap (lambda (p) (boxable? p)) (nested-flow-blocks p)))))
          (and (paragraph? p)
               (or (not (style-name (paragraph-style p)))
                   (ormap box-mode? (style-properties (paragraph-style p)))))))

    (define/private (render-boxable-block p part ri mode)
      (cond
       [(table? p)
        (render-table* p part ri #f (format "[~a]" mode))]
       [(nested-flow? p)
        (do-render-nested-flow p part ri #f mode)]
       [(paragraph? p)
        (do-render-paragraph p part ri #f mode)]))

    (define/private (box-mode-selector as-box-mode)
      (case as-box-mode
        [(t) box-mode-top-name]
        [(c) box-mode-center-name]
        [(b) box-mode-bottom-name]))

    (define/override (render-itemization t part ri)
      (let* ([style-str (let ([s (style-name (itemization-style t))])
                          (if (eq? s 'compact)
                              "compact"
                              s))]
             [mode (or (and (string? style-str)
                            style-str)
                       (if (eq? 'ordered style-str)
                           "enumerate"
                           "itemize"))])
        (printf "\\begin{~a}\\atItemizeStart" mode)
        (for ([flow (in-list (itemization-blockss t))])
          (printf "\n\n\\~a" (if (string? style-str)
                                  (format "~aItem{" style-str)
                                  "item "))
          (render-flow flow part ri #t)
          (when (string? style-str)
            (printf "}")))
        (printf "\\end{~a}" mode)
        null))

    (define/private (do-render-nested-flow t part ri single-column? as-box-mode)
      (let* ([props (style-properties (nested-flow-style t))]
             [kind (or (and as-box-mode
                            (or
                             (ormap (lambda (a)
                                      (and (box-mode? a)
                                           ((box-mode-selector as-box-mode) a)))
                                    props)
                             (case (style-name (nested-flow-style t))
                               [(code-inset) "SCodeInsetBox"]
                               [(vertical-inset) "SVInsetBox"]
                               [else (error "unexpected style for box mode")])))
                       (let ([s (style-name (nested-flow-style t))])
                         (or (and (string? s) s)
                             (and (eq? s 'inset) "SInsetFlow")
                             (and (eq? s 'code-inset) "SCodeFlow")
                             (and (eq? s 'vertical-inset) "SVInsetFlow")))
                       "Subflow")]
             [multicommand? (memq 'multicommand props)]
             [command? (or (and as-box-mode (not multicommand?))
                           (memq 'command props))])
        (cond
         [command? (printf "\\~a{" kind)]
         [multicommand? (printf "\\~a" kind)]
         [else (printf "\\begin{~a}" kind)])
        (parameterize ([current-table-mode (if (or single-column?
                                                   (not (current-table-mode)))
                                               (current-table-mode)
                                               (list "nested-flow" t))])
          (if as-box-mode
              (for-each (lambda (p) 
                          (when multicommand? (printf "{"))
                          (render-boxable-block p part ri as-box-mode)
                          (when multicommand? (printf "}")))
                        (nested-flow-blocks t))
              (render-flow (nested-flow-blocks t) part ri #f multicommand?)))
        (cond
         [command? (printf "}")]
         [multicommand? (void)]
         [else (printf "\\end{~a}" kind)])
        null))

    (define/override (render-nested-flow t part ri starting-item?)
      (do-render-nested-flow t part ri #f #f))

    (define/override (render-compound-paragraph t part ri starting-item?)
      (let ([kind (style-name (compound-paragraph-style t))]
            [command? (memq 'command (style-properties (compound-paragraph-style t)))])
        (when kind
          (if command?
              (printf "\\~a{" kind)
              (printf "\\begin{~a}" kind)))
        (super render-compound-paragraph t part ri starting-item?)
        (when kind
          (if command?
              (printf "}")
              (printf "\\end{~a}" kind)))
        null))

    (define/override (render-other i part ri)
      (cond
        [(string? i) (display-protected i)]
        [(symbol? i)
         (display (case i
                    [(nbsp) "~"]
                    [(mdash) "{---}"]
                    [(ndash) "{--}"]
                    [(ldquo) "{``}"]
                    [(rdquo) "{''}"]
                    [(rsquo) "{'}"]
                    [(lsquo) "{`}"]
                    [(prime) "$'$"]
                    [(rarr) "$\\rightarrow$"]
                    [(larr) "$\\leftarrow$"]
                    [(alpha) "$\\alpha$"]
                    [(infin) "$\\infty$"]
                    [(lang) "$\\langle$"]
                    [(rang) "$\\rangle$"]
                    [else (error 'render "unknown symbol element: ~e" i)]))]
        [else (display-protected (format "~s" i))])
      null)

    (define/override (string-to-implicit-styles e)
      (for/fold ([ses null]) ([ch (in-string e)])
        (case ch
          [(#\☠) (cons skull-style ses)]
          [else ses])))

    (define/private (display-protected s)
      (define rtt   (rendering-tt))
      (define convs (extra-character-conversions))
      (cond
       [(eq? rtt 'exact)
        (display s)]
       [(eq? rtt 'url)
        (for ([c (in-string s)])
          (case c
            [(#\%) (display "\\%")]
            [(#\#) (display "\\#")]
            [(#\\) (display "\\%5c")]
            [(#\{) (display "\\%7b")]
            [(#\}) (display "\\%7d")]
            [else (display c)]))]
       [else
        ;; Start by normalizing to "combined" form, so that Racket characters
        ;; are closer to Unicode characters (e.g., ä is one character, instead
        ;; of a combining character followed by "a").
        (let ([s (string-normalize-nfc s)])
          (let ([len (string-length s)])
            (let loop ([i 0])
              (unless (= i len)
                (display
                 (let char-loop ([c (string-ref s i)])
                   (case c
                     [(#\\) (if (rendering-tt)
                                "{\\char`\\\\}"
                                "$\\backslash$")]
                     [(#\_) (if (rendering-tt)
                                "{\\char`\\_}"
                                "$\\_$")]
                     [(#\^) "{\\char'136}"]
                     [(#\>) (if (rendering-tt) "{\\Stttextmore}" "$>$")]
                     [(#\<) (if (rendering-tt) "{\\Stttextless}" "$<$")]
                     [(#\|) (if (rendering-tt) "{\\Stttextbar}" "$|$")]
                     [(#\-) "{-}"] ;; avoid en- or em-dash
                     [(#\`) "{\\textasciigrave}"]
                     [(#\') "{\\textquotesingle}"]
                     [(#\? #\! #\. #\:)
                      (if (rendering-tt) (format "{\\hbox{\\texttt{~a}}}" c) c)]
                     [(#\~) "$\\sim$"]
                     [(#\{ #\}) (if (rendering-tt)
                                    (format "{\\char`\\~a}" c)
                                    (format "\\~a" c))]
                     [(#\[ #\]) (if (escape-brackets)
                                    (if (eq? c #\[)
                                        "{\\SOpenSq}"
                                        "{\\SCloseSq}")
                                    c)]
                     [(#\# #\% #\& #\$) (format "\\~a" c)]
                     [(#\uA0) "~"] ; non-breaking space
                     [(#\uAD) "\\-"] ; soft hyphen; unfortunately, also disables auto-hyphen
                     [(#\uDF) "{\\ss}"]
                     [else
                      (if ((char->integer c) . > . 127)
                          ;; first, try user-defined conversions
                          (or (convs c)
                              ;; latex-prefix.rkt enables utf8 input, but this does not work for
                              ;; all the characters below (e.g. ∞). Some parts of the table
                              ;; below are therefore necessary, but some parts probably are not.
                              ;; Which parts are necessary may depend on the latex version,
                              ;; though, so we keep this table around to avoid regressions.
                              (case c
                                [(#\╔ #\═ #\╗ #\║ #\╚ #\╝ #\╦ #\╠ #\╣ #\╬ #\╩) (box-character c)]
                                [(#\┌ #\─ #\┐ #\│ #\└ #\┘ #\┬ #\├ #\┤ #\┼ #\┴) (box-character c)]
                                [(#\┏ #\━ #\┓ #\┃ #\┗ #\┛ #\┳ #\┣ #\┫ #\╋ #\┻) (box-character c 2)]
                                [(#\u2011) "\\mbox{-}"] ; non-breaking hyphen
                                [(#\uB0) "$^{\\circ}$"] ; degree
                                [(#\uB2) "$^2$"]
                                [(#\u039A) "K"] ; kappa
                                [(#\u0391) "A"] ; alpha
                                [(#\u039F) "O"] ; omicron
                                [(#\u03A3) "$\\Sigma$"]
                                [(#\u03BA) "$\\kappa$"]
                                [(#\u03B1) "$\\alpha$"]
                                [(#\u03B2) "$\\beta$"]
                                [(#\u03B3) "$\\gamma$"]
                                [(#\u03BF) "o"] ; omicron
                                [(#\u03C3) "$\\sigma$"]
                                [(#\u03C2) "$\\varsigma$"]
                                [(#\u03BB) "$\\lambda$"]
                                [(#\u039B) "$\\Lambda$"]
                                [(#\u03BC) "$\\mu$"]
                                [(#\u03C0) "$\\pi$"]
                                [(#\‘) "{`}"]
                                [(#\’) "{'}"]
                                [(#\“) "{``}"]
                                [(#\”) "{''}"]
                                [(#\u2013) "{--}"]
                                [(#\u2014) "{---}"]
                                [(#\⟨ #\〈) "$\\langle$"] ; [MATHEMATICAL] LEFT ANGLE BRACKET
                                [(#\⟩ #\〉) "$\\rangle$"] ; [MATHEMATICAL] RIGHT ANGLE BRACKET
                                [(#\∞) "$\\infty$"]
                                [(#\⇓) "$\\Downarrow$"]
                                [(#\↖) "$\\nwarrow$"]
                                [(#\↓) "$\\downarrow$"]
                                [(#\⇒) "$\\Rightarrow$"]
                                [(#\→) "$\\rightarrow$"]
                                [(#\↘) "$\\searrow$"]
                                [(#\↙) "$\\swarrow$"]
                                [(#\←) "$\\leftarrow$"]
                                [(#\↑) "$\\uparrow$"]
                                [(#\⇐) "$\\Leftarrow$"]
                                [(#\−) "$\\longrightarrow$"]
                                [(#\⇑) "$\\Uparrow$"]
                                [(#\⇔) "$\\Leftrightarrow$"]
                                [(#\↕) "$\\updownarrow$"]
                                [(#\↔) "$\\leftrightarrow$"]
                                [(#\↗) "$\\nearrow$"]
                                [(#\⇕) "$\\Updownarrow$"]
                                [(#\א) "$\\aleph$"]
                                [(#\′) "$\\prime$"]
                                [(#\∅) "$\\emptyset$"]
                                [(#\∇) "$\\nabla$"]
                                [(#\♦) "$\\diamondsuit$"]
                                [(#\♠) "$\\spadesuit$"]
                                [(#\♣) "$\\clubsuit$"]
                                [(#\♥) "$\\heartsuit$"]
                                [(#\♯) "$\\sharp$"]
                                [(#\♭) "$\\flat$"]
                                [(#\♮) "$\\natural$"]
                                [(#\√) "$\\surd$"]
                                [(#\∆) "$\\Delta$"] ; no better mapping for than \Delta for "increment"
                                [(#\u2211) "$\\sum$"] ; better than \Sigma, right?
                                [(#\u220F) "$\\prod$"] ; better than \Pi, right?
                                [(#\u2210) "$\\coprod$"]
                                [(#\u222B) "$\\int$"]
                                [(#\u222E) "$\\oint$"]
                                [(#\¬) "$\\neg$"]
                                [(#\△) "$\\triangle$"]
                                [(#\∀) "$\\forall$"]
                                [(#\∃) "$\\exists$"]
                                [(#\∘) "$\\circ$"]
                                [(#\θ) "$\\theta$"]
                                [(#\ϑ) "$\\vartheta$"]
                                [(#\τ) "$\\tau$"]
                                [(#\υ) "$\\upsilon$"]
                                [(#\φ) "$\\phi$"]
                                [(#\ϕ) "$\\varphi$"]
                                [(#\δ) "$\\delta$"]
                                [(#\ρ) "$\\rho$"]
                                [(#\ϱ) "$\\varrho$"]
                                [(#\ϵ) "$\\epsilon$"]
                                [(#\ε) "$\\varepsilon$"]
                                [(#\ϖ) "$\\varpi$"]
                                [(#\χ) "$\\chi$"]
                                [(#\ψ) "$\\psi$"]
                                [(#\ζ) "$\\zeta$"]
                                [(#\ν) "$\\nu$"]
                                [(#\ω) "$\\omega$"]
                                [(#\η) "$\\eta$"]
                                [(#\ι) "$\\iota$"]
                                [(#\ξ) "$\\xi$"]
                                [(#\Γ) "$\\Gamma$"]
                                [(#\Ψ) "$\\Psi$"]
                                [(#\Δ) "$\\Delta$"]
                                [(#\Ξ) "$\\Xi$"]
                                [(#\Υ) "$\\Upsilon$"]
                                [(#\Ω) "$\\Omega$"]
                                [(#\Θ) "$\\Theta$"]
                                [(#\Π) "$\\Pi$"]
                                [(#\Φ) "$\\Phi$"]
                                [(#\±) "$\\pm$"]
                                [(#\∩) "$\\cap$"]
                                [(#\◇) "$\\diamond$"]
                                [(#\⊕) "$\\oplus$"]
                                [(#\∓) "$\\mp$"]
                                [(#\∪) "$\\cup$"]
                                [(#\△) "$\\bigtriangleup$"]
                                [(#\⊖) "$\\ominus$"]
                                [(#\×) "$\\times$"]
                                [(#\⊎) "$\\uplus$"]
                                [(#\▽) "$\\bigtriangledown$"]
                                [(#\⊗) "$\\otimes$"]
                                [(#\÷) "$\\div$"]
                                [(#\⊓) "$\\sqcap$"]
                                [(#\▹) "$\\triangleleft$"]
                                [(#\⊘) "$\\oslash$"]
                                [(#\∗) "$\\ast$"]
                                [(#\⊔) "$\\sqcup$"]
                                [(#\∨) "$\\vee$"]
                                [(#\∧) "$\\wedge$"]
                                [(#\◃) "$\\triangleright$"]
                                [(#\⊙) "$\\odot$"]
                                [(#\★) "$\\star$"]
                                [(#\†) "$\\dagger$"]
                                [(#\•) "$\\bullet$"]
                                [(#\‡) "$\\ddagger$"]
                                [(#\≀) "$\\wr$"]
                                [(#\⨿) "$\\amalg$"]
                                [(#\≤) "$\\leq$"]
                                [(#\≥) "$\\geq$"]
                                [(#\≡) "$\\equiv$"]
                                [(#\⊨) "$\\models$"]
                                [(#\≺) "$\\prec$"]
                                [(#\≻) "$\\succ$"]
                                [(#\∼) "$\\sim$"]
                                [(#\⊥) "$\\perp$"]
                                [(#\≼) "$\\preceq$"]
                                [(#\≽) "$\\succeq$"]
                                [(#\≃) "$\\simeq$"]
                                [(#\≪) "$\\ll$"]
                                [(#\≫) "$\\gg$"]
                                [(#\≍) "$\\asymp$"]
                                [(#\∥) "$\\parallel$"]
                                [(#\⊂) "$\\subset$"]
                                [(#\⊃) "$\\supset$"]
                                [(#\≈) "$\\approx$"]
                                [(#\⋈) "$\\bowtie$"]
                                [(#\⊆) "$\\subseteq$"]
                                [(#\⊇) "$\\supseteq$"]
                                [(#\≌) "$\\cong$"]
                                [(#\⊏) "$\\sqsubset$"]
                                [(#\⊐) "$\\sqsupset$"]
                                [(#\≠) "$\\neq$"]
                                [(#\⌣) "$\\smile$"]
                                [(#\⊑) "$\\sqsubseteq$"]
                                [(#\⊒) "$\\sqsupseteq$"]
                                [(#\≐) "$\\doteq$"]
                                [(#\⌢) "$\\frown$"]
                                [(#\∈) "$\\in$"]
                                [(#\∉) "$\\not\\in$"]
                                [(#\∋) "$\\ni$"]
                                [(#\∝) "$\\propto$"]
                                [(#\⊢) "$\\vdash$"]
                                [(#\⊣) "$\\dashv$"]    
                                [(#\☠) "$\\skull$"]
                                [(#\☺) "$\\smiley$"]
                                [(#\☻) "$\\blacksmiley$"]
                                [(#\☹) "$\\frownie$"]
                                [(#\ø) "{\\o}"]
                                [(#\Ø) "{\\O}"]
                                [(#\ł) "{\\l}"]
                                [(#\Ł) "{\\L}"]
                                [(#\uA7) "{\\S}"]
                                [(#\⟦ #\〚) "$[\\![$"]
                                [(#\⟧ #\〛) "$]\\!]$"]
                                [(#\↦) "$\\mapsto$"]
                                [(#\⊤) "$\\top$"]
                                [(#\¥) "{\\textyen}"]
                                [(#\™) "{\\texttrademark}"]
                                [(#\®) "{\\textregistered}"]
                                [(#\©) "{\\textcopyright}"]
                                [(#\u2070) "$^0$"]
                                [(#\u00b9) "$^1$"]
                                [(#\u00b2) "$^2$"]
                                [(#\u00b3) "$^3$"]
                                [(#\u2074) "$^4$"]
                                [(#\u2075) "$^5$"]
                                [(#\u2076) "$^6$"]
                                [(#\u2077) "$^7$"]
                                [(#\u2078) "$^8$"]
                                [(#\u2079) "$^9$"]
                                [(#\u207a) "$^+$"]
                                [(#\u207b) "$^-$"]
                                [(#\⋖) "$\\precdot$"]
                                [(#\⋗) "$\\succdot$"]
                                [(#\⋮) "\\vdots"]
                                [(#\⋱) "$\\ddots$"]
                                [(#\⋯) "$\\cdots$"]
                                [(#\⋯) "\\hdots"]
                                [else
                                 (cond
                                  [(char<=? #\uAC00 c #\uD7AF) ; Korean Hangul
                                   (format "\\begin{CJK}{UTF8}{mj}~a\\end{CJK}" c)]
                                  [else
                                   ;; Detect characters that can be formed with combining characters
                                   ;; and translate them to Latex combinations:
                                   (define s (string-normalize-nfd (string c)))
                                   (define len (string-length s))
                                   (cond
                                    [(len . > . 1)
                                     (define combiner (case (string-ref s (sub1 len))
                                                        [(#\u300) "\\`{~a}"]
                                                        [(#\u301) "\\'{~a}"]
                                                        [(#\u302) "\\^{~a}"]
                                                        [(#\u303) "\\~~{~a}"]
                                                        [(#\u304) "\\={~a}"]
                                                        [(#\u306) "\\u{~a}"]
                                                        [(#\u307) "\\.{~a}"]
                                                        [(#\u308) "\\\"{~a}"]
                                                        [(#\u30a) "\\r{~a}"]
                                                        [(#\u30b) "\\H{~a}"]
                                                        [(#\u30c) "\\v{~a}"]
                                                        [(#\u327) "\\c{~a}"]
                                                        [(#\u328) "\\k{~a}"]
                                                        [else #f]))
                                     (define base (string-normalize-nfc (substring s 0 (sub1 len))))
                                     (if (and combiner
                                              (= 1 (string-length base)))
                                         (format combiner (char-loop (string-ref base 0)))
                                         c)]
                                    [else c])])]))
                          c)])))
                (loop (add1 i))))))]))
    
    
    (define/private (box-character c [line-thickness 1])
      (define (combine . args) 
        (apply string-append
               "\\setlength{\\unitlength}{0.05em}"
               (if (= line-thickness 1)
                   ""
                   (format "\\linethickness{~apt}" (* 0.4 line-thickness)))
               (filter (λ (x) (not (regexp-match #rx"^[ \n]*$" x)))
                       (flatten args))))
      (define (adjust % v) 
        (define num (* % (/ v 10) 10))
        (define i-part (floor num))
        (define d-part (floor (* 10 (- num i-part))))
        (format "~a.~a" i-part d-part))
      (define (x v) (adjust 1 v))
      (define (y v) (adjust 6/4 v))
      (define upper-horizontal @list{\put(@x[0],@y[6]){\line(1,0){@x[10]}}})
      (define mid-horizontal @list{\put(@x[0],@y[5]){\line(1,0){@x[10]}}})
      (define lower-horizontal @list{\put(@x[0],@y[4]){\line(1,0){@x[10]}}})
      (define righter-vertical @list{\put(@x[6],@y[10]){\line(0,-1){@y[10]}}})
      (define mid-vertical @list{\put(@x[5],@y[10]){\line(0,-1){@y[10]}}})
      (define lefter-vertical @list{\put(@x[4],@y[10]){\line(0,-1){@y[10]}}})
      (define bottom-right @list{\put(@x[6],@y[4]){\line(1,0){@x[4]}}
                                 \put(@x[6],@y[0]){\line(0,1){@y[4]}}})
      (define bottom-left @list{\put(@x[0],@y[4]){\line(1,0){@x[4]}}
                                \put(@x[4],@y[0]){\line(0,1){@y[4]}}})
      (define upper-right @list{\put(@x[6],@y[6]){\line(1,0){@x[4]}}
                                \put(@x[6],@y[10]){\line(0,-1){@y[4]}}})
      (define upper-left @list{\put(@x[0],@y[6]){\line(1,0){@x[4]}}
                               \put(@x[4],@y[10]){\line(0,-1){@y[4]}}})
      (define header @list{\begin{picture}(@x[10],@y[10])(0,0)})
      (define footer @list{\end{picture}})
                              
      (case c
        [(#\╔)
         @combine{@header
                   \put(@x[4],@y[6]){\line(1,0){@x[6]}}
                   \put(@x[4],@y[0]){\line(0,1){@y[6]}}
                   @bottom-right
                   @footer}]
        [(#\═) @combine{@header
                         @upper-horizontal
                         @lower-horizontal
                         @footer}]
        [(#\╗) @combine{@header
                         \put(@x[0],@y[6]){\line(1,0){@x[6]}}
                         \put(@x[6],@y[0]){\line(0,1){@y[6]}}
                         @bottom-left
                         @footer}]
        [(#\║) @combine{@header
                         @lefter-vertical
                         @righter-vertical
                         @footer}]
        [(#\╚) @combine{@header
                         @upper-right
                         \put(@x[4],@y[4]){\line(1,0){@x[6]}}
                         \put(@x[4],@y[10]){\line(0,-1){@y[6]}}
                         @footer}]
        [(#\╝)
         @combine{@header
                   @upper-left
                   \put(@x[0],@y[4]){\line(1,0){@x[6]}}
                   \put(@x[6],@y[10]){\line(0,-1){@y[6]}}
                   @footer}]
        [(#\╣)
         @combine{@header
                   @upper-left
                   @bottom-left
                   @righter-vertical
                   @footer}]
        [(#\╠)
         @combine{@header
                   @upper-right
                   @bottom-right
                   @lefter-vertical
                   @footer}]
        [(#\╩)
         @combine{@header
                   @upper-right
                   @upper-left
                   @lower-horizontal
                   @footer}]
        [(#\╦)
         @combine{@header
                   @bottom-right
                   @bottom-left
                   @upper-horizontal
                   @footer}]
        [(#\╬)
          @combine{@header
                   @upper-left
                   @bottom-left
                   @upper-right
                   @bottom-right
                   @footer}]
        [(#\┌ #\┏)
         @combine{@header
                   \put(@x[5],@y[5]){\line(1,0){@x[5]}}
                   \put(@x[5],@y[0]){\line(0,1){@y[5]}}
                   @footer}]
        [(#\─ #\━) @combine{@header
                        @mid-horizontal
                        @footer}]
        [(#\┐ #\┓) @combine{@header
                        \put(@x[0],@y[5]){\line(1,0){@x[5]}}
                        \put(@x[5],@y[0]){\line(0,1){@y[5]}}
                        @footer}]
        [(#\│ #\┃) @combine{@header
                        @mid-vertical
                        @footer}]
        [(#\└ #\┗) @combine{@header
                        \put(@x[5],@y[5]){\line(1,0){@x[5]}}
                        \put(@x[5],@y[10]){\line(0,-1){@y[5]}}
                        @footer}]
        [(#\┘ #\┛)
         @combine{@header
                  \put(@x[0],@y[5]){\line(1,0){@x[5]}}
                  \put(@x[5],@y[10]){\line(0,-1){@y[5]}}
                  @footer}]
        [(#\┤ #\┫)
         @combine{@header
                  \put(@x[0],@y[5]){\line(1,0){@x[5]}}
                  @mid-vertical
                  @footer}]
        [(#\├ #\┣)
         @combine{@header
                  \put(@x[5],@y[5]){\line(1,0){@x[5]}}
                  @mid-vertical
                  @footer}]
        [(#\┴ #\┻)
         @combine{@header
                  \put(@x[5],@y[10]){\line(0,-1){@y[5]}}
                  @mid-horizontal
                  @footer}]
        [(#\┬ #\┳)
         @combine{@header
                  \put(@x[5],@y[5]){\line(0,-1){@y[5]}}
                  @mid-horizontal
                  @footer}]
        [(#\┼ #\╋)
          @combine{@header
                   @mid-horizontal
                   @mid-vertical
                   @footer}]))

    ;; ----------------------------------------

    (define/override (table-of-contents sec ri)
      ;; FIXME: isn't local to the section
      (make-toc-paragraph plain null))

    (define/override (local-table-of-contents part ri style)
      (make-paragraph plain null))))
