◊(Local Yarn Code "Check-in [58810a67]")

Typeset contents as poetry, with line breaks preserved and the block centered on the longest line.
To set the whole block in italic, use @code{#:italic? #t} — otherwise, use @code{i} within the
block.

If the first element in an article is a @racket[verse] tag with the @racket[#:title] attribute
specified, that title is used as the article’s title if the normal @racket[title] tag is absent.

To cite a source, use @racket[attrib] immediately afterward.

}

@defproc[(blockquote [element xexpr?] ...) txexpr?]{

Surrounds a block quotation. To cite a source, use @racket[attrib] immediately afterward.

}

@defproc[(attrib [element xexpr?] ...) txexpr?]{

An attribution line, for citing a source for a block quotation, epigraph or poem.

}

@defproc[(blockcode [element xexpr?] ...) txexpr?]{

Typeset contents as a block of code using a monospace font. Line breaks are preserved.

}

@deftogether[(@defproc[(i      [element xexpr?] ...) txexpr?]
              @defproc[(em     [element xexpr?] ...) txexpr?]
              @defproc[(b      [element xexpr?] ...) txexpr?]
              @defproc[(mono   [element xexpr?] ...) txexpr?]
              @defproc[(strong [element xexpr?] ...) txexpr?]
              @defproc[(strike [element xexpr?] ...) txexpr?]
              @defproc[(ol     [element xexpr?] ...) txexpr?]
              @defproc[(ul     [element xexpr?] ...) txexpr?]
              @defproc[(item   [element xexpr?] ...) txexpr?]
              @defproc[(sup    [element xexpr?] ...) txexpr?]
              @defproc[(caps   [element xexpr?] ...) txexpr?]

(require (for-syntax racket/base
                     racket/syntax
                     syntax/parse
                     pollen/setup))

(require pollen/tag
         pollen/setup

         "cache.rkt"
         "tags-html.rkt"
         "snippets-html.rkt"
         "crystalize.rkt")

(provide (all-defined-out)
         (all-from-out "crystalize.rkt" "snippets-html.rkt" "cache.rkt"))

(poly-branch-tag excerpt)
(poly-branch-tag excerpt*)
    
(poly-branch-tag p)
(poly-branch-tag i)
(poly-branch-tag em)
(poly-branch-tag b)
(poly-branch-tag mono)
(poly-branch-tag strong)
(poly-branch-tag strike)
;(poly-branch-tag color)
(poly-branch-tag ol)
(poly-branch-tag ul)
(poly-branch-tag item)
(poly-branch-tag sup)

(poly-branch-tag saylines)
(poly-branch-kwargs-tag index)
(poly-branch-tag figure)
(poly-branch-tag figure-@2x)
(poly-branch-tag image-link)
(poly-branch-kwargs-tag blockcode)
(poly-branch-kwargs-tag verse)          ; [#:title ""] [#:italic "no"]
(poly-branch-tag attrib)

(poly-branch-tag link)
(poly-branch-tag url)
(poly-branch-tag xref)
(poly-branch-tag fn)
(poly-branch-tag fndef)

(poly-branch-kwargs-tag note)
(poly-branch-tag block)

;; Not yet implemented

         html-excerpt
         html-excerpt*
         html-item
         html-section
         html-subsection
         html-newthought
         html-caps
         html-mono
         html-center
         html-strike
         html-block
         html-blockcode
         html-index
         html-figure
         html-figure-@2x
         html-image-link
         html-dialogue
         html-say
         html-saylines
         html-verse
         html-attrib
         html-link
         html-xref
         html-url
         html-fn
         html-fndef
         html-note)

(define html-item (default-tag-function 'li))
(define html-section (default-tag-function 'h2))
(define html-subsection (default-tag-function 'h3))
(define html-newthought (default-tag-function 'span #:class "newthought"))
(define html-caps (default-tag-function 'span #:class "caps"))
(define html-center (default-tag-function 'div #:style "text-align: center"))
(define html-strike (default-tag-function 'span #:style "text-decoration: line-through"))
(define html-dialogue (default-tag-function 'dl #:class "dialogue"))
(define html-mono (default-tag-function 'samp))

(define (html-block . elements)
  `(section [[class "content-block"]] (div [[class "content-block-main"]] ,@elements)))

(define (html-root . elements)
  (invalidate-series)
  (define first-pass

  (let* ([title  (maybe-attr 'title attrs "")]
         [italic? (assoc 'italic? attrs)]
         [pre-attrs (cond [italic? '([class "verse"] [style "font-style: italic"])]
                          [else '([class "verse"])])]
         [pre-title (cond [(string>? title "") `(p [[class "verse-heading"]] ,title)]
                          [else ""])])
    `(div [[class "poem"]] ,pre-title (pre ,pre-attrs ,@elems))))

(define html-attrib (default-tag-function 'div #:class "attrib"))

;; (Private) Get the dimensions of an image file
(define (get-image-size filepath)
  (define bmp (make-object bitmap% filepath))
  (list (send bmp get-width) (send bmp get-height)))

;; (Private) Builds a path to an image in the [image-dir] subfolder of the current document's 

(define (decode-link-urls tx)
  (cond [(eq? (get-tag tx) 'link&)
         (let* ([url-ref (attr-ref tx 'ref)]
                [url (or (hash-ref link-urls url-ref #f)
                         (format "Missing reference: ~a" url-ref))])
           `(a [[href ,url]] ,@(get-elements tx)))]
        [else tx]))

;; Quick link to another article
(define (html-xref . elems)
  `(a [[href ,(format "~aarticles/~a.html" web-root (first elems))]
       [class "xref"]]
      ,@(rest elems)))

;; Footnotes
;;
;; Private use:
(define fn-names null)
(define fn-definitions (make-hash))
(define (fn-id x) (here-id (string-append x "_fn")))

   For now: By default, the title-less article is assumed to be the norm. On these, we use <H1> to 
   show the date in italics. */
article>h1 {
    font-size: ◊x-lineheight[1];
    line-height: ◊x-lineheight[1];
    margin: 0 0 ◊x-lineheight[1] 0;
    font-style: italic;
    font-weight: bold;
}

article.no-title>h1 {
    font-weight: normal
}

/* Titles non-bold, non-smallcaps by default. This can be overridden in document markup. */
h1.entry-title {
    margin: 0 0 0 0;
    text-transform: none;
    font-style: normal;
    line-height: 1.7rem;
}

h1.entry-title.note-full {
    font-weight: normal;
    font-feature-settings: "smcp" on, "liga" on, "clig" on, "dlig" on, "kern" on, "onum" on, "pnum" on;
}

/* This <SPAN> class is used in titles for Notes appended to earlier articles */
h1.entry-title .cross-reference {
    font-feature-settings: "smcp" off, "liga" on, "clig" on, "dlig" on, "kern" on, "onum" on, "pnum" on;
    font-style: italic;

    margin: ◊x-lineheight[1.0] 2em;
}

section.entry-content blockquote:first-child {
    margin-top: 0;
}





section.entry-content blockquote footer {
    margin-top: ◊x-lineheight[0.5];
    text-align: right;
    width: calc(100% + 2em);
}

section.entry-content h2 {
    font-size: 1.2rem;
    font-style: italic;

    padding: 0;
    text-indent: 0; 
}

code {
    font-size: 0.75rem;
    font-family: ◊mono-font;
    background: #ddd;
    border-radius: 0.2em;
}

pre {
    line-height: ◊derive-lineheight[7 #:per-lines 6];
    max-width: 100%;
    overflow-x: auto;
    tab-size: 4;
}

pre code {
    border: 0;
    background: none;

    font-size: 0.6rem;
}

pre.code {
    border: dotted #aaa 2px;
    padding-left: 0.2em;
    line-height: 0.7rem;
}

samp {
    font-family: ◊mono-font;
    font-size: 0.7rem;
}

pre.verse {
    font-family: ◊body-font;
    font-size: 1rem;
    line-height: ◊x-lineheight[1];
    width: auto;
    margin: ◊x-lineheight[1] auto;
    display: table;
    white-space: pre-wrap;
    /* Whitespace is preserved by the browser.
       Text will wrap when necessary, and on line breaks */
}

p.verse-heading {
    font-feature-settings: "smcp" on, "liga" on, "clig" on, "dlig" on, "kern" on, "onum" on, "pnum" on;
    text-align: center;
    font-size: 1.3rem;
}

div.attrib {
    text-align: right;
    font-size: .8rem;
    margin-top: -◊x-lineheight[0.5];
}
    
section.entry-content figure {
    margin: ◊x-lineheight[1] 0;
    padding: 0;
}

figure>a {