◊(Local Yarn Code "Diff")

@section{Markup reference}

These are the tags that can be used in any of @italic{The Local Yarn}’s Pollen documents (articles,
etc).

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

@margin-note{The @code{title} function is not actually defined in @filepath{pollen.rkt} or anywhere
else. In Pollen, any undefined function @tt{title} defaults to @racket[(default-tag-function
title)], which is what I want. It is documented here because its presence or absence has
side-effects on the display of the article.}

Supplies a title for the document. You can use any otherwise-valid markup within the title tag. 

Titles are optional; if you don’t specify a title, the article will appear without one. This is
a feature!
}

@deftogether[(@defproc[(excerpt [elements xexpr?] ...) txexpr?]
              @defproc[(excerpt* [elements xexpr?] ...) txexpr?])]{

Specify an excerpt to be used when the article or note included in an excerpt-style listing (such as
the blog). The contents of @racket[excerpt] will be extracted out of the article and note and only
appear in listings; if @racket[excerpt*] is used, its contents will be left in place in the
article/note and @emph{reused} as the excerpt in listings.

}

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

Wrap text in a paragraph. You almost never need to use this tag explicitly; 
just separate paragraphs by an empty line.