A bibliography across files

Let each chapter declare its own sources and have one reference list assemble itself at the end. Add a chapter and the list grows — no central index to maintain.

Step 1 — A citation template

Declare the parameters in a header, then cite by position in prose.

~ shared/schema.wit

#cite(author, year): ::author:: (::year::) !!

@cite(Weil, 1952) renders Weil (1952). Pass values by name when one holds a comma: @cite(author: Weil, S., year: 1952).

Step 2 — Register an entry per chapter

+#name adds an entry to a list instead of redefining it. Put each source in the chapter that uses it; emphasis works inside an entry.

~ chapters/01-introduction.wit

reference ../shared/schema.wit

+#bibliography: Berger, J. (1972). _Ways of Seeing_. Penguin. !!

#chapter_one
(h2 Introduction h2)

Looking is never neutral, as @cite(Berger, 1972) showed.
chapter_one#

~ chapters/02-conclusion.wit

reference ../shared/schema.wit

+#bibliography: Weil, S. (1952). _Gravity and Grace_. Routledge. !!

#chapter_two
(h2 Conclusion h2)

Attention, after @cite(Weil, 1952), is a moral act.
chapter_two#

Step 3 — Render the list once

Entries from every referenced file collect into one list, in the order the files are met. Loop over it wherever the references belong — here, the master.

~ master.wit

reference ./chapters/01-introduction.wit
reference ./chapters/02-conclusion.wit

@chapter_one

@chapter_two

(h2 References h2)

@ol
(each @bibliography as entry)
(li @entry li)
(end)
ol@

Step 4 — Build the master

wit build master.wit --fragment

Result.

<h2>Introduction</h2>
<p>Looking is never neutral, as Berger (1972) showed.</p>
<h2>Conclusion</h2>
<p>Attention, after Weil (1952), is a moral act.</p>
<h2>References</h2>
<ol><li>Berger, J. (1972). <em>Ways of Seeing</em>. Penguin.</li>
<li>Weil, S. (1952). <em>Gravity and Grace</em>. Routledge.</li></ol>

Pitfalls

Order follows the references. Entries appear in the order the reference lines reach them, not alphabetically. Order the reference lines to order the list.
One entry per source. A file reached by several references still adds its entries once. Two chapters that both declare the same source add it twice — declare a shared source in a shared file.
Positional values can't hold commas. @cite(Weil, S., 1952) is E_TOO_MANY_ARGUMENTS; name the values instead.

Variations

Pin each idea to a source once — #weil_attention: @cite(Weil, 1952) !! in shared/sources.wit — and cite by idea in prose: as @weil_attention argued. Number entries with @entry.index (from 0) inside the loop for a custom style.