[cl-typesetting-devel] Should justification change inter-letter spacing?

[Peter Heslin]

A bit of experimentation shows that when setting a pathological
paragraph with ( :h-align :justified ), cl-typesetting achieves the
justification not only by stretching the inter-word space, as it
should do, but also by slightly stretching the inter-letter spacing,
which seems like very bad practice to me.  TeX never does this --
instead, it warns you and sticks text into the margin, which makes it
obvious that there is a problem.

Here is an example.

(defun test ()
  (with-document ()
    (draw-pages (compile-text ()
                              (paragraph (:h-align :justified)
                                "aaaaaaaaaaaaa"
                                "aaaaaaaaaaaaaa aaaaaaaaaaaaaaaaa aaaaaaaaa
aaaaaaaaaaa aaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaa
  aaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaa
  aaaaaaaaaaaaaaaaaa aaaaaaaaaaaa aaaaaaaaaaaaaaaaaaa aaaaaaaaaaaa
  aaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaa
"))
                :margins '(72 72 72 72))
    (when pdf:*page* (finalize-page pdf:*page*))
    (pdf:write-document #P"/tmp/test.pdf")))

Best wishes,

Peter