Perl Some examples showing the possibilities using functional-perl.
gen-csv and csv_to_xml (and the shorter variant csv_to_xml_short) show how to stream number series into and from CSV files and into XML.
diff_to_html hows how to generate (X)HTML.
skip shows how to implement a sliding window (look-ahead) as a pure function (that can easily be tested) and then uses it for I/O
pdf-to-html is a practical, small and rather clean example reading directories and generating HTML. It also shows how to wrap non-functional Perl builtins (regex matching) in pure functions.
These are really just test suites, but perhaps still instructive:
predicates shows/tests FP::Predicates
Copy template to create your own script.
Htmlgen, the script that generates this website.
For a real program using these modules, see ml2json, although it still bundles a much older version of the functional-perl libraries (todo: update to use the current functional-perl instead)