When processing the environment variable
READthe string as an SEXP in the DSL, if it begins with a parenthesis
In the directory list format,
directories should come in pairs, each pair indicating a mapping directive.
Entries are separated
: (colon) on Unix platforms (including Mac and cygwin), and
; (semicolon) on other platforms (mainly, Windows).
The magic empty entry, if it comes in what would otherwise be the first entry in a pair, indicates the splicing of inherited configuration; the next entry (if any) then starts a new pair. If the second entry in a pair is empty, it indicates that the directory in the first entry is to be left untranslated (which has the same effect as if the directory had been repeated).
specify that outputs for things under directory /foo/
are translated to be under /bar/;
then include the inherited configuration;
then specify that outputs for things under directory /baz/ are not translated.