The indirection uses a "local-redirect.js" script to rewrite
the document links to local links within the browser. This mechanism
is a step towards distributing compiled packages that include
already-built documentation, where paths to other documentation
can be different than in the build environment.
If the links are not rewritten, they are queries to
"pkg-docs.racket-lang.org", with the idea tha such a server will exist
for reading all package documentation online. Also, a package's
documentation that refer to documentation for uninstalled packages,
in which case the corresponding links will not get rewritten and
will continue to point to the server.
Rendering the "local-redirect.js" script spends a lot of time just
converting among different path formats. Various library changes in
this commit are aimed at speed up those conversions, but the big
improvement came from a `path->url-string' that shortcuts conversion
os simple Unix paths.
When a tag is serializable but not `write'--`read' invariant,
then it needs to be serialized and deserialized.
Also, clarify and check in `tag?' that a tag should be
serializable.
The `xref' produced by `setup/xref' uses the database to delay
loading "out.sxref"s, which cuts 64-bit DrRacket's initial
footprint by around 50MB (i.e., about 20%).
Also, add 'lsquo as allowed content.
Omitting the ` conversion in the first place was over-conservative.
There's a backward-compatibility issue with this addition (i.e., a
document might contain a backquote in a decoded context that is
meant to be rendered as a backquote), but the potential problems
seem minor.
For example, if you make a multi-column table with a
`racketblock' in each column, then the columns size
to fit the code --- instead of forcing the table width
to match the page width and forcing each column to take
an equal share width.
