Since writers are normally only used synchronously (i.e. to write one document
at a time), we don't guard modifications to their internal
state (e.g. temporarily replacing the string.Builder in WriteNodesAsString)
against race conditions.
The package global `orgWriter` and corresponding use cases of it (`org.String`,
`$node.String`) break that pattern - the writer is potentially used from
multiple go routines at the same time. This results in race conditions that
manifest as error messages like e.g.
could not write output: runtime error: invalid memory address or nil pointer dereference. Using unrendered content.
Additionally, since we catch panics in `Document.Write`, the corresponding
stack trace is lost and dependents of go-org never know what hit them.
As using a writer across simultaneously across go routines is not a standard
pattern, we'll sync the use of the global `orgWriter` instead of trying to make
the actual writer threadsafe; less code noise for the common use case.
WriteNodesAsString is simple enough to implement but exposing it is helpful in
the implementation of extending writers and we don't aim to keep writer a small
interface so let's expose it.
- Remove unused footnote section title option
- Move away from maintaining a list of footnotes in the document (only needed
for html export, potential maintainance overhead when modifying the document)
and rather only build it on export when required.
- HTML export: Rename all footnotes to numbers (so we can support anonymous
footnote references by assigning them a number) and export footnotes in order
of reference, not definition. The implementation of this makes it natural to
also stop exporting unused footnote definitions so we do that as well.
Being able to very easily get the original [1] Org mode content seems like
something that will come up quite often and is very little code.
[1] it's not really the original content, but rather the pretty printed version
of that - as the semantics don't change it shouldn't matter.
- Footnotes separator rather than headline to get around i18n
- Warn on footnote redefinition
- Do not export footnote definitions at point of definition, only in the
footnote section.
- Do not automatically exclude Footnotes section to get around possibly hiding
other content of such a section - and i18n.
The user has the choice of explicitly hiding the section via a :noexport:
tag.
and some other refactoring
Until now the footnotes section was parsed but not included in the resulting
AST - his required rebuilding it in the OrgWriter. It feels cleaner to include
it in the AST and only exclude it in the export
