...the ScriptingEngine fields. Instead of separate fields for
custom readers and writers, we now have a single function
that loads any number of "components" from a script: these
may be custom readers, custom writers, templates for writers,
or extension configs. (Note: it's possible to have a custom
reader and a custom writer for a format together in the same file.)
This is primarily motivated by the need for a smoother check
for custom templates and extensions for `-D` and `--list-extensions`,
but it also seems more elegant.
This is a partial implementation of #8417.
T.P.Extensions [API change]:
+ Add CustomExtension constructor to Extension.
+ Remove Bounded, Enum instances for Extension.
+ Add `extensionsToList` function.
+ Revise `readExtension` so it can handle CustomExtension, and so
that it returns a Text rather than Maybe Text.
+ Add `showExtension`.
T.P.Format:
+ Revise error checking to handle CustomExtension.
This new module exports `pandocVersion` and `pandocVersionText`,
which are no longer exported from Text.Pandoc.Shared. [API change]
Also, we now set the `pandoc-version` variable centrally rather
than in the writers. One effect is the man writer now emits
a comment with the pandoc version (this was intended before,
judging from the template, but it didn't happen because the
vairable wasn't set).
Custom writers can define a default template via a global `Template`
function; the data directory is no longer searched for a default
template.
Writer authors can restore the old lookup behavior with
``` lua
Template = function ()
local template
return template.compile(template.default(PANDOC_SCRIPT_FILE))
end
```
Like custom readers, like writers, can define the set of supported
extensions by setting a global. E.g.:
``` lua
reader_extensions = {
smart = true,
citations = false,
}
```
Custom writers can define the extensions that they support via the
global `writer_extensions`. The variable's value must be a table with
all supported extensions as keys, and their default status as values.
E.g., the below specifies that the writer support the extensions `smart`
and `sourcepos`, but only the `smart` extension is enabled by default:
writer_extensions = {
smart = true,
sourcepos = false,
}
The module provides functions and types for format spec parsing and
processing.
The function `parseFormatSpec` was moved from Text.Pandoc.Extensions to
the new module and renamed to `parseFlavoredFormat`. It now operates in
a PandocMonad and is based on the updated types.
This makes T.P.Class more self-contained, and suitable for extraction
into a separate package if desired.
[API changes]
- T.P.Data is now an exported module, providing `readDataFile`,
`readDefaultDataFile` (both formerly provided by T.P.Class),
and also `getDataFileNames` (formerly unexported in
T.P.App.CommandLineOptions).
- T.P.Translations is now an exported module (along with
T.P.Translations.Types), providing `readTranslations`,
`getTranslations`, `setTranslations`, `translateTerm`,
`lookupTerm`, `readTranslations`, `Term(..)`, and `Translations`.
- T.P.Class: `readDataFile`, `readDefaultDataFile`, `setTranslations`,
and `translateTerm` are no longer exported.
`checkUserDataDir` is now exported.
- Text.Pandoc now exports Text.Pandoc.Data and `setTranslations`
and `translateTerm`.
New-style custom Lua writers can now define an alternative entry function
`BinaryWriter`. If a function with that name is defined, then pandoc
will treat the returned string as binary output. This allows to generate
formats like docx and odt with custom writers.
The `T.P.Lua.writeCustom` function changed to allow either a TextWriter
or ByteStringWriter to be returned. The global variables
`PANDOC_DOCUMENT` and `PANDOC_WRITER_OPTIONS` are no longer set when the
writer script is loaded. Both variables are still set in classic writers
before the conversion is started, so they can be used when they are
wrapped in functions.
The function can be used to convert a classic writer into a new-style
writer by setting it as the value of `Writer`:
``` lua
Writer = pandoc.write_classic
```
or to fully restore the old behavior:
``` lua
function Writer (doc, opts)
PANDOC_DOCUMENT = doc
PANDOC_WRITER_OPTIONS = opts
load(PANDOC_SCRIPT_FILE)()
return pandoc.write_classic(doc, opts)
end
```
John MacFarlane