3.4 KiB
This is an implementation of John Gruber's markdown in Go. It is a translation of peg-markdown, written by John MacFarlane in C, into Go. It is using a modified version of Andrew J Snodgrass' PEG parser peg -- now supporting LEG grammars --, which is itself based on the parser used by peg-markdown.
Support for HTML output is implemented, but Groff and LaTeX output have not been ported. The output should be identical to that of peg-markdown.
A simple benchmark has been done by comparing the execution time of the Go binary (cmd/main.go) and the original C implementation's binary needed for processing a Markdown document, which had been created by concatenating ten Markdown syntax descriptions.
The C version is still around 1.2x faster than the Go version.
Installation
Provided you have a copy of Go 1, and git is available,
go get github.com/knieriem/markdown
should download and install the package according to your GOPATH settings.
See doc.go for an example how to use the package.
To create the command line program markdown, run
go build github.com/knieriem/markdown/cmd/markdown
the binary should then be available in the current directory.
To run the Markdown 1.0.3 test suite, type
make test
This will download peg-markdown, in case you have Mercurial and the hg-git extension available, build cmd/markdown, and run the test suite.
The test suite should fail on exactly one test – Ordered and unordered lists –, for the same reason which applies to peg-markdown, because the grammar is the same. See the original README for details.
Development
There is not yet a way to create a Go source file like
parser.leg.go automatically from another file, parser.leg,
when building packages and commands using the Go tool. To make
markdown installable using go get, parser.leg.go has
been added to the VCS.
Make parser will update parser.leg.go using leg, which
is part of knieriem/peg at github, if parser.leg has
been changed, or if the Go file is missing. If a copy of peg
is not yet present on your system, run
go get github.com/knieriem/peg
Then make parser should succeed.
Extensions
In addition to the extensions already present in peg-markdown,
this package also supports definition lists (option -dlists)
similar to the way they are described in the documentation of
PHP Markdown Extra.
Definitions (<dd>...</dd>) are implemented using ListTight
and ListLoose, on which bullet lists and ordered lists are based
already. If there is an empty line between the definition title and
the first definition, a loose list is expected, a tight list otherwise.
As definition item markers both : and ~ can be used.
Todo
-
Implement tables
-
Where appropriate, use more idiomatic Go code
Subdirectory Index
- cmd/markdown – command line program
markdown