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.

The Go version is around 5x slower than the original C version. A marked speed improvement has been achieved by converting function preformat from concatenating strings to using bytes.Buffer. At other places, where this kind of modification had been tried, performance did not improve. Also, pre-allocating a large buffer for elements didn't show a significant difference from allocating elements one at a time.

Installation

Provided you have a recent copy of Go, and git is available,

goinstall github.com/knieriem/markdown

should install the package into $GOROOT/src/pkg/github.com/knieriem/markdown, and build it. During the build, a copy of knieriem/peg will be downloaded from github and compiled (make peg if done manually).

NOTE: At the moment, goinstall most likely will fail, as it does not use the package's Makefile, but generates its own, which is not sufficient as it does not know how to build parser.leg.go from parser.leg. As a workaround, after the failed goinstall, please do the following steps to finish the installation:

cd $GOROOT/src/pkg/github.com/knieriem/markdown
gomake install

See doc.go for an example how to use the package.

To update knieriem/peg run gomake update-peg. This will fetch available revisions from github, and remove the old leg binary.

To create the command line program markdown, run

cd $GOROOT/src/pkg/github.com/knieriem/markdown
gomake cmd

the binary should then be available in subdirectory cmd.

To run the Markdown 1.0.3 test suite, type

make mdtest

This will download peg-markdown, in case you have git available, build cmd/markdown, and run the test suite.

The test suite will fail on one test, for the same reason which applies to peg-markdown, because the grammar is the same. See the original README for details.

Todo

• Implement definition lists (work in progress), and perhaps tables

• Rename element key identifiers, so that they are not public

• Where appropriate, use more idiomatic Go code

Subdirectory Index

• peg – PEG parser generator (modified) from Andrew J Snodgrass

• peg/leg – LEG parser generator, based on PEG

• cmd – command line program markdown