lua2md

Fun and braindead code documentation. Reads in annotated lua code and writes out markdown-formatted documentation. lua2md is documented using itself ;p

Documenting Code

Documentation lines start with --- followed by a space, except when they are blank lines, in which case you don't need the space. Documentation lines are run through markdown and output directly. Code (everything that's not documentation) is converted into markdown code blocks.

--- This is a documentation line and will be converted to markdown
--- paragraphs
This is code which is output as a code block.

Code blocks have leading and trailing blank lines removed, and code blocks which end up being empty are not output.

For example, the following:

--- Empty code blocks


--- are omitted.

outputs as

Empty code blocks

are omitted.

Note that although the code block is not shown, the break in documentation still acts as a paragraph break.

Usage

Currently lua2md always reads source code from standard input and writes documentation to standard output. As an example, lua2md's own documentation can be generated with:

lua lua2md.lua < lua2md.lua > README.md

Implementation

doc(line)

If line contains documentation, then returns the markdown to output, otherwise returns false.

function doc(line)
  return line:match('^%s*%-%-%- (.*)$') or line:match('^%s*%-%-%-$') and ""
end

code(line)

If line contains code, then returns the markdown to output, otherwise returns false.

function code(line)
  return not doc(line) and '    ' .. line
end

is_blank(line)

Returns true if line is a blank line, false otherwise.

function is_blank(line)
  return line:match('^%s*$') and true
end

parse_doc(line)

Parses a documentation block.

function parse_doc(line)
  local docline = doc(line)
  while docline do
    print(docline)
    line = io.read()
    if not line then return end
    docline = doc(line)
  end
  print()
  return parse_code(line)
end

parse_code(line)

Parses a code block.

function parse_code(line)
  while is_blank(line) do
    line = io.read()
    if not line then return end
  end

  local blanks = {}
  local codeline = code(line)
  while codeline do
    if is_blank(codeline) then
      table.insert(blanks, codeline)
    else
      if #blanks ~= 0 then
        print(table.concat(blanks, '\n'))
        blanks = {}
      end
      print(codeline)
    end

    line = io.read()
    if not line then return end
    codeline = code(line)
  end
  print()
  return parse_doc(line)
end

initialization

Tests whether the lua document starts with documentation or code, then starts the corresponding parser.

local line = io.read()
if not line then return end
if doc(line) then
  parse_doc(line)
else
  parse_code(line)
end

License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

henkboom/lua2md