rocco/lib/rocco.rb
Mike West 9d49139090 Fixing block comment highlighting for block-only languages
Languages without single-line comments (CSS) explode when running
through `highlight`, as the `DIVIDER` mechanism doesn't deal well with
`nil` comment characters.  I've reworked the mechanism such that it
uses multi-line comments when single-line comments aren't available.
2010-11-25 16:12:28 +01:00

412 lines
16 KiB
Ruby

# **Rocco** is a Ruby port of [Docco][do], the quick-and-dirty,
# hundred-line-long, literate-programming-style documentation generator.
#
# Rocco reads Ruby source files and produces annotated source documentation
# in HTML format. Comments are formatted with [Markdown][md] and presented
# alongside syntax highlighted code so as to give an annotation effect.
# This page is the result of running Rocco against [its own source file][so].
#
# Most of this was written while waiting for [node.js][no] to build (so I
# could use Docco!). Docco's gorgeous HTML and CSS are taken verbatim.
# The main difference is that Rocco is written in Ruby instead of
# [CoffeeScript][co] and may be a bit easier to obtain and install in
# existing Ruby environments or where node doesn't run yet.
#
# Install Rocco with Rubygems:
#
# gem install rocco
#
# Once installed, the `rocco` command can be used to generate documentation
# for a set of Ruby source files:
#
# rocco lib/*.rb
#
# The HTML files are written to the current working directory.
#
# [no]: http://nodejs.org/
# [do]: http://jashkenas.github.com/docco/
# [co]: http://coffeescript.org/
# [md]: http://daringfireball.net/projects/markdown/
# [so]: http://github.com/rtomayko/rocco/blob/master/lib/rocco.rb#commit
#### Prerequisites
# We'll need a Markdown library. [RDiscount][rd], if we're lucky. Otherwise,
# issue a warning and fall back on using BlueCloth.
#
# [rd]: http://github.com/rtomayko/rdiscount
begin
require 'rdiscount'
rescue LoadError => boom
warn "WARNING: #{boom}. Trying bluecloth."
require 'bluecloth'
Markdown = BlueCloth
end
# We use [{{ mustache }}](http://defunkt.github.com/mustache/) for
# HTML templating.
require 'mustache'
# We use `Net::HTTP` to highlight code via <http://pygments.appspot.com>
require 'net/http'
# Code is run through [Pygments](http://pygments.org/) for syntax
# highlighting. If it's not installed, locally, use a webservice.
include FileTest
if !ENV['PATH'].split(':').any? { |dir| executable?("#{dir}/pygmentize") }
warn "WARNING: Pygments not found. Using webservice."
end
#### Public Interface
# `Rocco.new` takes a source `filename`, an optional list of source filenames
# for other documentation sources, an `options` hash, and an optional `block`.
# The `options` hash respects three members:
#
# * `:language`: specifies which Pygments lexer to use if one can't be
# auto-detected from the filename. _Defaults to `ruby`_.
#
# * `:comment_chars`, which specifies the comment characters of the
# target language. _Defaults to `#`_.
#
# * `:template_file`, which specifies a external template file to use
# when rendering the final, highlighted file via Mustache. _Defaults
# to `nil` (that is, Mustache will use `./lib/rocco/layout.mustache`)_.
#
class Rocco
VERSION = '0.5'
def initialize(filename, sources=[], options={}, &block)
@file = filename
@sources = sources
# When `block` is given, it must read the contents of the file using
# whatever means necessary and return it as a string. With no `block`,
# the file is read to retrieve data.
@data =
if block_given?
yield
else
File.read(filename)
end
defaults = {
:language => 'ruby',
:comment_chars => '#',
:template_file => nil
}
@options = defaults.merge(options)
# If we detect a language
if detect_language() != "text"
# then assign the detected language to `:language`, and look for
# comment characters based on that language
@options[:language] = detect_language()
@options[:comment_chars] = generate_comment_chars()
# If we didn't detect a language, but the user provided one, use it
# to look around for comment characters to override the default.
elsif @options[:language] != defaults[:language]
@options[:comment_chars] = generate_comment_chars()
# If neither is true, then convert the default comment character string
# into the comment_char syntax (we'll discuss that syntax in detail when
# we get to `generate_comment_chars()` in a moment.
else
@options[:comment_chars] = { :single => @options[:comment_chars], :multi => nil }
end
# Turn `:comment_chars` into a regex matching a series of spaces, the
# `:comment_chars` string, and the an optional space. We'll use that
# to detect single-line comments.
@comment_pattern = Regexp.new("^\\s*#{@options[:comment_chars][:single]}\s?")
# `parse()` the file contents stored in `@data`. Run the result through `split()`
# and that result through `highlight()` to generate the final section list.
@sections = highlight(split(parse(@data)))
end
# The filename as given to `Rocco.new`.
attr_reader :file
# The merged options array
attr_reader :options
# A list of two-tuples representing each *section* of the source file. Each
# item in the list has the form: `[docs_html, code_html]`, where both
# elements are strings containing the documentation and source code HTML,
# respectively.
attr_reader :sections
# A list of all source filenames included in the documentation set. Useful
# for building an index of other files.
attr_reader :sources
# Generate HTML output for the entire document.
require 'rocco/layout'
def to_html
Rocco::Layout.new(self, @options[:template_file]).render
end
# Helper Functions
# ----------------
# Returns `true` if `pygmentize` is available locally, `false` otherwise.
def pygmentize?
# Memoize the result
if @_pygmentize.nil?
@_pygmentize = ENV['PATH'].split(':').any? { |dir| executable?("#{dir}/pygmentize") }
end
@_pygmentize
end
# If `pygmentize` is available, we can use it to autodetect a file's
# language based on its filename. Filenames without extensions, or with
# extensions that `pygmentize` doesn't understand will return `text`.
# We'll also return `text` if `pygmentize` isn't available.
#
# We'll memoize the result, as we'll call this a few times.
def detect_language
@_language ||= begin
if pygmentize?
lang = %x[pygmentize -N #{@file}].strip!
else
"text"
end
end
end
# Given a file's language, we should be able to autopopulate the
# `comment_chars` variables for single-line comments. If we don't
# have comment characters on record for a given language, we'll
# use the user-provided `:comment_char` option (which defaults to
# `#`).
#
# Comment characters are listed as:
#
# { :single => "//", :multi_start => "/**", :multi_middle => "*", :multi_end => "*/" }
#
# `:single` denotes the leading character of a single-line comment.
# `:multi_start` denotes the string that should appear alone on a
# line of code to begin a block of documentation. `:multi_middle`
# denotes the leading character of block comment content, and
# `:multi_end` is the string that ought appear alone on a line to
# close a block of documentation. That is:
#
# /** [:multi][:start]
# * [:multi][:middle]
# ...
# * [:multi][:middle]
# */ [:multi][:end]
#
# If a language only has one type of comment, the missing type
# should be assigned `nil`.
#
# At the moment, we're only returning `:single`. Consider this
# groundwork for block comment parsing.
def generate_comment_chars
@_commentchar ||= begin
language = @options[:language]
comment_styles = {
"bash" => { :single => "#", :multi => nil },
"c" => { :single => "//", :multi => { :start => "/**", :middle => "*", :end => "*/" } },
"coffee-script" => { :single => "#", :multi => { :start => "###", :middle => nil, :end => "###" } },
"cpp" => { :single => "//", :multi => { :start => "/**", :middle => "*", :end => "*/" } },
"css" => { :single => nil, :multi => { :start => "/**", :middle => "*", :end => "*/" } },
"java" => { :single => "//", :multi => { :start => "/**", :middle => "*", :end => "*/" } },
"js" => { :single => "//", :multi => { :start => "/**", :middle => "*", :end => "*/" } },
"lua" => { :single => "--", :multi => nil },
"python" => { :single => "#", :multi => { :start => '"""', :middle => nil, :end => '"""' } },
"rb" => { :single => "#", :multi => { :start => '=begin', :middle => nil, :end => '=end' } },
"scheme" => { :single => ";;", :multi => nil },
}
if comment_styles[language]
comment_styles[language]
else
{ :single => @options[:comment_chars], :multi => nil }
end
end
end
# Internal Parsing and Highlighting
# ---------------------------------
# Parse the raw file data into a list of two-tuples. Each tuple has the
# form `[docs, code]` where both elements are arrays containing the
# raw lines parsed from the input file, comment characters stripped.
def parse(data)
sections = []
docs, code = [], []
lines = data.split("\n")
# The first line is ignored if it is a shebang line. We also ignore the
# PEP 263 encoding information in python sourcefiles, and the similar ruby
# 1.9 syntax.
lines.shift if lines[0] =~ /^\#\!/
lines.shift if lines[0] =~ /coding[:=]\s*[-\w.]+/ and [ "python", "rb" ].include? @options[:language]
# To detect both block comments and single-line comments, we'll set
# up a tiny state machine, and loop through each line of the file.
# This requires an `in_comment_block` boolean, and a few regular
# expressions for line tests.
in_comment_block = false
single_line_comment, block_comment_start, block_comment_mid, block_comment_end = nil, nil, nil, nil
if not @options[:comment_chars][:single].nil?
single_line_comment = Regexp.new("^\\s*#{Regexp.escape(@options[:comment_chars][:single])}\\s?")
end
if not @options[:comment_chars][:multi].nil?
block_comment_start = Regexp.new("^\\s*#{Regexp.escape(@options[:comment_chars][:multi][:start])}\\s*$")
block_comment_end = Regexp.new("^\\s*#{Regexp.escape(@options[:comment_chars][:multi][:end])}\\s*$")
if @options[:comment_chars][:multi][:middle]
block_comment_mid = Regexp.new("^\\s*#{Regexp.escape(@options[:comment_chars][:multi][:middle])}\\s?")
end
end
lines.each do |line|
# If we're currently in a comment block, check whether the line matches
# the _end_ of a comment block.
if in_comment_block
if block_comment_end && line.match( block_comment_end )
in_comment_block = false
else
docs << line.sub( block_comment_mid || '', '' )
end
# Otherwise, check whether the line matches the beginning of a block, or
# a single-line comment all on it's lonesome. In either case, if there's
# code, start a new section
else
if block_comment_start && line.match( block_comment_start )
in_comment_block = true
if code.any?
sections << [docs, code]
docs, code = [], []
end
elsif single_line_comment && line.match( single_line_comment )
if code.any?
sections << [docs, code]
docs, code = [], []
end
docs << line.sub( single_line_comment || '', '' )
else
code << line
end
end
end
sections << [docs, code] if docs.any? || code.any?
normalize_leading_spaces( sections )
end
# Normalizes documentation whitespace by checking for leading whitespace,
# removing it, and then removing the same amount of whitespace from each
# succeeding line. That is:
#
# def func():
# """
# Comment 1
# Comment 2
# """
# print "omg!"
#
# should yield a comment block of `Comment 1\nComment 2` and code of
# `def func():\n print "omg!"`
def normalize_leading_spaces( sections )
sections.map do |section|
if section.any? && section[0].any?
leading_space = section[0][0].match( "^\s+" )
if leading_space
section[0] = section[0].map{ |line| line.sub( /^#{leading_space.to_s}/, '' ) }
end
end
section
end
end
# Take the list of paired *sections* two-tuples and split into two
# separate lists: one holding the comments with leaders removed and
# one with the code blocks.
def split(sections)
docs_blocks, code_blocks = [], []
sections.each do |docs,code|
docs_blocks << docs.join("\n")
code_blocks << code.map do |line|
tabs = line.match(/^(\t+)/)
tabs ? line.sub(/^\t+/, ' ' * tabs.captures[0].length) : line
end.join("\n")
end
[docs_blocks, code_blocks]
end
# Take the result of `split` and apply Markdown formatting to comments and
# syntax highlighting to source code.
def highlight(blocks)
docs_blocks, code_blocks = blocks
# Combine all docs blocks into a single big markdown document with section
# dividers and run through the Markdown processor. Then split it back out
# into separate sections.
markdown = docs_blocks.join("\n\n##### DIVIDER\n\n")
docs_html = Markdown.new(markdown, :smart).
to_html.
split(/\n*<h5>DIVIDER<\/h5>\n*/m)
# Combine all code blocks into a single big stream with section dividers and
# run through either `pygmentize(1)` or <http://pygments.appspot.com>
if not @options[:comment_chars][:single].nil?
divider_input = "\n\n#{@options[:comment_chars][:single]} DIVIDER\n\n"
divider_output = /\n*<span class="c.?">#{Regexp.escape(@options[:comment_chars][:single])} DIVIDER<\/span>\n*/m
else
divider_input = "\n\n#{@options[:comment_chars][:multi][:start]}\nDIVIDER\n#{@options[:comment_chars][:multi][:end]}\n\n"
divider_output = /\n*<span class="c.?">#{Regexp.escape(@options[:comment_chars][:multi][:start])}<\/span>\n<span class="c.?">DIVIDER<\/span>\n<span class="c.?">#{Regexp.escape(@options[:comment_chars][:multi][:end])}<\/span>\n*/m
end
code_stream = code_blocks.join( divider_input )
if pygmentize?
code_html = highlight_pygmentize(code_stream)
else
code_html = highlight_webservice(code_stream)
end
# Do some post-processing on the pygments output to split things back
# into sections and remove partial `<pre>` blocks.
code_html = code_html.
split(divider_output).
map { |code| code.sub(/\n?<div class="highlight"><pre>/m, '') }.
map { |code| code.sub(/\n?<\/pre><\/div>\n/m, '') }
# Lastly, combine the docs and code lists back into a list of two-tuples.
docs_html.zip(code_html)
end
# We `popen` a read/write pygmentize process in the parent and
# then fork off a child process to write the input.
def highlight_pygmentize(code)
code_html = nil
open("|pygmentize -l #{@options[:language]} -O encoding=utf-8 -f html", 'r+') do |fd|
pid =
fork {
fd.close_read
fd.write code
fd.close_write
exit!
}
fd.close_write
code_html = fd.read
fd.close_read
Process.wait(pid)
end
code_html
end
# Pygments is not one of those things that's trivial for a ruby user to install,
# so we'll fall back on a webservice to highlight the code if it isn't available.
def highlight_webservice(code)
Net::HTTP.post_form(
URI.parse('http://pygments.appspot.com/'),
{'lang' => @options[:language], 'code' => code}
).body
end
end
# And that's it.