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|
require 'rdoc'
##
# RDoc::Markup parses plain text documents and attempts to decompose them into
# their constituent parts. Some of these parts are high-level: paragraphs,
# chunks of verbatim text, list entries and the like. Other parts happen at
# the character level: a piece of bold text, a word in code font. This markup
# is similar in spirit to that used on WikiWiki webs, where folks create web
# pages using a simple set of formatting rules.
#
# RDoc::Markup itself does no output formatting: this is left to a different
# set of classes.
#
# RDoc::Markup is extendable at runtime: you can add \new markup elements to
# be recognised in the documents that RDoc::Markup parses.
#
# RDoc::Markup is intended to be the basis for a family of tools which share
# the common requirement that simple, plain-text should be rendered in a
# variety of different output formats and media. It is envisaged that
# RDoc::Markup could be the basis for formatting RDoc style comment blocks,
# Wiki entries, and online FAQs.
#
# == Synopsis
#
# This code converts +input_string+ to HTML. The conversion takes place in
# the +convert+ method, so you can use the same RDoc::Markup converter to
# convert multiple input strings.
#
# require 'rdoc/markup/to_html'
#
# h = RDoc::Markup::ToHtml.new
#
# puts h.convert(input_string)
#
# You can extend the RDoc::Markup parser to recognise new markup
# sequences, and to add special processing for text that matches a
# regular expression. Here we make WikiWords significant to the parser,
# and also make the sequences {word} and \<no>text...</no> signify
# strike-through text. When then subclass the HTML output class to deal
# with these:
#
# require 'rdoc/markup'
# require 'rdoc/markup/to_html'
#
# class WikiHtml < RDoc::Markup::ToHtml
# def handle_special_WIKIWORD(special)
# "<font color=red>" + special.text + "</font>"
# end
# end
#
# m = RDoc::Markup.new
# m.add_word_pair("{", "}", :STRIKE)
# m.add_html("no", :STRIKE)
#
# m.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
#
# wh = WikiHtml.new
# wh.add_tag(:STRIKE, "<strike>", "</strike>")
#
# puts "<body>#{wh.convert ARGF.read}</body>"
#
#--
# Author:: Dave Thomas, dave@pragmaticprogrammer.com
# License:: Ruby license
class RDoc::Markup
SPACE = ?\s
# List entries look like:
# * text
# 1. text
# [label] text
# label:: text
#
# Flag it as a list entry, and work out the indent for subsequent lines
SIMPLE_LIST_RE = /^(
( \* (?# bullet)
|- (?# bullet)
|\d+\. (?# numbered )
|[A-Za-z]\. (?# alphabetically numbered )
)
\s+
)\S/x
LABEL_LIST_RE = /^(
( \[.*?\] (?# labeled )
|\S.*:: (?# note )
)(?:\s+|$)
)/x
##
# Take a block of text and use various heuristics to determine it's
# structure (paragraphs, lists, and so on). Invoke an event handler as we
# identify significant chunks.
def initialize
@am = RDoc::Markup::AttributeManager.new
@output = nil
end
##
# Add to the sequences used to add formatting to an individual word (such
# as *bold*). Matching entries will generate attributes that the output
# formatters can recognize by their +name+.
def add_word_pair(start, stop, name)
@am.add_word_pair(start, stop, name)
end
##
# Add to the sequences recognized as general markup.
def add_html(tag, name)
@am.add_html(tag, name)
end
##
# Add to other inline sequences. For example, we could add WikiWords using
# something like:
#
# parser.add_special(/\b([A-Z][a-z]+[A-Z]\w+)/, :WIKIWORD)
#
# Each wiki word will be presented to the output formatter via the
# accept_special method.
def add_special(pattern, name)
@am.add_special(pattern, name)
end
##
# We take a string, split it into lines, work out the type of each line,
# and from there deduce groups of lines (for example all lines in a
# paragraph). We then invoke the output formatter using a Visitor to
# display the result.
def convert(str, op)
lines = str.split(/\r?\n/).map { |line| Line.new line }
@lines = Lines.new lines
return "" if @lines.empty?
@lines.normalize
assign_types_to_lines
group = group_lines
# call the output formatter to handle the result
#group.each { |line| p line }
group.accept @am, op
end
private
##
# Look through the text at line indentation. We flag each line as being
# Blank, a paragraph, a list element, or verbatim text.
def assign_types_to_lines(margin = 0, level = 0)
while line = @lines.next
if line.blank? then
line.stamp :BLANK, level
next
end
# if a line contains non-blanks before the margin, then it must belong
# to an outer level
text = line.text
for i in 0...margin
if text[i] != SPACE
@lines.unget
return
end
end
active_line = text[margin..-1]
# Rules (horizontal lines) look like
#
# --- (three or more hyphens)
#
# The more hyphens, the thicker the rule
#
if /^(---+)\s*$/ =~ active_line
line.stamp :RULE, level, $1.length-2
next
end
# Then look for list entries. First the ones that have to have
# text following them (* xxx, - xxx, and dd. xxx)
if SIMPLE_LIST_RE =~ active_line
offset = margin + $1.length
prefix = $2
prefix_length = prefix.length
flag = case prefix
when "*","-" then :BULLET
when /^\d/ then :NUMBER
when /^[A-Z]/ then :UPPERALPHA
when /^[a-z]/ then :LOWERALPHA
else raise "Invalid List Type: #{self.inspect}"
end
line.stamp :LIST, level+1, prefix, flag
text[margin, prefix_length] = " " * prefix_length
assign_types_to_lines(offset, level + 1)
next
end
if LABEL_LIST_RE =~ active_line
offset = margin + $1.length
prefix = $2
prefix_length = prefix.length
next if handled_labeled_list(line, level, margin, offset, prefix)
end
# Headings look like
# = Main heading
# == Second level
# === Third
#
# Headings reset the level to 0
if active_line[0] == ?= and active_line =~ /^(=+)\s*(.*)/
prefix_length = $1.length
prefix_length = 6 if prefix_length > 6
line.stamp :HEADING, 0, prefix_length
line.strip_leading(margin + prefix_length)
next
end
# If the character's a space, then we have verbatim text,
# otherwise
if active_line[0] == SPACE
line.strip_leading(margin) if margin > 0
line.stamp :VERBATIM, level
else
line.stamp :PARAGRAPH, level
end
end
end
##
# Handle labeled list entries, We have a special case to deal with.
# Because the labels can be long, they force the remaining block of text
# over the to right:
#
# this is a long label that I wrote:: and here is the
# block of text with
# a silly margin
#
# So we allow the special case. If the label is followed by nothing, and
# if the following line is indented, then we take the indent of that line
# as the new margin.
#
# this is a long label that I wrote::
# here is a more reasonably indented block which
# will be attached to the label.
#
def handled_labeled_list(line, level, margin, offset, prefix)
prefix_length = prefix.length
text = line.text
flag = nil
case prefix
when /^\[/ then
flag = :LABELED
prefix = prefix[1, prefix.length-2]
when /:$/ then
flag = :NOTE
prefix.chop!
else
raise "Invalid List Type: #{self.inspect}"
end
# body is on the next line
if text.length <= offset then
original_line = line
line = @lines.next
return false unless line
text = line.text
for i in 0..margin
if text[i] != SPACE
@lines.unget
return false
end
end
i = margin
i += 1 while text[i] == SPACE
if i >= text.length then
@lines.unget
return false
else
offset = i
prefix_length = 0
if text[offset..-1] =~ SIMPLE_LIST_RE then
@lines.unget
line = original_line
line.text = ''
else
@lines.delete original_line
end
end
end
line.stamp :LIST, level+1, prefix, flag
text[margin, prefix_length] = " " * prefix_length
assign_types_to_lines(offset, level + 1)
return true
end
##
# Return a block consisting of fragments which are paragraphs, list
# entries or verbatim text. We merge consecutive lines of the same type
# and level together. We are also slightly tricky with lists: the lines
# following a list introduction look like paragraph lines at the next
# level, and we remap them into list entries instead.
def group_lines
@lines.rewind
in_list = false
wanted_type = wanted_level = nil
block = LineCollection.new
group = nil
while line = @lines.next
if line.level == wanted_level and line.type == wanted_type
group.add_text(line.text)
else
group = block.fragment_for(line)
block.add(group)
if line.type == :LIST
wanted_type = :PARAGRAPH
else
wanted_type = line.type
end
wanted_level = line.type == :HEADING ? line.param : line.level
end
end
block.normalize
block
end
##
# For debugging, we allow access to our line contents as text.
def content
@lines.as_text
end
public :content
##
# For debugging, return the list of line types.
def get_line_types
@lines.line_types
end
public :get_line_types
end
require 'rdoc/markup/fragments'
require 'rdoc/markup/inline'
require 'rdoc/markup/lines'
|
