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require 'ffi'
require 'stringio'
require 'cgi'
require 'set'
module CMark
extend FFI::Library
ffi_lib ['libcmark', 'cmark']
typedef :pointer, :node
enum :node_type, [:document, :blockquote, :list, :list_item,
:fenced_code, :indented_code, :html, :paragraph,
:atx_header, :setext_header, :hrule, :reference_def,
:str, :softbreak, :linebreak, :code, :inline_html,
:emph, :strong, :link, :image]
attach_function :cmark_free_nodes, [:node], :void
attach_function :cmark_node_unlink, [:node], :void
attach_function :cmark_markdown_to_html, [:string, :int], :string
attach_function :cmark_parse_document, [:string, :int], :node
attach_function :cmark_node_first_child, [:node], :node
attach_function :cmark_node_parent, [:node], :node
attach_function :cmark_node_next, [:node], :node
attach_function :cmark_node_previous, [:node], :node
attach_function :cmark_node_get_type, [:node], :node_type
attach_function :cmark_node_get_string_content, [:node], :string
attach_function :cmark_node_get_header_level, [:node], :int
end
class Node
attr_accessor :type, :children, :string_content, :header_level
def initialize(pointer)
if pointer.null?
return nil
end
@pointer = pointer
@type = CMark::cmark_node_get_type(pointer)
@children = []
first_child = CMark::cmark_node_first_child(pointer)
b = first_child
while !b.null?
@children << Node.new(b)
b = CMark::cmark_node_next(b)
end
@string_content = CMark::cmark_node_get_string_content(pointer)
@header_level = CMark::cmark_node_get_header_level(pointer)
if @type == :document
self.free
end
end
def self.parse_string(s)
Node.new(CMark::cmark_parse_document(s, s.bytesize))
end
def self.parse_file(f)
s = f.read()
self.parse_string(s)
end
def free
CMark::cmark_free_nodes(@pointer)
end
end
class Renderer
attr_reader :warnings
def initialize(stream = nil)
if stream
@stream = stream
@stringwriter = false
else
@stringwriter = true
@stream = StringIO.new
end
@need_blocksep = false
@warnings = Set.new []
end
def outf(format, *args)
@stream.printf(format, *args)
end
def out(*args)
args.each do |arg|
if arg.kind_of?(String)
@stream.write(arg)
elsif arg.kind_of?(Node)
self.render(arg)
elsif arg.kind_of?(Array)
arg.each { |x| self.out(x) }
else
@stream.write(arg)
end
end
end
def render(node)
@node = node
if node.type == :document
self.document(node)
self.out("\n")
if @stringwriter
return @stream.string
end
else
begin
self.send(node.type, node)
rescue NoMethodError
@warnings.add("WARNING: " + node.type.to_s + " not implemented.")
self.out(node.children)
end
end
end
def document(node)
self.out(node.children)
end
def indented_code(node)
self.code_block(node)
end
def fenced_code(node)
self.code_block(node)
end
def setext_header(node)
self.header(node)
end
def atx_header(node)
self.header(node)
end
def reference_def(node)
end
def blocksep
self.out("\n\n")
end
def asblock(&blk)
if @need_blocksep
self.blocksep
end
blk.call
@need_blocksep = true
end
end
class HtmlRenderer < Renderer
def header(node)
asblock do
self.out("<h", node.header_level, ">", node.children,
"</h", node.header_level, ">")
end
end
def paragraph(node)
asblock do
self.out("<p>", node.children, "</p>")
end
end
def hrule(node)
asblock do
self.out("<hr />")
end
end
def code_block(node)
asblock do
self.out("<pre><code>")
self.out(CGI.escapeHTML(node.string_content))
self.out("</code></pre>")
end
end
def emph(node)
self.out("<em>", node.children, "</em>")
end
def strong(node)
self.out("<strong>", node.children, "</strong>")
end
def str(node)
self.out(CGI.escapeHTML(node.string_content))
end
def code(node)
self.out("<code>")
self.out(CGI.escapeHTML(node.string_content))
self.out("</code>")
end
def softbreak(node)
self.out("\n")
end
end
doc = Node.parse_file(STDIN)
renderer = HtmlRenderer.new(STDOUT)
renderer.render(doc)
renderer.warnings.each do |w|
STDERR.write(w)
STDERR.write("\n")
end
# def markdown_to_html(s)
# len = s.bytes.length
# CMark::cmark_markdown_to_html(s, len)
# end
# print markdown_to_html(STDIN.read())
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