vendor/github.com/russross/blackfriday/README.md
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+Blackfriday [![Build Status](https://travis-ci.org/russross/blackfriday.svg?branch=master)](https://travis-ci.org/russross/blackfriday)
+===========
+
+Blackfriday is a [Markdown][1] processor implemented in [Go][2]. It
+is paranoid about its input (so you can safely feed it user-supplied
+data), it is fast, it supports common extensions (tables, smart
+punctuation substitutions, etc.), and it is safe for all utf-8
+(unicode) input.
+
+HTML output is currently supported, along with Smartypants
+extensions.
+
+It started as a translation from C of [Sundown][3].
+
+
+Installation
+------------
+
+Blackfriday is compatible with any modern Go release. With Go 1.7 and git
+installed:
+
+    go get gopkg.in/russross/blackfriday.v2
+
+will download, compile, and install the package into your `$GOPATH`
+directory hierarchy. Alternatively, you can achieve the same if you
+import it into a project:
+
+    import "gopkg.in/russross/blackfriday.v2"
+
+and `go get` without parameters.
+
+
+Versions
+--------
+
+Currently maintained and recommended version of Blackfriday is `v2`. It's being
+developed on its own branch: https://github.com/russross/blackfriday/v2. You
+should install and import it via [gopkg.in][6] at
+`gopkg.in/russross/blackfriday.v2`.
+
+Version 2 offers a number of improvements over v1:
+
+* Cleaned up API
+* A separate call to [`Parse`][4], which produces an abstract syntax tree for
+  the document
+* Latest bug fixes
+* Flexibility to easily add your own rendering extensions
+
+Potential drawbacks:
+
+* Our benchmarks show v2 to be slightly slower than v1. Currently in the
+  ballpark of around 15%.
+* API breakage. If you can't afford modifying your code to adhere to the new API
+  and don't care too much about the new features, v2 is probably not for you.
+* Several bug fixes are trailing behind and still need to be forward-ported to
+  v2. See issue [#348](https://github.com/russross/blackfriday/issues/348) for
+  tracking.
+
+Usage
+-----
+
+For the most sensible markdown processing, it is as simple as getting your input
+into a byte slice and calling:
+
+```go
+output := blackfriday.Run(input)
+```
+
+Your input will be parsed and the output rendered with a set of most popular
+extensions enabled. If you want the most basic feature set, corresponding with
+the bare Markdown specification, use:
+
+```go
+output := blackfriday.Run(input, blackfriday.WithNoExtensions())
+```
+
+### Sanitize untrusted content
+
+Blackfriday itself does nothing to protect against malicious content. If you are
+dealing with user-supplied markdown, we recommend running Blackfriday's output
+through HTML sanitizer such as [Bluemonday][5].
+
+Here's an example of simple usage of Blackfriday together with Bluemonday:
+
+```go
+import (
+    "github.com/microcosm-cc/bluemonday"
+    "github.com/russross/blackfriday"
+)
+
+// ...
+unsafe := blackfriday.Run(input)
+html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
+```
+
+### Custom options
+
+If you want to customize the set of options, use `blackfriday.WithExtensions`,
+`blackfriday.WithRenderer` and `blackfriday.WithRefOverride`.
+
+You can also check out `blackfriday-tool` for a more complete example
+of how to use it. Download and install it using:
+
+    go get github.com/russross/blackfriday-tool
+
+This is a simple command-line tool that allows you to process a
+markdown file using a standalone program.  You can also browse the
+source directly on github if you are just looking for some example
+code:
+
+* <http://github.com/russross/blackfriday-tool>
+
+Note that if you have not already done so, installing
+`blackfriday-tool` will be sufficient to download and install
+blackfriday in addition to the tool itself. The tool binary will be
+installed in `$GOPATH/bin`.  This is a statically-linked binary that
+can be copied to wherever you need it without worrying about
+dependencies and library versions.
+
+
+Features
+--------
+
+All features of Sundown are supported, including:
+
+*   **Compatibility**. The Markdown v1.0.3 test suite passes with
+    the `--tidy` option.  Without `--tidy`, the differences are
+    mostly in whitespace and entity escaping, where blackfriday is
+    more consistent and cleaner.
+
+*   **Common extensions**, including table support, fenced code
+    blocks, autolinks, strikethroughs, non-strict emphasis, etc.
+
+*   **Safety**. Blackfriday is paranoid when parsing, making it safe
+    to feed untrusted user input without fear of bad things
+    happening. The test suite stress tests this and there are no
+    known inputs that make it crash.  If you find one, please let me
+    know and send me the input that does it.
+
+    NOTE: "safety" in this context means *runtime safety only*. In order to
+    protect yourself against JavaScript injection in untrusted content, see
+    [this example](https://github.com/russross/blackfriday#sanitize-untrusted-content).
+
+*   **Fast processing**. It is fast enough to render on-demand in
+    most web applications without having to cache the output.
+
+*   **Thread safety**. You can run multiple parsers in different
+    goroutines without ill effect. There is no dependence on global
+    shared state.
+
+*   **Minimal dependencies**. Blackfriday only depends on standard
+    library packages in Go. The source code is pretty
+    self-contained, so it is easy to add to any project, including
+    Google App Engine projects.
+
+*   **Standards compliant**. Output successfully validates using the
+    W3C validation tool for HTML 4.01 and XHTML 1.0 Transitional.
+
+
+Extensions
+----------
+
+In addition to the standard markdown syntax, this package
+implements the following extensions:
+
+*   **Intra-word emphasis supression**. The `_` character is
+    commonly used inside words when discussing code, so having
+    markdown interpret it as an emphasis command is usually the
+    wrong thing. Blackfriday lets you treat all emphasis markers as
+    normal characters when they occur inside a word.
+
+*   **Tables**. Tables can be created by drawing them in the input
+    using a simple syntax:
+
+    ```
+    Name    | Age
+    --------|------
+    Bob     | 27
+    Alice   | 23
+    ```
+
+*   **Fenced code blocks**. In addition to the normal 4-space
+    indentation to mark code blocks, you can explicitly mark them
+    and supply a language (to make syntax highlighting simple). Just
+    mark it like this:
+
+        ```go
+        func getTrue() bool {
+            return true
+        }
+        ```
+
+    You can use 3 or more backticks to mark the beginning of the
+    block, and the same number to mark the end of the block.
+
+*   **Definition lists**. A simple definition list is made of a single-line
+    term followed by a colon and the definition for that term.
+
+        Cat
+        : Fluffy animal everyone likes
+        
+        Internet
+        : Vector of transmission for pictures of cats
+
+    Terms must be separated from the previous definition by a blank line.
+
+*   **Footnotes**. A marker in the text that will become a superscript number;
+    a footnote definition that will be placed in a list of footnotes at the
+    end of the document. A footnote looks like this:
+
+        This is a footnote.[^1]
+        
+        [^1]: the footnote text.
+
+*   **Autolinking**. Blackfriday can find URLs that have not been
+    explicitly marked as links and turn them into links.
+
+*   **Strikethrough**. Use two tildes (`~~`) to mark text that
+    should be crossed out.
+
+*   **Hard line breaks**. With this extension enabled newlines in the input
+    translate into line breaks in the output. This extension is off by default.
+
+*   **Smart quotes**. Smartypants-style punctuation substitution is
+    supported, turning normal double- and single-quote marks into
+    curly quotes, etc.
+
+*   **LaTeX-style dash parsing** is an additional option, where `--`
+    is translated into `&ndash;`, and `---` is translated into
+    `&mdash;`. This differs from most smartypants processors, which
+    turn a single hyphen into an ndash and a double hyphen into an
+    mdash.
+
+*   **Smart fractions**, where anything that looks like a fraction
+    is translated into suitable HTML (instead of just a few special
+    cases like most smartypant processors). For example, `4/5`
+    becomes `<sup>4</sup>&frasl;<sub>5</sub>`, which renders as
+    <sup>4</sup>&frasl;<sub>5</sub>.
+
+
+Other renderers
+---------------
+
+Blackfriday is structured to allow alternative rendering engines. Here
+are a few of note:
+
+*   [github_flavored_markdown](https://godoc.org/github.com/shurcooL/github_flavored_markdown):
+    provides a GitHub Flavored Markdown renderer with fenced code block
+    highlighting, clickable heading anchor links.
+
+    It's not customizable, and its goal is to produce HTML output
+    equivalent to the [GitHub Markdown API endpoint](https://developer.github.com/v3/markdown/#render-a-markdown-document-in-raw-mode),
+    except the rendering is performed locally.
+
+*   [markdownfmt](https://github.com/shurcooL/markdownfmt): like gofmt,
+    but for markdown.
+
+*   [LaTeX output](https://bitbucket.org/ambrevar/blackfriday-latex):
+    renders output as LaTeX.
+
+
+Todo
+----
+
+*   More unit testing
+*   Improve unicode support. It does not understand all unicode
+    rules (about what constitutes a letter, a punctuation symbol,
+    etc.), so it may fail to detect word boundaries correctly in
+    some instances. It is safe on all utf-8 input.
+
+
+License
+-------
+
+[Blackfriday is distributed under the Simplified BSD License](LICENSE.txt)
+
+
+   [1]: https://daringfireball.net/projects/markdown/ "Markdown"
+   [2]: https://golang.org/ "Go Language"
+   [3]: https://github.com/vmg/sundown "Sundown"
+   [4]: https://godoc.org/gopkg.in/russross/blackfriday.v2#Parse "Parse func"
+   [5]: https://github.com/microcosm-cc/bluemonday "Bluemonday"
+   [6]: https://labix.org/gopkg.in "gopkg.in"