comment-patterns/.verb.md

A list of comment-patterns for different languages

# {%= name %}

> {%= description %}

This module contains an extract of the [language-database of `groc`](http://nevir.github.io/groc/languages.html)
with information about how single- and multi-line comments are written in different languages.

## Basic usage

```js
var commentPattern = require('{%= name %}');
var p = commentPattern('filename.js');
```
This will lead to `p` being: 

{%= commentPatterns('filename.js') %}

* **name** is the name of the language
* **nameMatchers** is an array of file extensions of filenames that 
  files in this language usually have.
* **multiLineComment** is an array of patterns for comments that may span multiple lines
  * **start** is the beginning of a comment
  * **middle** is a character of a regex that occurs in front of each comment line
  * **end** marks the end of the comment
* **singleLineComment** is the prefix of comments that go until the end of the line

## Variation (regex)

It is also possible to retrieve a regular expression that matches comments
(up to the next line of code):

```js
var re = commentPattern.regex('filename.js');
```
The result `re` will be:

{%= commentPatterns_regex('filename.js') %}

* **regex** is the actual regular expression. It matches the comments in a string,
  including any empty lines after the comment.
* **cg** are constant values refering to capturing groups of the regex.
  * `match[cg.indent]` contains the spaces that indent comment-start-delimiter.
  * `match[cg.wholeComment]` matches the comment including delimiters.
  * `match[cg.contentStart]` is the first group that captures the contents of the comment
    In this case, there are multiple possible delimiters, so dependending on which 
    delimiter is used, `match[cg.contentStart]` or `match[cg.contentStart + 1]` is
    filled. the others are undefined.
* **middle** contains one pattern for each group after `cg.contentStart` that matches
  the prefix used before comment lines. It can be used to remove this prefix.
  If the middle-prefix for this capturing group is empty (`''`), the pattern is `null`.
* **info** contains additional information for each group after `cg.contentStart`, currently
  this information is only `{ apidocs: true }` if the group is matching an apidoc comment.
* **name** is the language name for debugging purposes.  

## Variation (codeContext)

For API-documentation, it is important to determine the context of the comment (i.e.
the thing that the comment is documenting). Although this does not strictly belong to
the comment itself, this library also has methods to determine the code-context of a comment
These are functions that return a json by matching a single-line of code against a regular expression.

```js
var detector = commentPattern.codeContext("filename.js");
var cc = detector("function abc(param1,param2) {",2);
```

The result in `cc` will be 

{%= codeContext("filename.js","function abc(param1,param2) {",2) %}


This result (for 'JavaScript' is actuall taken from the `parse-code-context` module by Jon Schlinkert.
The method `codeContext` returns a `Detector`

## API-Reference

{%= apidocs("index.js") %}

### The code-context detector

{%= apidocs("lib/detector.js") %}

## The database

The language-specification can be found in the 
`languages`-directory. There is one file
for each language. The actual databases will be
created from these files on `prepublish`.

[The content of language database can be found here](docs/languages.md)

## Contributing

See the [contributing guide](docs/contributing.md)

## Run tests

{%= include("tests") %}

## Related
{%= related(['extract-comments']) %}

## Author
{%= include("author", {github: 'nknapp', twitter: 'knappi79'}) %}

## License
{%= license() %}

***