# Linguist 0.4 README

## 0 Description

Linguist is an extension for Visual Studio 2010 allowing customizable syntax highlighting based on file names. Support for new languages may be easily added using regular expressions to identify the various language elements and language elements may be customized using different fonts, point sizes, colors, and font styles (e.g. bold and italic). The built-in languages include C#, C++, C, Python, Makefiles, patch files, etc.

To install the extension close studio and double-click the `Linguist.vsix` file. To uninstall the extension select the Extension Manager… item from Studio’s Tool menu, select Linguist, and press the Uninstall button. To upgrade the extension uninstall the old version and install the new version.

To check for newer versions of the extension visit github. The software is distributed under the terms of the MIT.X11 licensing agreement (see Licence.txt).

## 1 Operation

When the extension starts up for the first time it will create standard and custom directories inside `%LOCALAPPDATA%\Linguist` or `%USERPROFILE%\AppData\Local\Linguist` (typically this will be something like `C:\Users\<user name>\AppData\Local\Linguist`). The standard directory will contain the built-in language and style files. The custom directory will be empty. When the extension starts up again old or missing files in the standard directory will be added or updated.

Files within the custom directory can be used to define new languages or to override files within the standard directory. Errors are written to a `Log.txt` file in the AppData directory.

Language and style files are written using a simple line-oriented file format. Lines that start with a `#` are comments. Lines with only white space are ignored. Fields start with an identifier, followed by a colon, followed by arbitrary text. Identifiers start with a letter followed by alpha-numeric characters, underscrores, and dashes.

Testing source code changes with the solution is quite simple: make your change, press F5, and a special instance of Studio will launch with the new version of the extension active. Breakpoints may be used normally.

## 2 Style File

The Styles.field file is used to define how to render the various language elements. For example the default style for Makefile targets is:

- Name: target

- ForeColor: DarkGreen

- PointSize: 14

- Bold: true

The following fields can be used within a style file:

- Name: the name of the language element (this is the only required field).

- FontName: the name of a font, e.g. Consolas or Verdana.

- PointSize: the font size, e.g. 12.

- ForeColor: an X11 color name (Red), a hex color (#FF0000), or a decimal color 255,0,0.

- BackColor: an X11 color name (White), a hex color (#FFFFFF), or a decimal color 255,255,255.

- Bold: true if the element should be in bold, and false otherwise.

- Italic: true if the element should be italicized, and false otherwise.

The default element is special and applies to all text within a document. Other elements override any styles used by the default element. Changes to Styles.field files require a restart of Studio to take effect.

## 3 Language Files

Language files are used to define the language elements used by the language. The language elements are matched using globs and the elements are matched using .NET regular expressions. The regexen are compiled using RegexOptions.IgnorePatternWhitespace | RegexOptions.Multiline (so dot does not match new line characters). If parenthesis are used within a regular expression they must be non-grouping (i.e. (?: pattern)).

Here is an example:

- Language: ini

- Globs: *.ini

- Comment: \x23 .* $

- Preprocess: ^ \[ [a-zA-Z] [a-zA-Z0-9_ ]* \]

The following fields can be used within a language file:

- Language: the name of the language, e.g. makefile.

- Globs: space separated list of file name globs where the meta-characters are * and ?, e.g. Makefile *.mk.

- Element: the name of a language element followed by the associated regular expression. The name may be Attribute, Command, Comment, Default, DiffLoc, Emphasis, Header1, Header2, Header3, Header4, Header5, Italic, Keyword, Keyword2, Markup, Method, Monospace, NewText, Number, OldText, Preprocess, Region, ShellVariable, String, Target, Type, or Type2.

Changes to language files in the custom directory take effect while Studio is running (although you may have to scroll to see them).

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