How does github do syntax highlighting

For disambiguating between files with common extensions, Linguist applies some heuristics and a statistical classifier. This process can help differentiate between, for example,. Misclassifications can often be solved by either adding a new filename or extension for the language or adding more samples to make the classifier smarter.

Syntax highlighting in GitHub is performed using TextMate-compatible grammars. Every language in languages. This scope name will be used when picking up a grammar for highlighting. Assuming your code is being detected as the right language, in most cases syntax highlighting problems are due to a bug in the language grammar rather than a bug in Linguist.

Find the one corresponding to your code's programming language and submit a bug report upstream. If you can, try to reproduce the highlighting problem in the text editor that the grammar is designed for TextMate, Sublime Text, or Atom and include that information in your bug report. You can also try to fix the bug yourself and submit a pull-request. TextMate's documentation offers a good introduction on how to work with TextMate-compatible grammars. Although they are mostly compatible there might be some differences in syntax and semantics between the two.

You can test grammars using Lightshow. Once the bug has been fixed upstream, we'll pick it up for GitHub in the next release of Linguist. We'd like to ensure Linguist and GitHub.

This often results in someone grasping the opportunity to create a newer and better and more actively maintained grammar, and we'd love to use it and pass on its functionality to our users. For example, a constant variable name can be rendered using constant highlighting throughout the project, not just at the place of its declaration.

Highlighting based on semantic tokens is considered an addition to the TextMate-based syntax highlighting. Semantic highlighting goes on top of the syntax highlighting. And as language servers can take a while to load and analyze a project, semantic token highlighting may appear after a short delay. This article focuses on the TextMate-based tokenization. Semantic tokenization and theming are explained in the Semantic Highlighting Guide.

VS Code uses TextMate grammars as the syntax tokenization engine. Invented for the TextMate editor, they have been adopted by many other editors and IDEs due to large number of language bundles created and maintained by the Open Source community.

You can find a good introduction to TextMate grammars here , and you can take a look at existing TextMate grammars to learn more about how they work.

Tokens are one or more characters that are part of the same program element. Each token is associated with a scope that defines the context of the token. A scope is a dot separated list of identifiers that specify the context of the current token.

Themes map scopes to colors and styles to provide syntax highlighting. TextMate provides list of common scopes that many themes target. In order to have your grammar as broadly supported as possible, try to build on existing scopes rather than defining new ones. Scopes nest so that each token is also associated with a list of parent scopes.

The most specific scope is listed at the top, with more general parent scopes listed below:. Parent scope information is also used for theming. When a theme targets a scope, all tokens with that parent scope will be colorized unless the theme also provides a more specific colorization for their individual scopes.

VS Code supports json TextMate grammars. These are contributed through the grammars contribution point. Each grammar contribution specifies: the identifier of the language the grammar applies to, the top-level scope name for the tokens of the grammar, and the relative path to a grammar file. The example below shows a grammar contribution for a fictional abc language:. Do you think you will? Do you have a favorite code block highlighting or Markdown tip you want to share? Please let me know in the comments or on Twitter with a link to this article and a mention of ardalis.

Steve is an experienced software architect and trainer, focusing on code quality and Domain-Driven Design with. Markdown code fences Markdown is a great language to use to write content in, because it offers built-in styling without the security and other issues that similar markup languages like HTML have.

WriteLine "Hello World! Tags - Browse all tags markdown code writing. Category - Browse all categories Software Development Productivity. About Ardalis Software Architect Steve is an experienced software architect and trainer, focusing on code quality and Domain-Driven Design with. You can find out which keywords are valid in the languages YAML file.

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