Understanding GitHub Code Search syntax

sparse index

The search results would include all documents
containing both the terms sparse and index, in
any order.

To search for an exact string, including
whitespace, you can surround the string in quotes.

"sparse index"

You can use the operators AND, OR, and NOT to
combine search terms.
You can use parentheses to express more
complicated boolean expressions.

(language:ruby OR language:python) AND NOT path:"/tests/"

To narrow down to a specific languages, use the
language: qualifier.

language:ruby OR language:cpp OR language:csharp