Search Subexpressions

This page provides docs about using Search Subexpressions in Sourcegraph's Code Search.

Search subexpressions combine groups of filters like repo: and operators like or. Compared to basic examples, search subexpressions allow more sophisticated queries.

Here are examples of how they can help you:

1. Noncompliant spelling where case-sensitivity differs depending on the word.

 repo:sourcegraph ((Github case:yes) or (organisation case:no))

The about code finds places to change the spelling of Github to GitHub (case-sensitivity matters) or change the spelling of organisation to organization (case-sensitivity does not matter).

2. Search for either a file name or file contents scoped to the same repository.

repo:sourcegraph -file:html (file:router or newRouter)

The above code finds both files containing the word router or file contents matching newRouter in the same repository, while excluding html files. Useful when exploring files or code that interact with a general term like router.

3. Scope file content searches to particular files or repositories

 repo:sourcegraph
 (
  (file:schema.graphql hover(...))
  or
  (file:codeintel.go (Line or Character))
 )
 patterntype:structural

Combine matches of hover(...) in the schema.graphql file and matches of Line or Character in the codeintel.go file in the same repository. Useful for crafting queries that precisely match related fragments of a codebase to capture context and e.g., share with coworkers.

4. Search across multiple repositories at multiple revisions.

 (
   repo:^github\.com/sourcegraph/[email protected]:v3.22.1
   or
   repo:^github\.com/sourcegraph/[email protected]:3.22.1
 )
 file:CHANGELOG campaigns

Finds the word campaigns in CHANGELOG files for two repositories, sourcegraph/sourcegraph or sourcegraph/src-cli, at specific revisions. Useful for searching across a larger scope of repositories at particular revisions.

General tips for crafting queries with subexpressions

Fully parenthesize subexpressions

It's best practice to parenthesize queries to avoid confusion. For example, there are multiple ways to group the query, which is not fully parenthesized:

repo:sourcegraph (Github case:yes) or (organisation case:no)

It could mean either of these:

(repo:sourcegraph (Github case:yes)) or (organisation case:no)

repo:sourcegraph ((Github case:yes) or (organisation case:no))

When parentheses are absent, we use the convention that operators divide sequences of terms that should be grouped together. That is: file:main.c char c or (int i and int j) generally means (file:main.c char c) or (int i and int j).

This convention means we would pick the following meaning of the original query, but it may not be what you intended:

(repo:sourcegraph (Github case:yes)) or (organisation case:no)

Fully parenthesizing subexpressions makes it clear what the intent is, so that you can avoid relying on conventions that may not interpret the query the way you intended.

Subexpression expansion

If you're unsure whether a subexpression is valid, it may be useful to think in terms of how a subexpression expands to multiple independent queries. Expansion relies on a distributive property over or-expressions. For example:

repo:sourcegraph ((Github case:yes) or (organisation case:no))

This is equivalent to expanding the query by putting repo:sourcegraph inside each subexpression:

(repo:sourcegraph Github case:yes) or (repo:sourcegraph organisation case:no)

This query is valid because each side of the or operator is a valid query. On the other hand, the following query is invalid:

repo:sourcegraph case:yes (Github or (case:no organisation))

Because after expanding it is equivalent to:

(repo:sourcegraph case:yes Github) or (repo:sourcegraph case:yes case:no organisation)

After expanding, the right-hand side contains both case:yes and case:no. Since this subpart of the query is invalid, the original query is also invalid.