python: Add SQL syntax highlighting (#43756)

Jeff Brennan and Piotr Osiewicz created 1 week ago

Release Notes: 

- Added support for SQL syntax highlighting in Python files

## Summary

I am a data engineer who spends a lot of time writing SQL in Python
files using Zed. This PR adds support for SQL syntax highlighting with
common libraries (like pyspark, polars, pandas) and string variables
(prefixed with a `# sql` comment). I referenced
[#37605](https://github.com/zed-industries/zed/pull/37605) for this
implementation to keep the comment prefix consistent.

## Examples
<img width="738" height="990" alt="image"
src="https://github.com/user-attachments/assets/48a859da-c477-490d-be73-ca70d8e47cc9"
/>

---------

Co-authored-by: Piotr Osiewicz <[e-mail]>

Change summary

crates/languages/src/python/injections.scm | 31 ++++++++++++++++++++++++
docs/src/languages/python.md               | 19 ++++++++++++++
2 files changed, 50 insertions(+)

Detailed changes

crates/languages/src/python/injections.scm

@@ -1,3 +1,34 @@
 ((comment) @injection.content
  (#set! injection.language "comment")
 )
+
+; SQL -----------------------------------------------------------------------------
+(
+    [
+        ; function calls
+        (call
+            [
+                (attribute attribute: (identifier) @function_name)
+                (identifier) @function_name
+            ]
+            arguments: (argument_list
+                (comment) @comment
+                (string
+                    (string_content) @injection.content
+                )
+        ))
+
+        ; string variables
+        ((comment) @comment
+            .
+            (expression_statement
+                (assignment
+                    right: (string
+                        (string_content) @injection.content
+                    )
+                )
+        ))
+    ]
+    (#match? @comment "^(#|#\\s+)(?i:sql)\\s*$")
+    (#set! injection.language "sql")
+)

docs/src/languages/python.md

@@ -258,6 +258,25 @@ quote-style = "single"
 
 For more details, refer to the Ruff documentation about [configuration files](https://docs.astral.sh/ruff/configuration/) and [language server settings](https://docs.astral.sh/ruff/editors/settings/), and the [list of options](https://docs.astral.sh/ruff/settings/).
 
+### Embedded Language Highlighting
+
+Zed supports syntax highlighting for code embedded in Python strings by adding a comment with the language name.
+
+```python
+# sql
+query = "SELECT * FROM users"
+
+#sql
+query = """
+    SELECT *
+    FROM users
+"""
+
+result = func( #sql
+    "SELECT * FROM users"
+)
+```
+
 ## Debugging
 
 Zed supports Python debugging through the `debugpy` adapter. You can start with no configuration or define custom launch profiles in `.zed/debug.json`.