Draft
Conversation
emcfarlane
force-pushed
the
ed/printer2
branch
from
dbf4d2f to
4422e60
Compare
emcfarlane
force-pushed
the
ed/printer2
branch
from
4422e60 to
c170def
Compare
doriable
reviewed
Feb 3, 2026
Member
doriable
left a comment
doriable
left a comment
There was a problem hiding this comment.
The API looks very reasonable to me, I just had a few nitpicks/discussion points for clarifying a few things. Thank you!
emcfarlane
changed the title
experimental/printer packageexperimental/ast/printer package
emcfarlane
force-pushed
the
ed/printer2
branch
from
ee5138a to
67878ec
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This adds
experimental/ast/printer, an AST printer for protobuf files. It does not yet implement formatting, but uses the dom library to produce correct indentation for synthetic edits. Formatting support will be added later.The printer preserves comments and whitespace using a trivia index. Each comment is classified as either attached (bound to a specific token) or detached (bound to a positional slot between declarations). Attached comments travel with their token when declarations are moved; detached comments stay in place. At print time, the printer zips slot trivia with children within each scope, and looks up attached trivia when emitting individual tokens. This works identically for natural and synthetic tokens (no special-casing needed).