Skip to content

gh-153568: Reduce parser allocations #157374

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
pablogsal wants to merge 10 commits into
base: main
Choose a base branch
from
Open

gh-153568: Reduce parser allocations #157374

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
e8f8854
gh-153568: Allocate parser tokens in blocks
pablogsal Sep 12, 2026
a66ca87
gh-153568: Avoid copying fixed parser token text
pablogsal Sep 12, 2026
d5cc533
gh-153568: Allocate the parser identifier cache on first use
pablogsal Sep 12, 2026
472faa2
gh-153568: Reuse the tokenizer newline buffer
pablogsal Sep 12, 2026
7c9f1cd
gh-153568: Clear memo filters before the parser error pass
pablogsal Sep 12, 2026
c669a32
gh-153568: Reuse parsed name nodes during backtracking
pablogsal Sep 12, 2026
e2e3e7d
gh-153568: Reuse parsed numbers during backtracking
pablogsal Sep 12, 2026
5252627
gh-153568: Explain parser allocation and buffer invariants
pablogsal Sep 14, 2026
ac85f97
gh-153568: Simplify parser identifier and buffer handling
pablogsal Sep 14, 2026
dd5b683
gh-153568: Keep NOTEQUAL spelling in token text
pablogsal Sep 14, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions Grammar/python.gram
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1181,8 +1181,12 @@ invalid_arguments:
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
| a=args ',' args { _PyPegen_arguments_parsing_error(p, a) }
invalid_kwarg:
| a[Token*]=('True'|'False'|'None') b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to %s", PyBytes_AS_STRING(a->bytes)) }
| a='True' b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to True") }
| a='False' b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to False") }
| a='None' b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to None") }
| a=NAME b='=' expression for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
| !(NAME '=') a=expression b='=' {
Expand Down
1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Core_and_Builtins/2026-09-12-12-00-00.gh-issue-153568.parser.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Reduce temporary allocations while parsing Python source.
Loading
Loading