[New-bugs-announce] [issue15517] Minor trimming for ASDL parser

[Taihyun Hwang]

New submission from Taihyun Hwang:

Attached patch enables ASDL parser to construct fields in the right order.

It resolves the issue below in Parser/asdl.py
# XXX can't I just construct things in the right order?

We can safely use left-recursive grammar since Parser/spark.py implements Earley parser.


The patch doesn't affect Python-ast.[ch] as expected.

$ make Include/Python-ast.h Python/Python-ast.c
$ diff -s ~/test/Python-ast.h Include/Python-ast.h
Files /home/xenosoz/test/Python-ast.h and Include/Python-ast.h are identical
$ diff -s ~/test/Python-ast.c Python/Python-ast.c
Files /home/xenosoz/test/Python-ast.c and Python/Python-ast.c are identical


Time consumption before/after the patch:
-- before patch --
time make Include/Python-ast.h
real    0m0.578s \ user    0m0.500s \ sys     0m0.060s

time make Python/Python-ast.c
real    0m0.687s \ user    0m0.620s \ sys     0m0.050s

-- after patch --
$ time make Include/Python-ast.h
real    0m0.588s \ user    0m0.510s \ sys     0m0.060s

$ time make Python/Python-ast.c
real    0m0.677s \ user    0m0.630s \ sys     0m0.030s


It touches:
Misc/ACKS
Parser/asdl.py

----------
components: Interpreter Core
files: asdl1.patch
keywords: patch
messages: 167056
nosy: taihyun.hwang
priority: normal
severity: normal
status: open
title: Minor trimming for ASDL parser
type: enhancement
versions: Python 3.3
Added file: http://bugs.python.org/file26631/asdl1.patch

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue15517>
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