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https://github.com/python/cpython
Revision 9932a22897ef9905161dac7476e6976370e13515 authored by Ivan Levkivskyi on 22 January 2019, 11:18:22 UTC, committed by GitHub on 22 January 2019, 11:18:22 UTC
The majority of this PR is tediously passing `end_lineno` and `end_col_offset` everywhere. Here are non-trivial points:
* It is not possible to reconstruct end positions in AST "on the fly", some information is lost after an AST node is constructed, so we need two more attributes for every AST node `end_lineno` and `end_col_offset`.
* I add end position information to both CST and AST.  Although it may be technically possible to avoid adding end positions to CST, the code becomes more cumbersome and less efficient.
* Since the end position is not known for non-leaf CST nodes while the next token is added, this requires a bit of extra care (see `_PyNode_FinalizeEndPos`). Unless I made some mistake, the algorithm should be linear.
* For statements, I "trim" the end position of suites to not include the terminal newlines and dedent (this seems to be what people would expect), for example in
  ```python
  class C:
      pass

  pass
  ```
  the end line and end column for the class definition is (2, 8).
* For `end_col_offset` I use the common Python convention for indexing, for example for `pass` the `end_col_offset` is 4 (not 3), so that `[0:4]` gives one the source code that corresponds to the node.
* I added a helper function `ast.get_source_segment()`, to get source text segment corresponding to a given AST node. It is also useful for testing.

An (inevitable) downside of this PR is that AST now takes almost 25% more memory. I think however it is probably justified by the benefits.
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Tip revision: 9932a22897ef9905161dac7476e6976370e13515 authored by Ivan Levkivskyi on 22 January 2019, 11:18:22 UTC
bpo-33416: Add end positions to Python AST (GH-11605)
Tip revision: 9932a22
.gitignore
# added for local development
.buildaix/
Modules/python.exp
buildaix/
installp/
.gitignore

# Two-trick pony for OSX and other case insensitive file systems:
# Ignore ./python binary on Unix but still look into ./Python/ directory.
/python
!/Python/
*.cover
*.iml
*.o
*.orig
*.pyc
*.pyd
*.pyo
*.rej
*.swp
*~
*.gc??
*.profclang?
*.profraw
*.dyn
.gdb_history
Doc/build/
Doc/venv/
Doc/.venv/
Doc/env/
Doc/.env/
Include/pydtrace_probes.h
Lib/distutils/command/*.pdb
Lib/lib2to3/*.pickle
Lib/test/data/*
Makefile
Makefile.pre
Misc/python.pc
Misc/python-config.sh
Modules/Setup
Modules/Setup.config
Modules/Setup.local
Modules/config.c
Modules/ld_so_aix
Programs/_freeze_importlib
Programs/_freeze_importlib.exe
Programs/_testembed
Programs/_testembed.exe
PC/python_nt*.h
PC/pythonnt_rc*.h
PC/*/*.exe
PC/*/*.exp
PC/*/*.lib
PC/*/*.bsc
PC/*/*.dll
PC/*/*.pdb
PC/*/*.user
PC/*/*.ncb
PC/*/*.suo
PC/*/Win32-temp-*
PC/*/x64-temp-*
PC/*/amd64
PCbuild/*.user
PCbuild/*.suo
PCbuild/*.*sdf
PCbuild/*-pgi
PCbuild/*-pgo
PCbuild/*.VC.db
PCbuild/*.VC.opendb
PCbuild/.vs/
PCbuild/amd64/
PCbuild/obj/
PCbuild/win32/
.purify
Parser/pgen
Parser/pgen.exe
__pycache__
autom4te.cache
build/
buildno
config.cache
config.log
config.status
config.status.lineno
core
db_home
.hg/
.idea/
ipch/
libpython*.a
libpython*.so*
libpython*.dylib
libpython*.dll
platform
pybuilddir.txt
pyconfig.h
python-config
python-config.py
python.bat
python.exe
python-gdb.py
python.exe-gdb.py
reflog.txt
.svn/
tags
TAGS
.coverage
coverage/
externals/
htmlcov/
Tools/msi/obj
Tools/ssl/amd64
Tools/ssl/win32
.vs/
.vscode/
gmon.out
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