When unparsing a non-empty tuple, the parentheses can be safely
omitted if there aren't any elements that explicitly require them (such as starred expressions).
Unprintable characters such as `\x00` weren't correctly roundtripped
due to not using default string repr when generating docstrings. This
patch correctly encodes all unprintable characters (except `\n` and `\t`, which
are commonly used for formatting, and found unescaped).
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
Co-authored-by: Batuhan Taskaya <isidentical@gmail.com>
* Re-add removed classes Suite, slice, Param, AugLoad and AugStore.
* Add docstrings for dummy classes.
* Add docstrings for attribute aliases.
* Set __module__ to "ast" instead of "_ast".
* Remove the slice type.
* Make Slice a kind of the expr type instead of the slice type.
* Replace ExtSlice(slices) with Tuple(slices, Load()).
* Replace Index(value) with a value itself.
All non-terminal nodes in AST for expressions are now of the expr type.
Allow ast.unparse to detect docstrings in functions, modules and classes and produce
nicely formatted unparsed output for said docstrings.
Co-Authored-By: Pablo Galindo <Pablogsal@gmail.com>
Add ast.unparse() as a function in the ast module that can be used to unparse an
ast.AST object and produce a string with code that would produce an equivalent ast.AST
object when parsed.
Rename compile() feature_version parameter to _feature_version and
convert it to a keyword-only parameter.
Update also test_type_comments to pass feature_version as a tuple.
This adds a `feature_version` flag to `ast.parse()` (documented) and `compile()` (hidden) that allow tweaking the parser to support older versions of the grammar. In particular if `feature_version` is 5 or 6, the hacks for the `async` and `await` keyword from PEP 492 are reinstated. (For 7 or higher, these are unconditionally treated as keywords, but they are still special tokens rather than `NAME` tokens that the parser driver recognizes.)
https://bugs.python.org/issue35975
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.
Remove the docstring attribute of AST types and restore docstring
expression as a first stmt in their body.
Co-authored-by: INADA Naoki <methane@users.noreply.github.com>
* bpo-29463: Add docstring field to some AST nodes.
ClassDef, ModuleDef, FunctionDef, and AsyncFunctionDef has docstring
field for now. It was first statement of there body.
* fix document. thanks travis!
* doc fixes
Issue #26146: Add a new kind of AST node: ast.Constant. It can be used by
external AST optimizers, but the compiler does not emit directly such node.
An optimizer can replace the following AST nodes with ast.Constant:
* ast.NameConstant: None, False, True
* ast.Num: int, float, complex
* ast.Str: str
* ast.Bytes: bytes
* ast.Tuple if items are constants too: tuple
* frozenset
Update code to accept ast.Constant instead of ast.Num and/or ast.Str:
* compiler
* docstrings
* ast.literal_eval()
* Tools/parser/unparse.py
