Commit Graph

272 Commits

Author SHA1 Message Date
Pablo Galindo Salgado 7a1d932528
bpo-45450: Improve syntax error for parenthesized arguments (GH-28906) 2021-11-20 18:27:40 +00:00
Pablo Galindo Salgado 546cefcda7
bpo-45727: Make the syntax error for missing comma more consistent (GH-29427) 2021-11-19 23:11:57 +00:00
Carl Friedrich Bolz-Tereick 2819e98d10
bpo-45764: improve error message when missing '(' after 'def' (GH-29484)
to achieve this, change the grammar to expect the '(' token after 'def' NAME.

Automerge-Triggered-By: GH:pablogsal
2021-11-09 06:03:32 -08:00
Pablo Galindo Salgado e2d65630f3
bpo-45716: Improve the error message when using True/False/None as keywords in a call (GH-29413) 2021-11-05 13:54:55 +00:00
wim glenn 762173c670
bpo-44257: fix "assigment_expr" typo + regenerate the grammar, and remove unused imports (GH-29393)
Co-authored-by: Wim Glenn <wglenn@jumptrading.com>
2021-11-03 20:57:40 +00:00
Pablo Galindo Salgado e5f13ce5b4
bpo-43914: Correctly highlight SyntaxError exceptions for invalid generator expression in function calls (GH-28576) 2021-09-27 14:37:43 +01:00
Pablo Galindo Salgado b2f68b1900
bpo-44947: Refine the syntax error for trailing commas in import statements (GH-27814) 2021-08-18 22:09:21 +02:00
Pablo Galindo Salgado f5cbea6b1b
bpo-44838: Refine the custom syntax errors for invalid 'if' expressions (GH-27615) 2021-08-05 18:28:57 +01:00
Miguel Brito 28b6dc9dd5
bpo-44792: Improve syntax errors for if expressions (GH-27506) 2021-08-02 18:11:37 +01:00
Pablo Galindo Salgado 208a7e957b
bpo-34013: Don't consider a grouped expression when reporting legacy print syntax errors (GH-27521) 2021-08-01 02:10:50 +01:00
Pablo Galindo Salgado 302cf35505
Divide the grammar into sections to improve readability (GH-27502) 2021-07-31 13:04:37 +01:00
Pablo Galindo Salgado ecc3c8e421
bpo-34013: Move the Python 2 hints from the exception constructor to the parser (GH-27392) 2021-07-27 21:30:32 +01:00
Pablo Galindo Salgado 6948964ecf
bpo-34013: Generalize the invalid legacy statement error message (GH-27389) 2021-07-27 17:19:22 +01:00
Pablo Galindo Salgado a283ef116b
Remove unnecessary 'invalid_primary' rule in the parser (GH-27186) 2021-07-16 13:20:09 +01:00
Pablo Galindo 0acc258fe6
bpo-44456: Improve the syntax error when mixing keyword and positional patterns (GH-26793) 2021-06-24 16:09:57 +01:00
Pablo Galindo 05073036dc
bpo-44368: Improve syntax errors with invalid as pattern targets (GH-26632) 2021-06-10 23:50:32 +01:00
Lysandros Nikolaou e7b4644607
bpo-44385: Remove unused grammar rules (GH-26655)
Automerge-Triggered-By: GH:lysnikolaou
2021-06-10 15:05:06 -07:00
Pablo Galindo b250f89bb7
bpo-44305: Improve syntax error for try blocks without except or finally (GH-26523) 2021-06-03 23:52:12 +01:00
Pablo Galindo c878a97968
bpo-44180: Fix edge cases in invalid assigment rules in the parser (GH-26283)
The invalid assignment rules are very delicate since the parser can
easily raise an invalid assignment when a keyword argument is provided.
As they are very deep into the grammar tree, is very difficult to
specify in which contexts these rules can be used and in which don't.
For that, we need to use a different version of the rule that doesn't do
error checking in those situations where we don't want the rule to raise
(keyword arguments and generator expressions).

We also need to check if we are in left-recursive rule, as those can try
to eagerly advance the parser even if the parse will fail at the end of
the expression. Failing to do this allows the parser to start parsing a
call as a tuple and incorrectly identify a keyword argument as an
invalid assignment, before it realizes that it was not a tuple after all.
2021-05-21 18:34:54 +01:00
Pablo Galindo 33c0c90dea
bpo-44168: Fix error message in the parser for keyword arguments for invalid expressions (GH-26210) 2021-05-19 19:03:04 +01:00
Pablo Galindo 6692dc1ca9
bpo-43149: Correct the syntax error message for multiple exception types (GH-25996)
Automerge-Triggered-By: GH:pablogsal
2021-05-08 11:24:41 -07:00
Brandt Bucher dbe60ee09d
bpo-43892: Validate the first term of complex literal value patterns (GH-25735) 2021-04-29 17:19:28 -07:00
Nick Coghlan 1e7b858575
bpo-43892: Make match patterns explicit in the AST (GH-25585)
Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>
2021-04-28 22:58:44 -07:00
Pablo Galindo a77aac4fca
bpo-43914: Highlight invalid ranges in SyntaxErrors (#25525)
To improve the user experience understanding what part of the error messages associated with SyntaxErrors is wrong, we can highlight the whole error range and not only place the caret at the first character. In this way:

>>> foo(x, z for z in range(10), t, w)
  File "<stdin>", line 1
    foo(x, z for z in range(10), t, w)
           ^
SyntaxError: Generator expression must be parenthesized

becomes

>>> foo(x, z for z in range(10), t, w)
  File "<stdin>", line 1
    foo(x, z for z in range(10), t, w)
           ^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized
2021-04-23 14:27:05 +01:00
Pablo Galindo 56c95dfe27
bpo-43859: Improve the error message for IndentationError exceptions (GH-25431) 2021-04-21 15:28:21 +01:00
Pablo Galindo b5b98bd8f8
bpo-43823: Fix location of one of the errors for invalid dictionary literals (GH-25427) 2021-04-16 00:45:42 +01:00
Pablo Galindo b280248be8
bpo-43822: Improve syntax errors for missing commas (GH-25377) 2021-04-15 21:38:45 +01:00
Pablo Galindo da74350174
bpo-43823: Improve syntax errors for invalid dictionary literals (GH-25378) 2021-04-15 14:06:39 +01:00
Pablo Galindo 30ed93bfec
bpo-43797: Handle correctly invalid assignments inside function calls and generators (GH-25390) 2021-04-13 17:51:21 +01:00
Pablo Galindo d9151cb453
Ensure that early = are not matched by the parser as invalid comparisons (GH-25375) 2021-04-13 02:32:33 +01:00
Pablo Galindo b86ed8e3bb
bpo-43797: Improve syntax error for invalid comparisons (#25317)
* bpo-43797: Improve syntax error for invalid comparisons

* Update Lib/test/test_fstring.py

Co-authored-by: Guido van Rossum <gvanrossum@gmail.com>

* Apply review comments

* can't -> cannot

Co-authored-by: Guido van Rossum <gvanrossum@gmail.com>
2021-04-12 16:59:30 +01:00
Matthew Suozzo 75a06f067b
bpo-43798: Add source location attributes to alias (GH-25324)
* Add source location attributes to alias.
* Move alias star construction to pegen helper.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
2021-04-10 22:56:28 +02:00
Victor Stinner d27f8d2e07
bpo-43244: Rename pycore_ast.h functions to _PyAST_xxx() (GH-25252)
Rename AST functions of pycore_ast.h to use the "_PyAST_" prefix.
Remove macros creating aliases without prefix. For example, Module()
becomes _PyAST_Module(). Update Grammar/python.gram to use
_PyAST_xxx() functions.
2021-04-07 21:34:22 +02:00
Pablo Galindo 8efad61963
bpo-41064: Improve syntax error for invalid usage of '**' in f-strings (GH-25006) 2021-03-24 19:34:17 +00:00
Pablo Galindo 08fb8ac99a
bpo-42128: Add 'missing :' syntax error message to match statements (GH-24733) 2021-03-18 01:03:11 +00:00
Brandt Bucher 145bf269df
bpo-42128: Structural Pattern Matching (PEP 634) (GH-22917)
Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Talin <viridia@gmail.com>
Co-authored-by: Pablo Galindo <pablogsal@gmail.com>
2021-02-26 14:51:55 -08:00
Pablo Galindo 206cbdab16
bpo-43149: Improve error message for exception group without parentheses (GH-24467) 2021-02-07 18:42:21 +00:00
Pablo Galindo d4e6ed7e5f
bpo-43121: Fix incorrect SyntaxError message for missing comma (GH-24436) 2021-02-03 23:29:26 +00:00
Pablo Galindo 58fb156edd
bpo-42997: Improve error message for missing : before suites (GH-24292)
* Add to the peg generator a new directive ('&&') that allows to expect
  a token and hard fail the parsing if the token is not found. This
  allows to quickly emmit syntax errors for missing tokens.

* Use the new grammar element to hard-fail if the ':' is missing before
  suites.
2021-02-02 19:54:22 +00:00
Pablo Galindo 835f14ff8e
bpo-43017: Improve error message for unparenthesised tuples in comprehensions (GH24314) 2021-01-31 22:52:56 +00:00
Lysandros Nikolaou 07dcd86cee
bpo-42860: Remove type error from grammar (GH-24156)
This is only there so that alternative implementations written in statically-typed languages can use this grammar without
having type errors in the way.

Automerge-Triggered-By: GH:lysnikolaou
2021-01-07 14:31:25 -08:00
Lysandros Nikolaou 2ea320dddd
bpo-40631: Disallow single parenthesized star target (GH-24027) 2021-01-03 01:14:21 +02:00
Pablo Galindo 43c4fb6c90
bpo-30858: Improve error location for expressions with assignments (GH-23753)
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
2020-12-13 16:46:48 +00:00
Pablo Galindo 9bdc40ee3e
Refactor the grammar to match the language specification docs (GH-23574) 2020-11-30 19:42:38 +00:00
Pablo Galindo b0aba1fcdc
bpo-42381: Allow walrus in set literals and set comprehensions (GH-23332)
Currently walruses are not allowerd in set literals and set comprehensions:

>>> {y := 4, 4**2, 3**3}
  File "<stdin>", line 1
    {y := 4, 4**2, 3**3}
       ^
SyntaxError: invalid syntax

but they should be allowed as well per PEP 572
2020-11-17 01:17:12 +00:00
Lysandros Nikolaou cae60187cf
bpo-42316: Allow unparenthesized walrus operator in indexes (GH-23317) 2020-11-17 01:09:35 +02:00
Lysandros Nikolaou cb3e5ed071
bpo-42374: Allow unparenthesized walrus in genexps (GH-23319)
This fixes a regression that was introduced by the new parser.

Automerge-Triggered-By: GH:lysnikolaou
2020-11-16 15:08:35 -08:00
Pablo Galindo 06f8c3328d
bpo-42214: Fix check for NOTEQUAL token in the PEG parser for the barry_as_flufl rule (GH-23048) 2020-10-30 23:48:42 +00:00
Lysandros Nikolaou 15acc4eaba
bpo-41659: Disallow curly brace directly after primary (GH-22996) 2020-10-27 20:54:20 +02:00
Lysandros Nikolaou bca7014032
bpo-42123: Run the parser two times and only enable invalid rules on the second run (GH-22111)
* Implement running the parser a second time for the errors messages

The first parser run is only responsible for detecting whether
there is a `SyntaxError` or not. If there isn't the AST gets returned.
Otherwise, the parser is run a second time with all the `invalid_*`
rules enabled so that all the customized error messages get produced.
2020-10-27 00:42:04 +02:00
Lysandros Nikolaou 2e5ca9e3f6
bpo-41746: Cast to typed seqs in CHECK macros to avoid type erasure (GH-22864) 2020-10-21 22:53:14 +03:00
Batuhan Taskaya 48f305fd12
bpo-41979: Accept star-unpacking on with-item targets (GH-22611)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
2020-10-09 10:56:48 +01:00
Pablo Galindo a5634c4067
bpo-41746: Add type information to asdl_seq objects (GH-22223)
* Add new capability to the PEG parser to type variable assignments. For instance:
```
       | a[asdl_stmt_seq*]=';'.small_stmt+ [';'] NEWLINE { a }
```

* Add new sequence types from the asdl definition (automatically generated)
* Make `asdl_seq` type a generic aliasing pointer type.
* Create a new `asdl_generic_seq` for the generic case using `void*`.
* The old `asdl_seq_GET`/`ast_seq_SET` macros now are typed.
* New `asdl_seq_GET_UNTYPED`/`ast_seq_SET_UNTYPED` macros for dealing with generic sequences.
* Changes all possible `asdl_seq` types to use specific versions everywhere.
2020-09-16 19:42:00 +01:00
Pablo Galindo 315a61f7a9
bpo-41697: Correctly handle KeywordOrStarred when parsing arguments in the parser (GH-22077) 2020-09-03 15:29:32 +01:00
Pablo Galindo 4a97b1517a
bpo-41690: Use a loop to collect args in the parser instead of recursion (GH-22053)
This program can segfault the parser by stack overflow:

```
import ast

code = "f(" + ",".join(['a' for _ in range(100000)]) + ")"
print("Ready!")
ast.parse(code)
```

the reason is that the rule for arguments has a simple recursion when collecting args:

args[expr_ty]:
    [...]
    | a=named_expression b=[',' c=args { c }] {
        [...] }
2020-09-02 17:44:19 +01:00
Pablo Galindo 72cabb2aa6
bpo-40939: Use the new grammar for the grammar specification documentation (GH-19969)
(We censor the heck out of actions and some other stuff using a custom "highlighter".)

Co-authored-by: Guido van Rossum <guido@python.org>
2020-07-27 11:20:36 -07:00
Guido van Rossum 508ed2d912
Delete remaining references to Grammar/Grammar from docs (#21624)
(Ironically, the file itself remains, see https://github.com/we-like-parsers/cpython/issues/135.)
2020-07-26 08:27:52 -07:00
Batuhan Taskaya c8f29ad986
bpo-40769: Allow extra surrounding parentheses for invalid annotated assignment rule (GH-20387) 2020-06-27 19:33:08 +01:00
Lysandros Nikolaou 4b85e60601
bpo-41119: Output correct error message for list/tuple followed by colon (GH-21160) 2020-06-26 00:22:36 +01:00
Lysandros Nikolaou 6c4e0bd974
bpo-41060: Avoid SEGFAULT when calling GET_INVALID_TARGET in the grammar (GH-21020)
`GET_INVALID_TARGET` might unexpectedly return `NULL`, which if not
caught will cause a SEGFAULT. Therefore, this commit introduces a new
inline function `RAISE_SYNTAX_ERROR_INVALID_TARGET` that always
checks for `GET_INVALID_TARGET` returning NULL and can be used in
the grammar, replacing the long C ternary operation used till now.
2020-06-21 03:18:01 +01:00
Lysandros Nikolaou 01ece63d42
bpo-40334: Produce better error messages on invalid targets (GH-20106)
The following error messages get produced:
- `cannot delete ...` for invalid `del` targets
- `... is an illegal 'for' target` for invalid targets in for
  statements
- `... is an illegal 'with' target` for invalid targets in
  with statements

Additionally, a few `cut`s were added in various places before the
invocation of the `invalid_*` rule, in order to speed things
up.

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
2020-06-19 00:10:43 +01:00
Pablo Galindo b4282dd150
Remove unnecessary grammar decorations and change header (GH-20819) 2020-06-12 00:51:44 +01:00
Lysandros Nikolaou bcd7deed91
bpo-40939: Remove PEG parser easter egg (__new_parser__) (#20802)
It no longer serves a purpose (there's only one parser) and having "new" in any name will eventually look odd. Also, it impinges on a potential sub-namespace, `__new_...__`.
2020-06-11 09:09:21 -07:00
Pablo Galindo c6483c9896
Raise specialised syntax error for invalid lambda parameters (GH-20776) 2020-06-10 14:07:06 +01:00
Pablo Galindo 9f495908c5
bpo-40903: Handle multiple '=' in invalid assignment rules in the PEG parser (GH-20697)
Automerge-Triggered-By: @pablogsal
2020-06-07 18:57:00 -07:00
Lysandros Nikolaou ae14583302
bpo-40334: Produce better error messages for non-parenthesized genexps (GH-20153)
The error message, generated for a non-parenthesized generator expression
in function calls, was still the generic `invalid syntax`, when the generator expression wasn't appearing as the first argument in the call. With this patch, even on input like `f(a, b, c for c in d, e)`, the correct error message gets produced.
2020-05-22 01:56:52 +01:00
Batuhan Taskaya b8a65ec1d3
bpo-40715: Reject dict unpacking on dict comprehensions (GH-20292)
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
Co-authored-by: Pablo Galindo <pablogsal@gmail.com>
2020-05-21 23:39:56 +01:00
Batuhan Taskaya 72e0aa2fd2
bpo-40176: Improve error messages for trailing comma on from import (GH-20294) 2020-05-21 21:41:58 +01:00
Lysandros Nikolaou 75b863aa97
bpo-40334: Reproduce error message for type comments on bare '*' in the new parser (GH-20151) 2020-05-18 20:14:47 +01:00
Pablo Galindo 16ab07063c
bpo-40334: Correctly identify invalid target in assignment errors (GH-20076)
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
2020-05-15 02:04:52 +01:00
Lysandros Nikolaou ce21cfca7b
bpo-40618: Disallow invalid targets in augassign and except clauses (GH-20083)
This commit fixes the new parser to disallow invalid targets in the
following scenarios:
- Augmented assignments must only accept a single target (Name,
  Attribute or Subscript), but no tuples or lists.
- `except` clauses should only accept a single `Name` as a target.

Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
2020-05-14 21:13:50 +01:00
Lysandros Nikolaou a15c9b3a05
bpo-40334: Always show the caret on SyntaxErrors (GH-20050)
This commit fixes SyntaxError locations when the caret is not displayed,
by doing the following:

- `col_number` always gets set to the location of the offending
  node/expr. When no caret is to be displayed, this gets achieved
  by setting the object holding the error line to None.

- Introduce a new function `_PyPegen_raise_error_known_location`,
  which can be called, when an arbitrary `lineno`/`col_offset`
  needs to be passed. This function then gets used in the grammar
  (through some new macros and inline functions) so that SyntaxError
  locations of the new parser match that of the old.
2020-05-13 20:36:27 +01:00
Shantanu 27c0d9b54a
bpo-40334: produce specialized errors for invalid del targets (GH-19911) 2020-05-11 14:53:58 -07:00
Lysandros Nikolaou 4638c64295
bpo-40334: Error message for invalid default args in function call (GH-19973)
When parsing something like `f(g()=2)`, where the name of a default arg
is not a NAME, but an arbitrary expression, a specialised error message
is emitted.
2020-05-07 11:44:06 +01:00
Pablo Galindo 99db2a1db7
bpo-40334: Allow trailing comma in parenthesised context managers (GH-19964) 2020-05-06 22:54:34 +01:00
Lysandros Nikolaou 999ec9ab6a
bpo-40334: Add type to the assignment rule in the grammar file (GH-19963) 2020-05-06 19:11:04 +01:00
Lysandros Nikolaou e10e7c771b
bpo-40334: Spacialized error message for invalid args after bare '*' (GH-19865)
When parsing things like `def f(*): pass` the old parser used to output `SyntaxError: named arguments must follow bare *`, which the new parser wasn't able to do.
2020-05-04 11:58:31 +01:00
Shantanu 603d354626
bpo-40493: fix function type comment parsing (GH-19894)
The grammar for func_type_input rejected things like `(*t1) ->t2`. This fixes that.

Automerge-Triggered-By: @gvanrossum
2020-05-03 22:08:14 -07:00
Guido van Rossum 3941d9700b
bpo-40334: Refactor lambda_parameters similar to parameters (GH-19830) 2020-05-01 17:42:03 +01:00
Pablo Galindo d955241469
bpo-40334: Correct return value of func_type_comment (GH-19833) 2020-05-01 08:32:09 -07:00
Batuhan Taskaya 76c1b4d5c5
bpo-40334: Improve column offsets for thrown syntax errors by Pegen (GH-19782) 2020-05-01 14:13:43 +01:00
Lysandros Nikolaou 3e0a6f37df
bpo-40334: Add support for feature_version in new PEG parser (GH-19827)
`ast.parse` and `compile` support a `feature_version` parameter that
tells the parser to parse the input string, as if it were written in
an older Python version.
The `feature_version` is propagated to the tokenizer, which uses it
to handle the three different stages of support for `async` and
`await`. Additionally, it disallows the following at parser level:
- The '@' operator in < 3.5
- Async functions in < 3.5
- Async comprehensions in < 3.6
- Underscores in numeric literals in < 3.6
- Await expression in < 3.5
- Variable annotations in < 3.6
- Async for-loops in < 3.5
- Async with-statements in < 3.5
- F-strings in < 3.6

Closes we-like-parsers/cpython#124.
2020-04-30 20:27:52 -07:00
Guido van Rossum c001c09e90
bpo-40334: Support type comments (GH-19780)
This implements full support for # type: <type> comments, # type: ignore <stuff> comments, and the func_type parsing mode for ast.parse() and compile().

Closes https://github.com/we-like-parsers/cpython/issues/95.

(For now, you need to use the master branch of mypy, since another issue unique to 3.9 had to be fixed there, and there's no mypy release yet.)

The only thing missing is `feature_version=N`, which is being tracked in https://github.com/we-like-parsers/cpython/issues/124.
2020-04-30 12:12:19 -07:00
Pablo Galindo 2b74c835a7
bpo-40334: Support CO_FUTURE_BARRY_AS_BDFL in the new parser (GH-19721)
This commit also allows to pass flags to the new parser in all interfaces and fixes a bug in the parser generator that was causing to inline rules with actions, making them disappear.
2020-04-27 18:02:07 +01:00
Pablo Galindo c5fc156852
bpo-40334: PEP 617 implementation: New PEG parser for CPython (GH-19503)
Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
2020-04-22 23:29:27 +01:00
Brandt Bucher be501ca241
bpo-39702: Relax grammar restrictions on decorators (PEP 614) (GH-18570) 2020-03-03 14:25:44 -08:00
Pablo Galindo 8565f6b6db
bpo-35814: Allow unpacking in r.h.s of annotated assignment expressions (GH-13760) 2019-06-03 08:34:20 +01:00
Pablo Galindo 8c77b8cb91
bpo-36540: PEP 570 -- Implementation (GH-12701)
This commit contains the implementation of PEP570: Python positional-only parameters.

* Update Grammar/Grammar with new typedarglist and varargslist

* Regenerate grammar files

* Update and regenerate AST related files

* Update code object

* Update marshal.c

* Update compiler and symtable

* Regenerate importlib files

* Update callable objects

* Implement positional-only args logic in ceval.c

* Regenerate frozen data

* Update standard library to account for positional-only args

* Add test file for positional-only args

* Update other test files to account for positional-only args

* Add News entry

* Update inspect module and related tests
2019-04-29 13:36:57 +01:00
Guido van Rossum 495da29225 bpo-35975: Support parsing earlier minor versions of Python 3 (GH-12086)
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
2019-03-07 12:38:08 -08:00
Xtreak d4fceaafb8 bpo-35877: Make parenthesis optional for named expression in while statement (GH-11724)
* Add parenthesis optional in named expressions for while statement

* Add NEWS entry
2019-02-01 14:40:16 -07:00
Guido van Rossum dcfcd146f8 bpo-35766: Merge typed_ast back into CPython (GH-11645) 2019-01-31 12:40:27 +01:00
Ivan Levkivskyi 62c35a8a8f
bpo-35814: Allow same r.h.s. in annotated assignments as in normal ones (GH-11667) 2019-01-25 01:39:19 +00:00
Emily Morehouse 8f59ee01be
bpo-35224: PEP 572 Implementation (#10497)
* Add tokenization of :=
- Add token to Include/token.h. Add token to documentation in Doc/library/token.rst.
- Run `./python Lib/token.py` to regenerate Lib/token.py.
- Update Parser/tokenizer.c: add case to handle `:=`.

* Add initial usage of := in grammar.

* Update Python.asdl to match the grammar updates. Regenerated Include/Python-ast.h and Python/Python-ast.c

* Update AST and compiler files in Python/ast.c and Python/compile.c. Basic functionality, this isn't scoped properly

* Regenerate Lib/symbol.py using `./python Lib/symbol.py`

* Tests - Fix failing tests in test_parser.py due to changes in token numbers for internal representation

* Tests - Add simple test for := token

* Tests - Add simple tests for named expressions using expr and suite

* Tests - Update number of levels for nested expressions to prevent stack overflow

* Update symbol table to handle NamedExpr

* Update Grammar to allow assignment expressions in if statements.
Regenerate Python/graminit.c accordingly using `make regen-grammar`

* Tests - Add additional tests for named expressions in RoundtripLegalSyntaxTestCase, based on examples and information directly from PEP 572

Note: failing tests are currently commented out (4 out of 24 tests currently fail)

* Tests - Add temporary syntax test failure tests in test_parser.py

Note: There is an outstanding TODO for this -- syntax tests need to be
moved to a different file (presumably test_syntax.py), but this is
covering what needs to be tested at the moment, and it's more convenient
to run a single test for the time being

* Add support for allowing assignment expressions as function argument annotations. Uncomment tests for these cases because they all pass now!

* Tests - Move existing syntax tests out of test_parser.py and into test_named_expressions.py. Refactor syntax tests to use unittest

* Add TargetScopeError exception to extend SyntaxError

Note: This simply creates the TargetScopeError exception, it is not yet
used anywhere

* Tests - Update tests per PEP 572

Continue refactoring test suite:
The named expression test suite now checks for any invalid cases that
throw exceptions (no longer limited to SyntaxErrors), assignment tests
to ensure that variables are properly assigned, and scope tests to
ensure that variable availability and values are correct

Note:
- There are still tests that are marked to skip, as they are not yet
implemented
- There are approximately 300 lines of the PEP that have not yet been
addressed, though these may be deferred

* Documentation - Small updates to XXX/todo comments

- Remove XXX from child description in ast.c
- Add comment with number of previously supported nested expressions for
3.7.X in test_parser.py

* Fix assert in seq_for_testlist()

* Cleanup - Denote "Not implemented -- No keyword args" on failing test case. Fix PEP8 error for blank lines at beginning of test classes in test_parser.py

* Tests - Wrap all file opens in `with...as` to ensure files are closed

* WIP: handle f(a := 1)

* Tests and Cleanup - No longer skips keyword arg test. Keyword arg test now uses a simpler test case and does not rely on an external file. Remove print statements from ast.c

* Tests - Refactor last remaining test case that relied on on external file to use a simpler test case without the dependency

* Tests - Add better description of remaning skipped tests. Add test checking scope when using assignment expression in a function argument

* Tests - Add test for nested comprehension, testing value and scope. Fix variable name in skipped comprehension scope test

* Handle restriction of LHS for named expressions - can only assign to LHS of type NAME. Specifically, restrict assignment to tuples

This adds an alternative set_context specifically for named expressions,
set_namedexpr_context. Thus, context is now set differently for standard
assignment versus assignment for named expressions in order to handle
restrictions.

* Tests - Update negative test case for assigning to lambda to match new error message. Add negative test case for assigning to tuple

* Tests - Reorder test cases to group invalid syntax cases and named assignment target errors

* Tests - Update test case for named expression in function argument - check that result and variable are set correctly

* Todo - Add todo for TargetScopeError based on Guido's comment (2b3acd37bd (r30472562))

* Tests - Add named expression tests for assignment operator in function arguments

Note: One of two tests are skipped, as function arguments are currently treating
an assignment expression inside of parenthesis as one child, which does
not properly catch the named expression, nor does it count arguments
properly

* Add NamedStore to expr_context. Regenerate related code with `make regen-ast`

* Add usage of NamedStore to ast_for_named_expr in ast.c. Update occurances of checking for Store to also handle NamedStore where appropriate

* Add ste_comprehension to _symtable_entry to track if the namespace is a comprehension. Initialize ste_comprehension to 0. Set set_comprehension to 1 in symtable_handle_comprehension

* s/symtable_add_def/symtable_add_def_helper. Add symtable_add_def to handle grabbing st->st_cur and passing it to symtable_add_def_helper. This now allows us to call the original code from symtable_add_def by instead calling symtable_add_def_helper with a different ste.

* Refactor symtable_record_directive to take lineno and col_offset as arguments instead of stmt_ty. This allows symtable_record_directive to be used for stmt_ty and expr_ty

* Handle elevating scope for named expressions in comprehensions.

* Handle error for usage of named expression inside a class block

* Tests - No longer skip scope tests. Add additional scope tests

* Cleanup - Update error message for named expression within a comprehension within a class. Update comments. Add assert for symtable_extend_namedexpr_scope to validate that we always find at least a ModuleScope if we don't find a Class or FunctionScope

* Cleanup - Add missing case for NamedStore in expr_context_name. Remove unused var in set_namedexpr_content

* Refactor - Consolidate set_context and set_namedexpr_context to reduce duplicated code. Special cases for named expressions are handled by checking if ctx is NamedStore

* Cleanup - Add additional use cases for ast_for_namedexpr in usage comment. Fix multiple blank lines in test_named_expressions

* Tests - Remove unnecessary test case. Renumber test case function names

* Remove TargetScopeError for now. Will add back if needed

* Cleanup - Small comment nit for consistency

* Handle positional argument check with named expression

* Add TargetScopeError exception definition. Add documentation for TargetScopeError in c-api docs. Throw TargetScopeError instead of SyntaxError when using a named expression in a comprehension within a class scope

* Increase stack size for parser by 200. This is a minimal change (approx. 5kb) and should not have an impact on any systems. Update parser test to allow 99 nested levels again

* Add TargetScopeError to exception_hierarchy.txt for test_baseexception.py_

* Tests - Major update for named expression tests, both in test_named_expressions and test_parser

- Add test for TargetScopeError
- Add tests for named expressions in comprehension scope and edge cases
- Add tests for named expressions in function arguments (declarations
and call sites)
- Reorganize tests to group them more logically

* Cleanup - Remove unnecessary comment

* Cleanup - Comment nitpicks

* Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)

- Add check for LHS types to detect a parenthesis then a name (see note)
- Add test for this scenario
- Update tests for changed error message for named assignment to a tuple
(also, see note)

Note: This caused issues with the previous error handling for named assignment
to a LHS that contained an expression, such as a tuple. Thus, the check
for the LHS of a named expression must be changed to be more specific if
we wish to maintain the previous error messages

* Cleanup - Wrap lines more strictly in test file

* Revert "Explicitly disallow assignment expressions to a name inside parentheses, e.g.: ((x) := 0)"

This reverts commit f1531400ca7d7a2d148830c8ac703f041740896d.

* Add NEWS.d entry

* Tests - Fix error in test_pickle.test_exceptions by adding TargetScopeError to list of exceptions

* Tests - Update error message tests to reflect improved messaging convention (s/can't/cannot)

* Remove cases that cannot be reached in compile.c. Small linting update.

* Update Grammar/Tokens to add COLONEQUAL. Regenerate all files

* Update TargetScopeError PRE_INIT and POST_INIT, as this was purposefully left out when fixing rebase conflicts

* Add NamedStore back and regenerate files

* Pass along line number and end col info for named expression

* Simplify News entry

* Fix compiler warning and explicity mark fallthrough
2019-01-24 16:49:56 -07:00
Serhiy Storchaka 8ac658114d
bpo-30455: Generate all token related code and docs from Grammar/Tokens. (GH-10370)
"Include/token.h", "Lib/token.py" (containing now some data moved from
"Lib/tokenize.py") and new files "Parser/token.c" (containing the code
moved from "Parser/tokenizer.c") and "Doc/library/token-list.inc" (included
in "Doc/library/token.rst") are now generated from "Grammar/Tokens" by
"Tools/scripts/generate_token.py". The script overwrites files only if
needed and can be used on the read-only sources tree.

"Lib/symbol.py" is now generated by "Tools/scripts/generate_symbol_py.py"
instead of been executable itself.

Added new make targets "regen-token" and "regen-symbol" which are now
dependencies of "regen-all".

The documentation contains now strings for operators and punctuation tokens.
2018-12-22 11:18:40 +02:00
David Cuthbert fd97d1f1af bpo-32117: Allow tuple unpacking in return and yield statements (gh-4509)
Iterable unpacking is now allowed without parentheses in yield and return
statements, e.g. ``yield 1, 2, 3, *rest``. Thanks to David Cuthbert for the
change and jChapman for added tests.
2018-09-21 18:31:15 -07:00
Jelle Zijlstra ac317700ce bpo-30406: Make async and await proper keywords (#1669)
Per PEP 492, 'async' and 'await' should become proper keywords in 3.7.
2017-10-05 23:24:46 -04:00
Lisa Hewus Fresh 384899dfae bpo-30737: Update DevGuide links to new URL (GH-3228)
Update old devguide links from https://docs.python.org/devguide to https://devguide.python.org
2017-08-30 09:37:43 -07:00
Benjamin Peterson ae28ffd944 remove comment about updating the parser module; we do not need to do that anymore (#26526) 2017-01-25 23:35:40 -08:00
Yury Selivanov 52c4e7cc84 Issue #28008: Implement PEP 530 -- asynchronous comprehensions. 2016-09-09 10:36:01 -07:00
Yury Selivanov f8cb8a16a3 Issue #27985: Implement PEP 526 -- Syntax for Variable Annotations.
Patch by Ivan Levkivskyi.
2016-09-08 20:50:03 -07:00