In the ideal world, how would we display parsing errors?
This is a follow up on: Truncating SyntaxError - #6 by storchaka and I’m trying to figure out what a protocol needs to support in order to display the error messages the way we want.
Some notes:
-
Displaying bytes in hex is not helpful and is more likely to confuse the user
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File "file.txt", position 3 63 61 66 e9 ^^ UnicodeDecodeError: 'ascii' codec can't decode byte 0xe9: ordinal not in range(128) -
A global offset doesn’t work very well, because newlines can’t be displayed properly in a terminal
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The current error message even mentions the line and column!
re.PatternError: unterminated character set at position 4 (line 2, column 1)Not replaced:
File "<string>", position 4 foo [ ^ re.PatternError: unterminated character setReplaced:
File "<string>", position 4 foo�[ ^ re.PatternError: unterminated character set -
For online resources,
Url "https://link.to/file"is probably better thanFile "<string>".
File "file.py", line 1 | File "file.py", line 1, column 2
[,] | [,]
^ | ^
SyntaxError: invalid syntax | SyntaxError: invalid syntax
---------------------------------------+---------------------------------------
| File "file.json", line 1, column 2
| [,]
| ^
json.decoder.JSONDecodeError: Expectin | json.JSONDecodeError: Expecting value
g value: line 1 column 2 (char 1) |
---------------------------------------+---------------------------------------
| File "<string>", line 1, column 4-5
| café
| ^
UnicodeEncodeError: 'ascii' codec can' | UnicodeEncodeError: 'ascii' codec can'
t encode character '\xe9' in position | t encode character '\xe9: ordinal not
3: ordinal not in range(128) | in range(128)
---------------------------------------+---------------------------------------
| File "file.txt", line 1, column 4-5
| caf�
| ^
UnicodeDecodeError: 'ascii' codec can' | UnicodeDecodeError: 'ascii' codec can'
t decode byte 0xe9 in position 3: ordi | t decode byte 0xe9: ordinal not in ran
nal not in range(128) | ge(128)
| File "<string>", line 1, column 1-1
| +123
| ^
re.PatternError: nothing to repeat at | re.PatternError: nothing to repeat
position 0 |
---------------------------------------+---------------------------------------
| File "file.xml", line 1, column 8-11
| <foo></bar>
| ^^^
xml.parsers.expat.ExpatError: mismatch | xml.parsers.expat.ExpatError: mismatch
ed tag: line 1, column 7 | ed tag
---------------------------------------+---------------------------------------
| File "file.csv", line 1, column 6
| "foo" "bar"
| ^
_csv.Error: ',' expected after '"' | csv.Error: ',' expected after '"'