[Python-Dev] PEP 30XZ: Simplified Parsing (original) (raw)

Ron Adam rrr at ronadam.com
Thu May 3 08:05:38 CEST 2007

Georg Brandl wrote:

FWIW, I'm -1 on both proposals too. I like implicit string literal concatenation and I really can't see what we gain from backslash continuation removal.

Georg

-1 on removing them also. I find they are helpful.

It could be made optional in block headers that end with a ':'. It's optional, (just more white space), in parenthesized expressions, tuples, lists, and dictionary literals already.

[1,
... 2,
... 3] [1, 2, 3]

(1,
... 2,
... 3) (1, 2, 3)

{1:'a',
... 2:'b',
... 3:'c'} {1: 'a', 2: 'b', 3: 'c'}

The rule would be any keyword that starts a block, (class, def, if, elif, with, ... etc.), until an unused (for anything else) colon, would always evaluate to be a single line weather or not it has parentheses or line continuations in it. These can never be multi-line statements as far as I know.

The back slash would still be needed in console input.

The following inconsistency still bothers me, but I suppose it's an edge case that doesn't cause problems.

print r"hello world" File "", line 1 print r"hello world" ^ SyntaxError: EOL while scanning single-quoted string print r"hello
... world" hello
world

In the first case, it's treated as a continuation character even though it's not at the end of a physical line. So it gives an error.

In the second case, its accepted as a continuation character, and a '' character at the same time. (?)

Cheers, Ron

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