A modest indentation proposal
garth_grimm at hp.com
Fri Nov 30 01:37:41 CET 2001
I think I'd run into more problems with adding lines to the end of block, but forgetting to delete
the ; in what used to be the last line of the block, then I do with 'forgetting' to indent blocks
Erann Gat wrote:
> The subject of syntactically-significant indentation seems to dominate a
> lot of discussions on Python. Personally I've found it to be less of a
> problem than I thought it would be, but annoying nonetheless. It also IMO
> makes the language unsuitable for mission-critical applications. It's
> just too easy to screw up indentation (particularly when cutting and
> pasting large blocks of code) without realizing it.
> I have a suggestion for how to make people like me who are uneasy with
> syntactically significant indentation feel more comfortable while at the
> same time not alienating those who thing that it's a really cool feature.
> The proposal is based on the observation that Python already has the
> equivalent of an open-brace for code blocks. It's the colon. To see that
> this is so you have only to observe that a good editor can automatically
> indent code properly at the beginnings of blocks, but not at the end. The
> solution to the problem is to add an optional end-of-block identifier.
> I propose to use a semicolon at the end of a line to denote the end of a
> block, e.g.:
> for i in l: # Colon signals beginning of block
> baz(); boff() # Semicolon separating statements works as usual
> bar(); # Semicolon at end of line signals end of block
> This convention is 100% backwards-compatible with current practice, that
> is, code written using this convention runs with no problems in Python as
> it currently stands.
> What I would like to see in terms of support for this convention from the
> Python community is two things:
> 1) Editor support for this convention so that a semicolon at the end of a
> line causes the editor to unindent, and
> 2) Parser support. It would be enough to simply give a warning if there
> is a discrepancy between the block structure defined by indentation and
> that defined by the semicolon-at-end-of-line convention (i.e. "Warning:
> end of block detected without trailing semicolon"). Making this optional
> so that die-hard indentation fans could turn it off would also be fine.
> Erann Gat
> gat at jpl.nasa.gov
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