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by freshhawk
5156 days ago
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In general I agree completely, standard philosophy of science stuff. I'm not sure how well it applies to a subject like best practices where it's either subjective or at least fuzzy. The arguments are "in my experience this causes problems when working with other people and is more prone to errors long term". There have been no counter examples or analysis I've seen around this issue, just a "that's just what the traditionalists say" type argument. Something along the lines of your topcoder example that applied to the semicolon argument (god i hate this issue) would be very welcome. Any critical analysis here is hard to do objectively, and there is a consensus of experts (including Eich) on one side. If i'd seen any actual critical analysis rather than a jump to "don't let the experts tell you what to do! be a rockstar!" then I wouldn't been so fast to use the anti-intellectualism card. But it's so prevalent in the node community (more than Ruby's but less than PHP's) that it's depressing. |
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With semicolons, the search for the boundary between statements reduces to the search for that single character -- that means fast code skimming.
The boundary is also robust against changes; as long as that semicolon stays in place, nothing that happens within that statement can cause that boundary to become an interior.
There is an exception: Strings. This is no trouble for machines, as strings are processed by the lexer. Humans can't instantly take a string and process it as a chunk, but a UI innovation does this work for us: syntax highlighting.
As an example, consider the code:
If I try to change the "b", I might accidentally turn the code into The grammar allows the malformed statement to interact with its neighbor, and thus, instead of getting a parser error, I'll get a program bug.LR parsers take advantage of this for error recovery, allowing them to find more than one parse error at a time.
A more sophisticated view is to think about syntax abstractions. Given a program like "x=y; return x;" we can create a program written in the abstract syntax "statement; statement". (The dual operation is to concretized that back into the set of all two-statement programs. This kind of relationship is known a Galois connection.) Having semicolons makes the abstract syntax unambiguous, allowing us to efficiently reason at the statement level.