Parsing can become accidentally quadratic because of sscanf

Re:Parsing can become accidentally quadratic because of sscanf by minitech on Monday March 01, 2021 @04:17PM (#26308531)

Text is the problem, here and everywhere else. Text encourages looking for delimiters, escaping, and flexibility (optional whitespace, case insensitivity, leading zeros, redundant signs, newline style compatibility). Compared to binary with length prefixes, that’s really slow, prone to injection vulnerabilities and subtle incompatibility, requires copying, introduces more side channels (the length of your message now depends on the values of numbers inside it!), ….

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Re:Parsing can become accidentally quadratic because of sscanf by CivBase on Tuesday March 02, 2021 @09:55AM (#26315922)

Text =/= Variable Length

I can store fixed-length data using text. A strict schema can specify things like fixed lengths, value padding, orders for maps, exact whitespace rules, etc which can entirely remove the need for delimiters. A schema could even require length prefixes, just like you might use for a non-text format.

These concepts do not necessitate abandoning text. If you need the data to be readable/writable by a human with minimal tooling, you can still leverage text without sacrificing much parsing efficiency.

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Re:Parsing can become accidentally quadratic because of sscanf by minitech on Tuesday March 02, 2021 @03:49PM (#26320457)

In theory, sure. In practice, nobody does, and length prefixes stop a format like that from being conveniently writable with a plain text editor.

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Re:Parsing can become accidentally quadratic because of sscanf by CivBase on Tuesday March 02, 2021 @07:19PM (#26323125)

I work on avionics and we definitely use fixed-length text all the time. Text is often much more convenient than blobs, even when adhering to strict schemas.

Syntaxes like XML, JSON, YAML, etc have become popular for their convenience and versatility, but they do not represent the whole of what is possible with text.

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Re:Parsing can become accidentally quadratic because of sscanf by renox on Thursday March 04, 2021 @08:50AM (#26342346)

You've not used enough Ada: its variable length string is so clunky that fixed sized text is used instead..

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Re:Parsing can become accidentally quadratic because of sscanf by deathanatos on Monday March 01, 2021 @11:20PM (#26311874)

And once you get down to it, text still requires tools to parse. I routinely run stuff through `jq`, because despite JSON being a text format, actually consuming it as a human requires a tool. (Often to filter it, but sometimes just to colorize the output to make it legible.)

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