Re: [boost] Boost.Parser Question about digit separator support

Sorry, no there isn't. The implementation of the number parser will eventually just be std::from_chars. So even if I added support to the Spirit X3 number parsers -- which I use when std::from_chars is unavailable, the support would eventually go away. Also, there are a lot of code paths in the Spirit X3 number parsers, and I wouldn't want to try just jamming such logic in there. The thing I would do is make a rule that produces my number type (say, double). Then I would have a character-based parser that the rule uses, that recognized numbers, and accumulated the characters -- without the separators -- into something like a boost::container::small_vector, and then on success, I'd take have a semantic action call parse() on the small_vector, and assign the result to _val(ctx) for the rule. This sounds like a lot, but it's actually not that much code. I've done this before in other projects that had odd properties in their number representations. Zach On Mon, Mar 4, 2024 at 3:00 AM Olaf Peter via Boost wrote:

Hi all,

In the past I had some attempts with Spirit.x3. C++, VHDL and other languages support literal digit separators. On Stackoverflow.com there are some workarounds (in the context of VHDL's digit separator '_' ) for X3, which works but are unattractive and to unwieldy/unflexible. Is there a native/direct support for it at Boost.Parser?

Thanks, Olaf

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