Sure, I'm experimenting with https://github.com/tc39/proposal-standardized-debug/ (just for my own amusement, not planning to try to merge this into v8 anytime soon). I'd like to pass the source text of the argument to debugger.log/break without a lot of overhead (e.g. taking the substring of the stack top's script's source text each time), so only generating it once and using the same string from then on seemed like a good path.
On Monday, 5 October 2020 at 10:34:08 UTC-5 [email protected] wrote: > Our current streaming API + off-thread finalization makes that a bit > tricky, we don't necessarily have the source text when the constant pool is > being filled in. Could you store the positions as raw values in the > constant pool (or as a tuple or whatever) and generate the substring at > runtime? Do you have more details on the underlying problem you're solving? > > On Mon, Oct 5, 2020 at 5:26 PM Gus Caplan <[email protected]> wrote: > >> My ultimate goal is to store the substring in the constant pool. If I >> just store the start/end positions, am I able to get the "current" source >> text when the constant pool is being filled in the bytecode gen? >> On Monday, 5 October 2020 at 02:38:04 UTC-5 [email protected] wrote: >> >>> We don't have an API like that in the scanner/parser, for two reasons: >>> >>> a) Chunking -- data comes to the scanner in chunks (e.g. for streaming), >>> and we do very little rewinding when parsing, so we want to be able to >>> discard chunks once they're no longer needed. >>> b) Escaping -- you can have unicode escapes in strings and even in >>> identifiers, and those should be treated as the equivalent unicode >>> character. >>> >>> So, for things like strings and identifiers, we actually copy the source >>> data into a local buffer while scanning, to be able to turn them into heap >>> strings after. It looks like you want to have a substring representation of >>> the source instead? Would it make sense for you to store the start and end >>> positions, and use those to get a substring of the script's source string? >>> >>> On Sun, Oct 4, 2020 at 6:53 PM Gus Caplan <[email protected]> wrote: >>> >>>> >>>> Hey folks, I'm trying to figure out how to capture a range of source >>>> text in the parser. Ideally the container of the source text is something >>>> that can easily be turned into a heap string. >>>> >>>> int start = peek_position(); >>>> ParseAssignmentExpression(); >>>> int end = end_position(); >>>> auto source = somehow_get_source_text(start, end); >>>> >>>> Any advice is appreciated. >>>> >>>> -- >>>> -- >>>> v8-dev mailing list >>>> [email protected] >>>> http://groups.google.com/group/v8-dev >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "v8-dev" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/v8-dev/f6e9e16a-0335-4005-912c-069009492a0an%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/v8-dev/f6e9e16a-0335-4005-912c-069009492a0an%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> -- >> v8-dev mailing list >> [email protected] >> http://groups.google.com/group/v8-dev >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion on the web visit >> https://groups.google.com/d/msgid/v8-dev/05828843-c480-4ae8-b7d7-9948f3a73f4bn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/v8-dev/05828843-c480-4ae8-b7d7-9948f3a73f4bn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/842515fa-f9db-4f8a-acad-e2a186890a49n%40googlegroups.com.
