Boost C++ Libraries: Ticket #6050: Make spirit::transform_attribute::post return bool instead of void

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oakad@… — Mon, 24 Oct 2011 11:09:35 GMT

attachment → spirit-transform-attribute-post-bool.diff

Patch to make attribute_transform::post return bool

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oakad@… — Tue, 25 Oct 2011 16:19:48 GMT

attachment → spirit-transform-attribute-post-bool-v2.diff

Patch to allow transform_attribute::post to fail the parser; compared to previous version this will set back the input iterator if conversion fails.

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oakad@… — Tue, 25 Oct 2011 16:20:46 GMT

attachment → test_attr.cpp

A short example demonstrating a basic use case for the propoesed change.

oakad@… — Tue, 25 Oct 2011 16:24:55 GMT

Compared to my initial submission, -v2 version of the patch will hold a copy of the input iterator and won't advance it until it can be sure that attribute conversion succeeded. This is analogous to what as<> directive does. Without this minor quirk the facility is not that useful. :-)

I also attached a smallish example which demonstrates the expected functionality.

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oakad@… — Thu, 27 Oct 2011 16:39:39 GMT

attachment → spirit-transform-attribute-post-bool-v3.patch

Added test cases, example and updated documentation

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oakad@… — Sat, 29 Oct 2011 11:04:46 GMT

attachment → spirit-transform-attribute-post-bool-v4.patch

Backtracking in qi::rule now saves the position before the skipper; support for qi::action new attribute transformation behaviour.

Joel de Guzman — Sat, 09 Mar 2013 04:38:21 GMT

I tried to apply this patch but there are some parts being rejected. Could you please update the patch? Thanks!

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oakad@… — Mon, 11 Mar 2013 07:08:19 GMT

attachment → spirit-transform-attribute-post-bool-v5.patch

Updated v4 patch to account for some cosmetic differences in the recent qi version + added some examples missing from the v4 patch.

oakad@… — Mon, 11 Mar 2013 07:12:25 GMT

The only problem I encountered with my patch was slightly shifted line numbers due to some header changes.

Unfortunately, I could not retest it as I'm currently traveling abroad.

Joel de Guzman — Sat, 16 Mar 2013 06:43:41 GMT

I get lots of errors running the tests

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oakad@… — Sun, 17 Mar 2013 14:32:24 GMT

attachment → spirit-transform-attribute-post-bool-v6.patch

Fix an unfortunately missed "bit rot" in v5 arising from changed function attribute names.

oakad@… — Sun, 17 Mar 2013 15:00:55 GMT

Replying to djowel:

I get lots of errors running the tests

Sorry for that. I should have not acted hastily when fixing this patch up. All tests seem to pass just fine with the update, apart from match_manip1.cpp (some problem on my side, may be - it fails with bad_alloc) and regression_stream_eof.cpp (seem to be broken as it is).

status changed; resolution set

Joel de Guzman — Sun, 14 Mar 2021 19:48:45 GMT

status new → closed
resolution → invalid

breaking change, examples are inconclusive for a feature request as the same can be done with exceptions, semantic actions or custom parsers.