[Please do not mail me a copy of your followup] Jan Herrmann spake the secret code <53E86EED.6070901@gmx.de> thusly:

On 09.08.2014 05:44, Richard wrote:

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[Please do not mail me a copy of your followup]

For a motivating example, see this gist: https://gist.github.com/LegalizeAdulthood/7b67968bd93fbd4f9dbb

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I think http://www.boost.org/doc/libs/1_55_0/libs/utility/doc/html/string_ref.html and http://en.cppreference.com/w/cpp/experimental/basic_string_view could help.

Looks like string_ref is really close to what I was asking for; I'm going to see if I can rework that gist with string_ref. -- "The Direct3D Graphics Pipeline" free book http://tinyurl.com/d3d-pipeline The Computer Graphics Museum http://computergraphicsmuseum.org The Terminals Wiki http://terminals.classiccmp.org Legalize Adulthood! (my blog) http://legalizeadulthood.wordpress.com

On 14.08.2014 03:37, Richard wrote:

[Please do not mail me a copy of your followup]

legalize+jeeves@mail.xmission.com (Richard) spake the secret code thusly:

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Looks like string_ref is really close to what I was asking for; I'm going to see if I can rework that gist with string_ref.

Gist updated to use boost::string_ref: https://gist.github.com/LegalizeAdulthood/7b67968bd93fbd4f9dbb

So string_ref took over the place of the string_chain_segment that I had before.

Now the question remains... is there something that already exists that provides a string_view from a vector of string_ref's?

Range with http://www.boost.org/doc/libs/1_56_0/libs/range/doc/html/range/reference/uti... could help.

As near as I can tell, string_view is a class defined in namespace std that provides a string-like interface over a single char* string. I'm looking to provide an abstraction over a vector.

I can, of course, code one myself, but I'd rather not reinvent the wheel....

Thanks to Jan Herrmann for the pointer to string_ref.

Jan Herrmann

On 15.08.2014 23:52, Richard wrote:

[Please do not mail me a copy of your followup]

Jan Herrmann spake the secret code <53EDB252.9060903@gmx.de> thusly:

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On 14.08.2014 03:37, Richard wrote:

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Now the question remains... is there something that already exists that provides a string_view from a vector of string_ref's?

Range with http://www.boost.org/doc/libs/1_56_0/libs/range/doc/html/range/reference/uti... could help.

Hmm... looks interesting. Obviously that could be used to get a single iterator over two string_ref's.

If I have a chain of string_ref's r1...rN, it looks like I'd have to do:

join(r1, join(r2, join(r3, join(r4, ..., join(rN-1, rN) ...)))

Which doesn't look promising, but I'll give it a go.

I think you will loose an O(1) indexed access but that might not be a problem. To join a container of string_refs std::accumulate could help. Jan Herrmann

On 18.08.2014 10:09, Gordon Woodhull wrote:

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On Aug 18, 2014, at 2:46 AM, Jan Herrmann wrote:

On 15.08.2014 23:52, Richard wrote: [Please do not mail me a copy of your followup]

Jan Herrmann spake the secret code <53EDB252.9060903@gmx.de> thusly:

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On 14.08.2014 03:37, Richard wrote: Now the question remains... is there something that already exists that provides a string_view from a vector of string_ref's?

Range with http://www.boost.org/doc/libs/1_56_0/libs/range/doc/html/range/reference/uti... could help.

Hmm... looks interesting. Obviously that could be used to get a single iterator over two string_ref's.

If I have a chain of string_ref's r1...rN, it looks like I'd have to do:

join(r1, join(r2, join(r3, join(r4, ..., join(rN-1, rN) ...)))

Which doesn't look promising, but I'll give it a go.

I think you will loose an O(1) indexed access but that might not be a problem. To join a container of string_refs std::accumulate could help.

Believe each join type is unique, and type erasure on containers is usually non-performant, so the best you could do is fusion::accumulate - if your sequences were compile-time, which they are clearly no).

The classic data structure for this stuff is a rope, but I don't know of a rope that refers to an outside buffer... :-(

Cheers Gordon

Ok my mistake. So I think a rope for string_ref's has to be implemented. I found twines (http://llvm.org/docs/doxygen/html/Twine_8h_source.html) which look like a rope of variants of string_ref like types. Jan Herrmann

On 8/15/2014 12:10 AM, Jan Herrmann wrote:

On 14.08.2014 03:37, Richard wrote:

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Now the question remains... is there something that already exists that provides a string_view from a vector of string_ref's?

Range with http://www.boost.org/doc/libs/1_56_0/libs/range/doc/html/range/reference/uti... could help.

As Richard discovered for himself, join doesn't help here. What Boost.Range needs is an adaptor that flattens a range of ranges into a range. This is essential functionality, and I describe some of the cool stuff than can be implemented with it here: http://ericniebler.com/2014/04/27/range-comprehensions/ Eric