Add include-tagged macro

[nik9000]

This macro allows you to include a portion of a file like this:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests}/DeleteDocumentationIT.java[delete-request]
--------------------------------------------------
<1> Index name
<2> Type
<3> Document id

Which can be used to extract a section of a file like this:

        // tag::delete-request
        DeleteRequest request = new DeleteRequest(
            "index",    // <1>
            "type",     // <2>
            "id");      // <3>
        // end::delete-request

[dadoonet]

I gave a quick look at it (well I'm not a Python guy :) ). It looks good.

I guess that automatically find what is the indentation of the tag with indentation = m.group(1).

[nik9000]

I guess that automatically find what is the indentation of the tag with indentation = m.group(1).

Right. We copy the indentation of the tag and strip it from all the other fields. At least, that is what I tried to do.

[nik9000]

I think eval3 should be sys3 actually.

[nik9000]

@clintongormley, do you want to have a look at this?

[clintongormley]

I've improved the error reporting a bit to give the user more context. With that change in place, it's good to merge

[clintongormley]

I'd tidy up the error output a bit, to look more like this:

if __name__ == '__main__':
    from sys import argv, stdout, stderr
    try:
      result = extract_tagged(argv[1], argv[2])
      if result:
          stdout.write(result)
      else:
          raise Exception("Couldn't find tag")
    except Exception as e:
      stderr.write("asciidoc: ERROR: Extracting tag `" + argv[2] + "` from file `" + argv[1]+ "`: " + e.__str__() + "\n")
      exit(1)

[nik9000]

Thanks @clintongormley!