Possible issue with dot

[elf-pavlik]

I tried updating levelgraph-n3 to latest version of n3.js, when running this test https://github.com/mcollina/levelgraph-n3/blob/3d3b6d64ea0b028dc9195633d6553e2920252237/test/putStream_spec.js

I started getting

 1) n3.putStream should store some triples:
     Error: Expected punctuation to follow "http://example.org/cartoons#Cat.c:Jerry" at line 1.
      at Object.N3Parser._error (/cache/code/maintain/levelgraph-n3/node_modules/n3/lib/N3Parser.js:457:20)
      at Object.N3Parser._readPunctuation (/cache/code/maintain/levelgraph-n3/node_modules/n3/lib/N3Parser.js:382:19)
...

Adding in test fixture a white space before . (after c:Cat) fixed those symptoms but I don't think (couldn't find in spec) that Turtle requires this white space before .

[RubenVerborgh]

Seeing this error, I suspect that the string http://example.org/cartoons#Cat.c:Jerry occurs somewhere in the input. This is incorrect, since the IRI should be delimited with angular brackets <…>. Can you give the exact Turtle input and expected output?

[elf-pavlik]

you can find exact input in the test i linked to: https://github.com/mcollina/levelgraph-n3/blob/3d3b6d64ea0b028dc9195633d6553e2920252237/test/putStream_spec.js#L6

"@prefix c: <http://example.org/cartoons#>.\n" +
           "c:Tom a c:Cat.\n" +
           "c:Jerry a c:Mouse;\n" +
           "        c:smarterThan c:Tom;\n" +
           "        c:place \"fantasy\".";

adding a space after c:Cat made it work again (it started to fail after only updating N3 from 0.2.3 to 0.3.4

if you like you can just

1. check out levelgraph-n3 repo
2. change N3 dependency to exactly 0.2.3
3. npm install && npm test will pass tests
4. bump N3 to 0.3.4
5. npm install && npm test will fail this one test

[RubenVerborgh]

The problem does not seem to be N3.js-related:

var N3 = require('n3');

var turtle = "@prefix c: <http://example.org/cartoons#>.\n" +
             "c:Tom a c:Cat.\n" +
             "c:Jerry a c:Mouse;\n" +
             "        c:smarterThan c:Tom;\n" +
             "        c:place \"fantasy\".";

new N3.Parser().parse(turtle, console.log);

works fine.

[RubenVerborgh]

It's an issue with the levelgraph-n3 test. It does not generate the above Turtle do the parser, but rather:

@prefix c: <http://example.org/cartoons#>.c:Tom a c:Cat.c:Jerry a c:Mouse;c:smarterThan c:Tom;c:place "fantasy".

This is invalid Turtle, so the parser is correct to reject it.

The bug happens because the test accidentally removes newlines from the Turtle fragment. The following pull request fixes this: mcollina/levelgraph-n3/pull/14

[RubenVerborgh]

BTW The reason for this is that the Turtle spec if different from earlier Turtle drafts, in that it now allows dots as part of prefixed names. Hence, without whitespace after a dot, we cannot disambiguate.

[elf-pavlik]

Thank you!