[SPARK-12663] [MLlib] More informative error message in MLUtils.loadLibSVMFile

[robert-dodier]

This PR contains 1 commit which resolves SPARK-12663.

For the record, I got a positive response from 2 people when I floated this idea on dev@spark.apache.org on 2015-10-23. Link to archived discussion.

[SparkQA]

Test build #2332 has finished for PR 10611 at commit 8ae7d35.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[thunterdb]

This line is too long (see spark style guide). Also, I recommend you use scala's string interpolation rather than manually building the string:

s"previous=$previous, line='$line' "

[thunterdb]

@robert-dodier thanks for your PR. Can you please fix the style issue?

[robert-dodier]

OK, thanks for the heads-up. I have pushed commit 237677e which addresses the style problems.

[thunterdb]

cc @jkbradley

[jkbradley]

LGTM pending tests

[SparkQA]

Test build #2340 has finished for PR 10611 at commit 237677e.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[jkbradley]

Merging with master

Thanks!