[SPARK-9154][SQL] codegen StringFormat

[tarekbecker]

Jira: https://issues.apache.org/jira/browse/SPARK-9154

fixes bug of #7546

@marmbrus I can't reopen the other PR, because I didn't closed it. Can you trigger Jenkins?

[tarekbecker]

I updated this as well.

[marmbrus]

ok to test

[rxin]

It was my mistake -- I shouldn't have taken out the formatString with Columns, except the 1st argument should be a String.

[tarekbecker]

Should I add it again?

[rxin]

Yes please.

[tarekbecker]

@rxin Could you trigger Jenkins

[marmbrus]

ok to test

[SparkQA]

Test build #37983 has finished for PR 7571 at commit dcae272.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • case class StringFormat(children: Expression*) extends Expression with ImplicitCastInputTypes

[rxin]

Jenkins, retest this please.

[rxin]

i was thinking about a a version in which format is a string, but rest of the arguments are columns.

[SparkQA]

Test build #1150 has finished for PR 7571 at commit dcae272.

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