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| author | zsxwing <zsxwing@gmail.com> | 2014-12-01 16:39:54 -0800 |
|---|---|---|
| committer | Michael Armbrust <michael@databricks.com> | 2014-12-01 16:39:54 -0800 |
| commit | d3e02dddf06c82e4baa8708050be291d87d4f367 (patch) | |
| tree | 5a26a1b8d339fb142011360685a584cb9f64d905 /sql/catalyst | |
| parent | 4df60a8cbc58f2877787245c2a83b2de85579c82 (diff) | |
| download | spark-d3e02dddf06c82e4baa8708050be291d87d4f367.tar.gz spark-d3e02dddf06c82e4baa8708050be291d87d4f367.tar.bz2 spark-d3e02dddf06c82e4baa8708050be291d87d4f367.zip | |
[SPARK-4268][SQL] Use #::: to get benefit from Stream in SqlLexical.allCaseVersions
In addition, using `s.isEmpty` to eliminate the string comparison.
Author: zsxwing <zsxwing@gmail.com>
Closes #3132 from zsxwing/SPARK-4268 and squashes the following commits:
358e235 [zsxwing] Improvement of allCaseVersions
Diffstat (limited to 'sql/catalyst')
| -rw-r--r-- | sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SparkSQLParser.scala | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SparkSQLParser.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SparkSQLParser.scala index b198ed9936..f1a1ca6616 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SparkSQLParser.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/SparkSQLParser.scala @@ -97,10 +97,10 @@ class SqlLexical(val keywords: Seq[String]) extends StdLexical { /** Generate all variations of upper and lower case of a given string */ def allCaseVersions(s: String, prefix: String = ""): Stream[String] = { - if (s == "") { + if (s.isEmpty) { Stream(prefix) } else { - allCaseVersions(s.tail, prefix + s.head.toLower) ++ + allCaseVersions(s.tail, prefix + s.head.toLower) #::: allCaseVersions(s.tail, prefix + s.head.toUpper) } } |