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Diffstat (limited to 'docs/programming-guide.md')
-rw-r--r-- | docs/programming-guide.md | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/docs/programming-guide.md b/docs/programming-guide.md index 0c273769bb..07a4d29fe7 100644 --- a/docs/programming-guide.md +++ b/docs/programming-guide.md @@ -41,14 +41,15 @@ In addition, if you wish to access an HDFS cluster, you need to add a dependency artifactId = hadoop-client version = <your-hdfs-version> -Finally, you need to import some Spark classes and implicit conversions into your program. Add the following lines: +Finally, you need to import some Spark classes into your program. Add the following lines: {% highlight scala %} import org.apache.spark.SparkContext -import org.apache.spark.SparkContext._ import org.apache.spark.SparkConf {% endhighlight %} +(Before Spark 1.3.0, you need to explicitly `import org.apache.spark.SparkContext._` to enable essential implicit conversions.) + </div> <div data-lang="java" markdown="1"> @@ -821,11 +822,9 @@ by a key. In Scala, these operations are automatically available on RDDs containing [Tuple2](http://www.scala-lang.org/api/{{site.SCALA_VERSION}}/index.html#scala.Tuple2) objects -(the built-in tuples in the language, created by simply writing `(a, b)`), as long as you -import `org.apache.spark.SparkContext._` in your program to enable Spark's implicit -conversions. The key-value pair operations are available in the +(the built-in tuples in the language, created by simply writing `(a, b)`). The key-value pair operations are available in the [PairRDDFunctions](api/scala/index.html#org.apache.spark.rdd.PairRDDFunctions) class, -which automatically wraps around an RDD of tuples if you import the conversions. +which automatically wraps around an RDD of tuples. For example, the following code uses the `reduceByKey` operation on key-value pairs to count how many times each line of text occurs in a file: |