[SPARK-10106][SparkR] Add ifelse Column function to SparkR

R/pkg/NAMESPACE

@@ -124,6 +124,7 @@ exportMethods("abs",
               "hex",
               "hour",
               "hypot",
+              "ifelse",
               "initcap",
               "isNaN",
               "isNotNull",

R/pkg/R/functions.R

@@ -179,3 +179,22 @@ setMethod("when", signature(condition = "Column", value = "ANY"),
               jc <- callJStatic("org.apache.spark.sql.functions", "when", condition, value)
               column(jc)
           })
+
+#' ifelse
+#'
+#' Evaluates a list of conditions and returns `yes` if the conditions are satisfied.
+#' Otherwise `no` is returned for unmatched conditions.
+#'
+#' @rdname column
+setMethod("ifelse",
+          signature(test = "Column", yes = "ANY", no = "ANY"),
+          function(test, yes, no) {
+              test <- test@jc
+              yes <- ifelse(class(yes) == "Column", yes@jc, yes)
+              no <- ifelse(class(no) == "Column", no@jc, no)
+              jc <- callJMethod(callJStatic("org.apache.spark.sql.functions",
+                                            "when",
+                                            test, yes),
+                                "otherwise", no)
+              column(jc)
+          })

R/pkg/inst/tests/test_sparkSQL.R

@@ -727,11 +727,12 @@ test_that("greatest() and least() on a DataFrame", {
   expect_equal(collect(select(df, least(df$a, df$b)))[, 1], c(1, 3))
 })
 
-test_that("when() and otherwise() on a DataFrame", {
+test_that("when(), otherwise() and ifelse() on a DataFrame", {
   l <- list(list(a = 1, b = 2), list(a = 3, b = 4))
   df <- createDataFrame(sqlContext, l)
   expect_equal(collect(select(df, when(df$a > 1 & df$b > 2, 1)))[, 1], c(NA, 1))
   expect_equal(collect(select(df, otherwise(when(df$a > 1, 1), 0)))[, 1], c(0, 1))
+  expect_equal(collect(select(df, ifelse(df$a > 1 & df$b > 2, 0, 1)))[, 1], c(1, 0))
 })
 
 test_that("group by", {