[WX-963] Unzip Engine Function

centaur/src/main/resources/standardTestCases/biscayne_new_engine_functions.test

@@ -58,4 +58,19 @@ metadata {
   "outputs.biscayne_new_engine_functions.with_suffixes.0": "aaaS"
   "outputs.biscayne_new_engine_functions.with_suffixes.1": "bbbS"
   "outputs.biscayne_new_engine_functions.with_suffixes.2": "cccS"
+
+  "outputs.biscayne_new_engine_functions.unzipped_a.left.0": "A"
+  "outputs.biscayne_new_engine_functions.unzipped_a.right.0": "a"
+
+  "outputs.biscayne_new_engine_functions.unzipped_b.left.0": "A"
+  "outputs.biscayne_new_engine_functions.unzipped_b.left.1": "B"
+  "outputs.biscayne_new_engine_functions.unzipped_b.right.0": "a"
+  "outputs.biscayne_new_engine_functions.unzipped_b.right.1": "b"
+
+  "outputs.biscayne_new_engine_functions.unzipped_c.left.0": "one"
+  "outputs.biscayne_new_engine_functions.unzipped_c.left.1": "two"
+  "outputs.biscayne_new_engine_functions.unzipped_c.left.2": "three"
+  "outputs.biscayne_new_engine_functions.unzipped_c.right.0": 1.0
+  "outputs.biscayne_new_engine_functions.unzipped_c.right.1": 2.0
+  "outputs.biscayne_new_engine_functions.unzipped_c.right.2": 3.0
 }

centaur/src/main/resources/standardTestCases/wdl_biscayne/biscayne_new_engine_functions/biscayne_new_engine_functions.wdl

@@ -4,7 +4,7 @@ workflow biscayne_new_engine_functions {
 
   meta {
     description: "This test makes sure that these functions work in a real workflow"
-    functions_under_test: [ "keys", "as_map", "as_pairs", "collect_by_key", "suffix" ]
+    functions_under_test: [ "keys", "as_map", "as_pairs", "collect_by_key", "suffix", "unzip" ]
   }
 
   Map[String, Int] x_map_in = {"a": 1, "b": 2, "c": 3}
@@ -26,6 +26,10 @@ workflow biscayne_new_engine_functions {
   # max float... near enough:
   Float maxFloat = 179769313000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0
 
+  Array[Pair[String,String]] zipped_a = [("A", "a")]
+  Array[Pair[String,String]] zipped_b = [("A", "a"),("B", "b")]
+  Array[Pair[String,Float]] zipped_c = [("one", 1.0),("two", 2.0),("three", 3.0)]
+
   output {
 
     # keys(), as_map(), as_pairs(), collect_by_key():
@@ -54,6 +58,12 @@ workflow biscayne_new_engine_functions {
     # suffix():
     # =================================================
     Array[String] with_suffixes = suffix("S", some_strings)
+
+    # unzip():
+    # =================================================
+    Pair[Array[String], Array[String]] unzipped_a = unzip(zipped_a)
+    Pair[Array[String], Array[String]] unzipped_b = unzip(zipped_b)
+    Pair[Array[String], Array[String]] unzipped_c = unzip(zipped_c)
   }
 }
 

wdl/model/draft3/src/main/scala/wdl/model/draft3/elements/ExpressionElement.scala

@@ -136,6 +136,7 @@ object ExpressionElement {
   final case class Ceil(param: ExpressionElement) extends OneParamFunctionCallElement
   final case class Round(param: ExpressionElement) extends OneParamFunctionCallElement
   final case class Glob(param: ExpressionElement) extends OneParamFunctionCallElement
+  final case class Unzip(param: ExpressionElement) extends OneParamFunctionCallElement
 
   // 1- or 2-param functions:
   sealed trait OneOrTwoParamFunctionCallElement extends FunctionCallElement {

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/ast2wdlom/AstToNewExpressionElements.scala

@@ -3,7 +3,7 @@ package wdl.transforms.biscayne.ast2wdlom
 import cats.syntax.validated._
 import common.validation.ErrorOr.ErrorOr
 import wdl.model.draft3.elements.ExpressionElement
-import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix}
+import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix, Unzip}
 import wdl.transforms.base.ast2wdlom.AstNodeToExpressionElement
 
 object AstToNewExpressionElements {
@@ -16,6 +16,7 @@ object AstToNewExpressionElements {
     "max" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Max, "max"),
     "sep" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Sep, "sep"),
     "suffix" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Suffix, "suffix"),
+    "unzip" -> AstNodeToExpressionElement.validateOneParamEngineFunction(Unzip, "unzip"),
     "read_object" -> (_ =>
       "read_object is no longer available in this WDL version. Consider using read_json instead".invalidNel
     ),

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/consumed/BiscayneExpressionValueConsumers.scala

@@ -66,6 +66,13 @@ object BiscayneExpressionValueConsumers {
         expressionValueConsumer.expressionConsumedValueHooks(a.arg2)(expressionValueConsumer)
   }
 
+  implicit val unzipExpressionValueConsumer: ExpressionValueConsumer[Unzip] = new ExpressionValueConsumer[Unzip] {
+    override def expressionConsumedValueHooks(a: Unzip)(implicit
+      expressionValueConsumer: ExpressionValueConsumer[ExpressionElement]
+    ): Set[UnlinkedConsumedValueHook] =
+      expressionValueConsumer.expressionConsumedValueHooks(a.param)(expressionValueConsumer)
+  }
+
   implicit val noneLiteralExpressionValueConsumer: ExpressionValueConsumer[NoneLiteralElement.type] =
     new ExpressionValueConsumer[NoneLiteralElement.type] {
       override def expressionConsumedValueHooks(a: NoneLiteralElement.type)(implicit

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/consumed/consumed.scala

@@ -104,6 +104,7 @@ package object consumed {
         case a: AsPairs => a.expressionConsumedValueHooks(expressionValueConsumer)
         case a: CollectByKey => a.expressionConsumedValueHooks(expressionValueConsumer)
         case a: Sep => sepExpressionValueConsumer.expressionConsumedValueHooks(a)(expressionValueConsumer)
+        case a: Unzip => a.expressionConsumedValueHooks(expressionValueConsumer)
 
         case a: Min => a.expressionConsumedValueHooks(expressionValueConsumer)
         case a: Max => a.expressionConsumedValueHooks(expressionValueConsumer)

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/files/BiscayneFileEvaluators.scala

@@ -1,6 +1,6 @@
 package wdl.transforms.biscayne.linking.expression.files
 
-import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix}
+import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix, Unzip}
 import wdl.model.draft3.graph.expression.FileEvaluator
 import wdl.transforms.base.linking.expression.files.EngineFunctionEvaluators
 import wdl.transforms.base.linking.expression.files.EngineFunctionEvaluators.twoParameterFunctionPassthroughFileEvaluator
@@ -21,4 +21,6 @@
   implicit val minFunctionEvaluator: FileEvaluator[Min] = twoParameterFunctionPassthroughFileEvaluator[Min]
   implicit val maxFunctionEvaluator: FileEvaluator[Max] = twoParameterFunctionPassthroughFileEvaluator[Max]
 
+  implicit val unzipFunctionEvaluator: FileEvaluator[Unzip] =
+    EngineFunctionEvaluators.singleParameterPassthroughFileEvaluator
 }

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/files/files.scala

@@ -153,6 +153,7 @@
 
         case a: Zip => a.predictFilesNeededToEvaluate(inputs, ioFunctionSet, coerceTo)(fileEvaluator, valueEvaluator)
         case a: Cross => a.predictFilesNeededToEvaluate(inputs, ioFunctionSet, coerceTo)(fileEvaluator, valueEvaluator)
+        case a: Unzip => a.predictFilesNeededToEvaluate(inputs, ioFunctionSet, coerceTo)(fileEvaluator, valueEvaluator)
 
         case a: Sub => a.predictFilesNeededToEvaluate(inputs, ioFunctionSet, coerceTo)(fileEvaluator, valueEvaluator)
 

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/types/BiscayneTypeEvaluators.scala

@@ -110,4 +110,15 @@
        validateParamType(a.array, linkedValues, WomArrayType(WomStringType))
       ) mapN { (_, _) => WomArrayType(WomStringType) }
   }
+
+  implicit val unzipFunctionEvaluator: TypeEvaluator[Unzip] = new TypeEvaluator[Unzip] {
+    override def evaluateType(a: Unzip, linkedValues: Map[UnlinkedConsumedValueHook, GeneratedValueHandle])(implicit
+      expressionTypeEvaluator: TypeEvaluator[ExpressionElement]
+    ): ErrorOr[WomType] =
+      validateParamType(a.param, linkedValues, WomArrayType(WomPairType(WomAnyType, WomAnyType))) flatMap {
+        case WomArrayType(WomNothingType) => WomPairType(WomArrayType(WomAnyType), WomArrayType(WomAnyType)).validNel
+        case WomArrayType(WomPairType(x, y)) => WomPairType(WomArrayType(x), WomArrayType(y)).validNel
+        case other => s"Cannot invoke 'unzip' on type '${other.stableName}'. Expected an array of pairs".invalidNel
+      }
+  }
 }

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/types/types.scala

@@ -97,6 +97,7 @@ package object types {
 
         case a: Zip => a.evaluateType(linkedValues)(typeEvaluator)
         case a: Cross => a.evaluateType(linkedValues)(typeEvaluator)
+        case a: Unzip => a.evaluateType(linkedValues)(typeEvaluator)
 
         case a: Sub => a.evaluateType(linkedValues)(typeEvaluator)
 

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/values/BiscayneValueEvaluators.scala

@@ -235,4 +235,39 @@
         EvaluatedValue(WomArray(arr.value.map(v => WomString(v.valueString + suffix.value))), Seq.empty).validNel
       }
   }
+
+  /**
+   * Unzip: Creates a pair of arrays, the first containing the elements from the left members of an array of pairs,
+   * and the second containing the right members. This is the inverse of the zip function.
+   * https://github.com/openwdl/wdl/blob/main/versions/1.1/SPEC.md#-pairarrayx-arrayy-unziparraypairx-y
+   * input: Array[Pair[X,Y]]
+   * output: Pair[Array[X], Array[Y]]
+   */
+  implicit val unzipFunctionEvaluator: ValueEvaluator[Unzip] = new ValueEvaluator[Unzip] {
+    override def evaluateValue(a: Unzip,
+                               inputs: Map[String, WomValue],
+                               ioFunctionSet: IoFunctionSet,
+                               forCommandInstantiationOptions: Option[ForCommandInstantiationOptions]
+    )(implicit expressionValueEvaluator: ValueEvaluator[ExpressionElement]): ErrorOr[EvaluatedValue[WomPair]] =
+      processValidatedSingleValue[WomArray, WomPair](
+        expressionValueEvaluator.evaluateValue(a.param, inputs, ioFunctionSet, forCommandInstantiationOptions)(
+          expressionValueEvaluator
+        )
+      ) {
+        case WomArray(WomArrayType(WomAnyType), Seq()) =>
+          EvaluatedValue(
+            WomPair(WomArray(WomArrayType(WomAnyType), Seq.empty), WomArray(WomArrayType(WomAnyType), Seq.empty)),
+            Seq.empty
+          ).validNel
+        case WomArray(WomArrayType(WomPairType(_, _)), values) =>
+          val zippedArrayOfPairs: Seq[(WomValue, WomValue)] = values map { case pair: WomPair =>
+            Tuple2(pair.left, pair.right)
+          }
+          val (left, right) = zippedArrayOfPairs.unzip
+          val unzippedPairOfArrays: WomPair = WomPair(WomArray(left), WomArray(right))
+          EvaluatedValue(unzippedPairOfArrays, Seq.empty).validNel
+        case other =>
+          s"Invalid call of 'unzip' on parameter of type '${other.womType.stableName}' (expected Array[Pair[X, Y]])".invalidNel
+      }
+  }
 }

wdl/transforms/biscayne/src/main/scala/wdl/transforms/biscayne/linking/expression/values/values.scala

@@ -164,6 +164,8 @@ package object values {
         case a: Zip => a.evaluateValue(inputs, ioFunctionSet, forCommandInstantiationOptions)(expressionValueEvaluator)
         case a: Cross =>
           a.evaluateValue(inputs, ioFunctionSet, forCommandInstantiationOptions)(expressionValueEvaluator)
+        case a: Unzip =>
+          a.evaluateValue(inputs, ioFunctionSet, forCommandInstantiationOptions)(expressionValueEvaluator)
 
         case a: Sub => a.evaluateValue(inputs, ioFunctionSet, forCommandInstantiationOptions)(expressionValueEvaluator)
 

wdl/transforms/biscayne/src/test/scala/wdl/transforms/biscayne/Ast2WdlomSpec.scala

@@ -103,4 +103,10 @@ class Ast2WdlomSpec extends AnyFlatSpec with CromwellTimeoutSpec with Matchers {
     val expr = fromString[ExpressionElement](str, parser.parse_e)
     expr shouldBeValid (Suffix(IdentifierLookup("some_str"), IdentifierLookup("some_arr")))
   }
+
+  it should "parse the new unzip function" in {
+    val str = "unzip(some_array_of_pairs)"
+    val expr = fromString[ExpressionElement](str, parser.parse_e)
+    expr shouldBeValid (Unzip(IdentifierLookup("some_array_of_pairs")))
+  }
 }

wdl/transforms/biscayne/src/test/scala/wdl/transforms/biscayne/linking/expression/consumed/BiscayneExpressionValueConsumersSpec.scala

@@ -75,4 +75,13 @@ class BiscayneExpressionValueConsumersSpec extends AnyFlatSpec with CromwellTime
       e.expressionConsumedValueHooks should be(Set(UnlinkedIdentifierHook("my_array")))
     }
   }
+
+  it should "discover an array variable lookup within a unzip() call" in {
+    val str = """ unzip(my_array_of_pairs) """
+    val expr = fromString[ExpressionElement](str, parser.parse_e)
+
+    expr.shouldBeValidPF { case e =>
+      e.expressionConsumedValueHooks should be(Set(UnlinkedIdentifierHook("my_array_of_pairs")))
+    }
+  }
 }

wdl/transforms/biscayne/src/test/scala/wdl/transforms/biscayne/linking/expression/files/BiscayneFileEvaluatorSpec.scala

@@ -56,4 +56,15 @@ class BiscayneFileEvaluatorSpec extends AnyFlatSpec with CromwellTimeoutSpec wit
       )
     }
   }
+
+  it should "discover the file which would be required to evaluate a unzip() function" in {
+    val str = """ unzip(read_lines("foo.txt")) """
+    val expr = fromString[ExpressionElement](str, parser.parse_e)
+
+    expr.shouldBeValidPF { case e =>
+      e.predictFilesNeededToEvaluate(Map.empty, NoIoFunctionSet, WomStringType) shouldBeValid Set(
+        WomSingleFile("foo.txt")
+      )
+    }
+  }
 }

wdl/transforms/biscayne/src/test/scala/wdl/transforms/biscayne/linking/expression/types/BiscayneTypeEvaluatorSpec.scala

@@ -64,4 +64,26 @@ class BiscayneTypeEvaluatorSpec extends AnyFlatSpec with CromwellTimeoutSpec wit
       e.evaluateType(Map.empty) shouldBeValid WomArrayType(WomStringType)
     }
   }
+
+  it should "evaluate the type of an unzip() function as Pair[Array[X], Array[Y]]" in {
+    val string_and_int = """ unzip([("one", 1),("two", 2),("three", 3)]) """
+    val string_and_int_expr = fromString[ExpressionElement](string_and_int, parser.parse_e)
+    string_and_int_expr.shouldBeValidPF { case e =>
+      e.evaluateType(Map.empty) shouldBeValid WomPairType(WomArrayType(WomStringType), WomArrayType(WomIntegerType))
+    }
+
+    val int_and_int = """ unzip([(1,2),(3,4),(5,6)]) """
+    val int_and_int_expr = fromString[ExpressionElement](int_and_int, parser.parse_e)
+    int_and_int_expr.shouldBeValidPF { case e =>
+      e.evaluateType(Map.empty) shouldBeValid WomPairType(WomArrayType(WomIntegerType), WomArrayType(WomIntegerType))
+    }
+  }
+
+  it should "evaluate the type of an unzip() function on an empty collection as Pair[Array[Any], Array[Any]]" in {
+    val empty = """ unzip([]) """
+    val empty_unzip_expr = fromString[ExpressionElement](empty, parser.parse_e)
+    empty_unzip_expr.shouldBeValidPF { case e =>
+      e.evaluateType(Map.empty) shouldBeValid WomPairType(WomArrayType(WomAnyType), WomArrayType(WomAnyType))
+    }
+  }
 }

wdl/transforms/biscayne/src/test/scala/wdl/transforms/biscayne/linking/expression/values/BiscayneValueEvaluatorSpec.scala

@@ -11,7 +11,7 @@ import wdl.model.draft3.graph.expression.ValueEvaluator.ops._
 import wdl.transforms.biscayne.Ast2WdlomSpec.{fromString, parser}
 import wdl.transforms.biscayne.ast2wdlom._
 import wom.expression.NoIoFunctionSet
-import wom.types.{WomIntegerType, WomMapType, WomOptionalType, WomStringType}
+import wom.types.{WomAnyType, WomArrayType, WomIntegerType, WomMapType, WomOptionalType, WomStringType}
 import wom.values.{WomArray, WomInteger, WomMap, WomOptionalValue, WomPair, WomString}
 
 class BiscayneValueEvaluatorSpec extends AnyFlatSpec with CromwellTimeoutSpec with Matchers {
@@ -217,4 +217,48 @@ class BiscayneValueEvaluatorSpec extends AnyFlatSpec with CromwellTimeoutSpec wi
       e.evaluateValue(Map.empty, NoIoFunctionSet, None) shouldBeValid EvaluatedValue(expectedArray, Seq.empty)
     }
   }
+
+  it should "evaluate an unzip expression correctly" in {
+    val str = """ unzip([("one", 1),("two", 2),("three", 3)]) """
+    val expr = fromString[ExpressionElement](str, parser.parse_e)
+
+    val left: WomArray =
+      WomArray(WomArrayType(WomStringType), Seq(WomString("one"), WomString("two"), WomString("three")))
+    val right: WomArray = WomArray(WomArrayType(WomIntegerType), Seq(WomInteger(1), WomInteger(2), WomInteger(3)))
+    val expectedPair: WomPair = WomPair(left, right)
+
+    expr.shouldBeValidPF { case e =>
+      e.evaluateValue(Map.empty, NoIoFunctionSet, None) shouldBeValid EvaluatedValue(expectedPair, Seq.empty)
+    }
+  }
+
+  it should "evaluate an unzip on an empty collection correctly" in {
+    val str = """ unzip([])"""
+    val expr = fromString[ExpressionElement](str, parser.parse_e)
+
+    val left: WomArray = WomArray(WomArrayType(WomAnyType), Seq())
+    val right: WomArray = WomArray(WomArrayType(WomAnyType), Seq())
+    val expectedPair: WomPair = WomPair(left, right)
+
+    expr.shouldBeValidPF { case e =>
+      e.evaluateValue(Map.empty, NoIoFunctionSet, None) shouldBeValid EvaluatedValue(expectedPair, Seq.empty)
+    }
+  }
+
+  it should "fail to evaluate unzip on invalid pair" in {
+    val invalidPair = """ unzip([()])"""
+    val invalidPairExpr = fromString[ExpressionElement](invalidPair, parser.parse_e)
+    invalidPairExpr.shouldBeInvalid("Failed to parse expression (reason 1 of 1): No WDL support for 0-tuples")
+  }
+
+  it should "fail to evaluate unzip on heterogeneous pairs" in {
+    val invalidPair = """ unzip([ (1, 11.0), ([1,2,3], 2.0) ])"""
+    val invalidPairExpr = fromString[ExpressionElement](invalidPair, parser.parse_e)
+    invalidPairExpr.map(e =>
+      e.evaluateValue(Map.empty, NoIoFunctionSet, None)
+        .shouldBeInvalid(
+          "Could not construct array of type WomMaybeEmptyArrayType(WomPairType(WomIntegerType,WomFloatType)) with this value: List(WomPair(WomInteger(1),WomFloat(11.0)), WomPair([1, 2, 3],WomFloat(2.0)))"
+        )
+    )
+  }
 }

wdl/transforms/cascades/src/main/scala/wdl/transforms/cascades/ast2wdlom/AstToNewExpressionElements.scala

@@ -3,7 +3,7 @@ package wdl.transforms.cascades.ast2wdlom
 import cats.syntax.validated._
 import common.validation.ErrorOr.ErrorOr
 import wdl.model.draft3.elements.ExpressionElement
-import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix}
+import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix, Unzip}
 import wdl.transforms.base.ast2wdlom.AstNodeToExpressionElement
 
 object AstToNewExpressionElements {
@@ -16,6 +16,7 @@ object AstToNewExpressionElements {
     "max" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Max, "max"),
     "sep" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Sep, "sep"),
     "suffix" -> AstNodeToExpressionElement.validateTwoParamEngineFunction(Suffix, "suffix"),
+    "unzip" -> AstNodeToExpressionElement.validateOneParamEngineFunction(Unzip, "unzip"),
     "read_object" -> (_ =>
       "read_object is no longer available in this WDL version. Consider using read_json instead".invalidNel
     ),

wdl/transforms/cascades/src/main/scala/wdl/transforms/cascades/linking/expression/consumed/CascadesExpressionValueConsumers.scala

@@ -74,4 +74,11 @@
         // None literals consume no values:
         Set.empty[UnlinkedConsumedValueHook]
     }
+
+  implicit val unzipExpressionValueConsumer: ExpressionValueConsumer[Unzip] = new ExpressionValueConsumer[Unzip] {
+    override def expressionConsumedValueHooks(a: Unzip)(implicit
+      expressionValueConsumer: ExpressionValueConsumer[ExpressionElement]
+    ): Set[UnlinkedConsumedValueHook] =
+      expressionValueConsumer.expressionConsumedValueHooks(a.param)(expressionValueConsumer)
+  }
 }

wdl/transforms/cascades/src/main/scala/wdl/transforms/cascades/linking/expression/consumed/consumed.scala

@@ -95,6 +95,7 @@
 
         case a: Zip => a.expressionConsumedValueHooks(expressionValueConsumer)
         case a: Cross => a.expressionConsumedValueHooks(expressionValueConsumer)
+        case a: Unzip => a.expressionConsumedValueHooks(expressionValueConsumer)
 
         case a: Sub => a.expressionConsumedValueHooks(expressionValueConsumer)
 

wdl/transforms/cascades/src/main/scala/wdl/transforms/cascades/linking/expression/files/CascadesFileEvaluators.scala

@@ -1,6 +1,6 @@
 package wdl.transforms.cascades.linking.expression.files
 
-import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix}
+import wdl.model.draft3.elements.ExpressionElement.{AsMap, AsPairs, CollectByKey, Keys, Max, Min, Sep, Suffix, Unzip}
 import wdl.model.draft3.graph.expression.FileEvaluator
 import wdl.transforms.base.linking.expression.files.EngineFunctionEvaluators
 import wdl.transforms.base.linking.expression.files.EngineFunctionEvaluators.twoParameterFunctionPassthroughFileEvaluator
@@ -14,6 +14,8 @@
     EngineFunctionEvaluators.singleParameterPassthroughFileEvaluator
   implicit val collectByKeyFileEvaluator: FileEvaluator[CollectByKey] =
     EngineFunctionEvaluators.singleParameterPassthroughFileEvaluator
+  implicit val unzipFunctionEvaluator: FileEvaluator[Unzip] =
+    EngineFunctionEvaluators.singleParameterPassthroughFileEvaluator
 
   implicit val sepFunctionEvaluator: FileEvaluator[Sep] = twoParameterFunctionPassthroughFileEvaluator[Sep]
   implicit val suffixFunctionEvaluator: FileEvaluator[Suffix] = twoParameterFunctionPassthroughFileEvaluator[Suffix]