Migrate condition evaluator to Kotlin

src/main/kotlin/io/smnp/dsl/ast/model/node/ConditionNode.kt

@@ -1,6 +1,10 @@
 package io.smnp.dsl.ast.model.node
 
 class ConditionNode(trueBranchToken: Node, condition: Node, trueBranch: Node, falseBranchToken: Node, falseBranch: Node) : Node(3, trueBranchToken.position) {
+    operator fun component1(): Node = children[0]
+    operator fun component2(): Node = children[1]
+    operator fun component3(): Node = children[2]
+
     val condition: Node
     get() = children[0]
 

src/main/kotlin/io/smnp/evaluation/evaluator/ConditionEvaluator.kt

@@ -0,0 +1,32 @@
+package io.smnp.evaluation.evaluator
+
+import io.smnp.data.enumeration.DataType
+import io.smnp.dsl.ast.model.node.ConditionNode
+import io.smnp.dsl.ast.model.node.Node
+import io.smnp.dsl.ast.model.node.NoneNode
+import io.smnp.error.EvaluationException
+import io.smnp.evaluation.environment.Environment
+import io.smnp.evaluation.model.entity.EvaluatorOutput
+
+class ConditionEvaluator : Evaluator() {
+    override fun supportedNodes() = listOf(ConditionNode::class)
+
+    override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
+        val expressionEvaluator = ExpressionEvaluator()
+        val defaultEvaluator = DefaultEvaluator()
+        val (conditionNode, trueBranchNode, falseBranchNode) = (node as ConditionNode)
+        val condition = expressionEvaluator.evaluate(conditionNode, environment).value!!
+
+        if(condition.type != DataType.BOOL) {
+            throw EvaluationException("Condition should be of bool type, found '${condition.value}'", conditionNode.position)
+        }
+
+        if(condition.value!! as Boolean) {
+            return defaultEvaluator.evaluate(trueBranchNode, environment)
+        } else if(falseBranchNode !is NoneNode) {
+            return defaultEvaluator.evaluate(falseBranchNode, environment)
+        }
+
+        return EvaluatorOutput.fail()
+    }
+}

src/main/kotlin/io/smnp/evaluation/evaluator/DefaultEvaluator.kt

@@ -9,6 +9,7 @@ class DefaultEvaluator : Evaluator() {
 
     override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
         return oneOf(
+            ConditionEvaluator(),
             BlockEvaluator(),
             ThrowEvaluator(),
             ExpressionEvaluator()