From ab82ee8628f342fe81873fb4d0166f84911f369d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Przemys=C5=82aw=20Pluta?=
 <noreply.git@mx.bartlomiejpluta.com>
Date: Tue, 10 Mar 2020 22:16:40 +0100
Subject: [PATCH] Add support for function/methods invocation on Evaluator

---
 .../dsl/ast/model/node/FunctionCallNode.kt    |  3 +++
 .../evaluator/AccessOperatorEvaluator.kt      | 11 +++++-----
 .../evaluator/ExpressionEvaluator.kt          |  4 +++-
 .../evaluator/FunctionCallEvaluator.kt        | 21 +++++++++++++++++++
 4 files changed, 32 insertions(+), 7 deletions(-)
 create mode 100644 app/src/main/kotlin/io/smnp/evaluation/evaluator/FunctionCallEvaluator.kt

diff --git a/app/src/main/kotlin/io/smnp/dsl/ast/model/node/FunctionCallNode.kt b/app/src/main/kotlin/io/smnp/dsl/ast/model/node/FunctionCallNode.kt
index bc61c0f..387cdfc 100644
--- a/app/src/main/kotlin/io/smnp/dsl/ast/model/node/FunctionCallNode.kt
+++ b/app/src/main/kotlin/io/smnp/dsl/ast/model/node/FunctionCallNode.kt
@@ -1,6 +1,9 @@
 package io.smnp.dsl.ast.model.node
 
 class FunctionCallNode(identifier: Node, arguments: Node) : Node(2, identifier.position) {
+    operator fun component1() = children[0]
+    operator fun component2() = children[1]
+
     val identifier: Node
     get() = children[0]
 
diff --git a/app/src/main/kotlin/io/smnp/evaluation/evaluator/AccessOperatorEvaluator.kt b/app/src/main/kotlin/io/smnp/evaluation/evaluator/AccessOperatorEvaluator.kt
index 981b25a..03eb8d6 100644
--- a/app/src/main/kotlin/io/smnp/evaluation/evaluator/AccessOperatorEvaluator.kt
+++ b/app/src/main/kotlin/io/smnp/evaluation/evaluator/AccessOperatorEvaluator.kt
@@ -1,9 +1,6 @@
 package io.smnp.evaluation.evaluator
 
-import io.smnp.dsl.ast.model.node.AccessOperatorNode
-import io.smnp.dsl.ast.model.node.FunctionCallNode
-import io.smnp.dsl.ast.model.node.IdentifierNode
-import io.smnp.dsl.ast.model.node.Node
+import io.smnp.dsl.ast.model.node.*
 import io.smnp.environment.Environment
 import io.smnp.error.EvaluationException
 import io.smnp.evaluation.model.entity.EvaluatorOutput
@@ -22,8 +19,10 @@ class AccessOperatorEvaluator : Evaluator() {
                 EvaluatorOutput.value(lhs.properties[rhs] ?: throw EvaluationException("Unknown property $rhs of type ${lhs.type.name.toLowerCase()}", rhsNode.position))
             }
             is FunctionCallNode -> {
-                // todo Implement when methods become available
-                EvaluatorOutput.fail()
+                val (identifierNode, argsNode) = rhsNode
+                val identifier = (identifierNode as IdentifierNode).token.rawValue
+                val arguments = (argsNode as FunctionCallArgumentsNode).items.map { evaluator.evaluate(it, environment).value!! }
+                return EvaluatorOutput.value(environment.invokeMethod(lhs, identifier, arguments))
             }
             else -> {
                 throw EvaluationException("Invalid property access type - only property name and method call are allowed", rhsNode.position)
diff --git a/app/src/main/kotlin/io/smnp/evaluation/evaluator/ExpressionEvaluator.kt b/app/src/main/kotlin/io/smnp/evaluation/evaluator/ExpressionEvaluator.kt
index 0dfd4d2..3b46fcd 100644
--- a/app/src/main/kotlin/io/smnp/evaluation/evaluator/ExpressionEvaluator.kt
+++ b/app/src/main/kotlin/io/smnp/evaluation/evaluator/ExpressionEvaluator.kt
@@ -25,7 +25,9 @@ class ExpressionEvaluator : Evaluator() {
             SumOperatorEvaluator(),
             AccessOperatorEvaluator(),
             LogicOperatorEvaluator(),
-            RelationOperatorEvaluator()
+            RelationOperatorEvaluator(),
+
+            FunctionCallEvaluator()
         ).evaluate(node, environment)
 
         if(output.result == EvaluationResult.OK) {
diff --git a/app/src/main/kotlin/io/smnp/evaluation/evaluator/FunctionCallEvaluator.kt b/app/src/main/kotlin/io/smnp/evaluation/evaluator/FunctionCallEvaluator.kt
new file mode 100644
index 0000000..51ca64a
--- /dev/null
+++ b/app/src/main/kotlin/io/smnp/evaluation/evaluator/FunctionCallEvaluator.kt
@@ -0,0 +1,21 @@
+package io.smnp.evaluation.evaluator
+
+import io.smnp.dsl.ast.model.node.FunctionCallArgumentsNode
+import io.smnp.dsl.ast.model.node.FunctionCallNode
+import io.smnp.dsl.ast.model.node.IdentifierNode
+import io.smnp.dsl.ast.model.node.Node
+import io.smnp.environment.Environment
+import io.smnp.evaluation.model.entity.EvaluatorOutput
+
+class FunctionCallEvaluator : Evaluator() {
+    override fun supportedNodes() = listOf(FunctionCallNode::class)
+
+    override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
+        val evaluator = assert(ExpressionEvaluator(), "expression")
+        val (identifierNode, argsNode) = node as FunctionCallNode
+        val identifier = (identifierNode as IdentifierNode).token.rawValue
+        val arguments = (argsNode as FunctionCallArgumentsNode).items.map { evaluator.evaluate(it, environment).value!! }
+
+        return EvaluatorOutput.value(environment.invokeFunction(identifier, arguments))
+    }
+}
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