Enable passing arguments to custom functions

app/src/main/kotlin/io/smnp/callable/function/CustomFunction.kt

@@ -15,15 +15,18 @@ object CustomFunction {
             override fun define(new: FunctionDefinitionTool) {
                 val (_, argumentsNode, bodyNode) = node
                 val signature = FunctionSignatureParser.parseSignature(argumentsNode as FunctionDefinitionArgumentsNode)
-                val evaluator = BlockEvaluator()
+                val evaluator = BlockEvaluator(dedicatedScope = false)
 
                 new function signature body { env, args ->
                     val boundArguments = FunctionEnvironmentProvider.provideEnvironment(argumentsNode, args, env)
-                    // TODO push boundArguments to variables scope
+
                     try {
+                        env.pushScope(boundArguments.toMutableMap())
                         evaluator.evaluate(bodyNode, env)
                     } catch(value: Return) {
                         return@body value.value
+                    } finally {
+                        env.popScope()
                     }
 
                     Value.void()

app/src/main/kotlin/io/smnp/environment/DefaultEnvironment.kt

@@ -79,4 +79,14 @@ class DefaultEnvironment : Environment {
     override fun defineMethod(method: Method) {
         rootModule.addMethod(method)
     }
+
+    override fun pushScope(scope: MutableMap<String, Value>) = callStack.top().pushScope(scope)
+
+    override fun popScope() = callStack.top().popScope()
+
+    override fun printScopes() = callStack.top().prettyScope()
+
+    override fun setVariable(name: String, value: Value) = callStack.top().setVariable(name, value)
+
+    override fun getVariable(name: String) = callStack.top().getVariable(name)
 }

app/src/main/kotlin/io/smnp/evaluation/evaluator/BlockEvaluator.kt

@@ -6,15 +6,18 @@ import io.smnp.environment.Environment
 import io.smnp.evaluation.model.entity.EvaluatorOutput
 import io.smnp.evaluation.model.enumeration.EvaluationResult
 
-class BlockEvaluator : Evaluator() {
+class BlockEvaluator(private val dedicatedScope: Boolean) : Evaluator() {
     override fun supportedNodes() = listOf(BlockNode::class)
 
     override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
         val evaluator = DefaultEvaluator()
+
+        if (dedicatedScope) environment.pushScope()
         val ok = (node as BlockNode).statements.all {
             evaluator.evaluate(it, environment).result != EvaluationResult.FAILED
         }
+        if (dedicatedScope) environment.popScope()
 
-        return if(ok) EvaluatorOutput.ok() else EvaluatorOutput.fail()
+        return if (ok) EvaluatorOutput.ok() else EvaluatorOutput.fail()
     }
 }

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

@@ -10,7 +10,7 @@ class DefaultEvaluator : Evaluator() {
     override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
         return oneOf(
             ConditionEvaluator(),
-            BlockEvaluator(),
+            BlockEvaluator(true),
             ThrowEvaluator(),
             ReturnEvaluator(),
             ExpressionEvaluator()

app/src/main/kotlin/io/smnp/evaluation/evaluator/ExpressionEvaluator.kt

@@ -16,7 +16,8 @@ class ExpressionEvaluator : Evaluator() {
             BoolLiteralEvaluator(), 
             NoteLiteralEvaluator(), 
             ListEvaluator(), 
-            MapEvaluator(), 
+            MapEvaluator(),
+            IdentifierEvaluator(),
 
             MinusOperatorEvaluator(), 
             NotOperatorEvaluator(),

app/src/main/kotlin/io/smnp/evaluation/evaluator/IdentifierEvaluator.kt

@@ -0,0 +1,15 @@
+package io.smnp.evaluation.evaluator
+
+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 IdentifierEvaluator : Evaluator() {
+    override fun supportedNodes() = listOf(IdentifierNode::class)
+
+    override fun tryToEvaluate(node: Node, environment: Environment): EvaluatorOutput {
+        val identifier = (node as IdentifierNode).token.rawValue
+        return EvaluatorOutput.value(environment.getVariable(identifier))
+    }
+}