diff --git a/.gitignore b/.gitignore
index 3343255..2ceb01b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,7 +5,6 @@
 fitnesse/FitNesseRoot/files
 fitnesse/fitnesse-results
 target/
-*.iml
 *.swp
 *.zip
 dependency-reduced-pom.xml
diff --git a/.idea/$PRODUCT_WORKSPACE_FILE$ b/.idea/$PRODUCT_WORKSPACE_FILE$
deleted file mode 100644
index 1f81458..0000000
--- a/.idea/$PRODUCT_WORKSPACE_FILE$
+++ /dev/null
@@ -1,54 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="masterDetails">
-    <states>
-      <state key="GlobalLibrariesConfigurable.UI">
-        <settings>
-          <last-edited>Python 3.6 interpreter library</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-      <state key="JdkListConfigurable.UI">
-        <settings>
-          <last-edited>11</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>1.8</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-      <state key="ProjectLibrariesConfigurable.UI">
-        <settings>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/encodings.xml b/.idea/encodings.xml
index b26911b..942f3a2 100644
--- a/.idea/encodings.xml
+++ b/.idea/encodings.xml
@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="Encoding">
-    <file url="file://$PROJECT_DIR$" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/kotlin" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
   </component>
 </project>
\ No newline at end of file
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
new file mode 100644
index 0000000..712ab9d
--- /dev/null
+++ b/.idea/jarRepositories.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="RemoteRepositoriesConfiguration">
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Central Repository" />
+      <option name="url" value="https://repo.maven.apache.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="central" />
+      <option name="name" value="Maven Central repository" />
+      <option name="url" value="https://repo1.maven.org/maven2" />
+    </remote-repository>
+    <remote-repository>
+      <option name="id" value="jboss.community" />
+      <option name="name" value="JBoss Community repository" />
+      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
+    </remote-repository>
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 5be2610..972ec8d 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ClojureProjectResolveSettings">
-    <currentScheme>IDE</currentScheme>
-  </component>
   <component name="MavenProjectsManager">
     <option name="originalFiles">
       <list>
@@ -10,7 +7,5 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="11" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/classes" />
-  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" project-jdk-name="11" project-jdk-type="JavaSDK" />
 </project>
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index eefb4b3..d5b6698 100644
--- a/pom.xml
+++ b/pom.xml
@@ -10,7 +10,7 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <kotlin.version>1.3.50</kotlin.version>
+    <kotlin.version>1.3.72</kotlin.version>
     <junit5.version>5.3.1</junit5.version>
     <skipTests>false</skipTests>
   </properties>
@@ -201,4 +201,4 @@
     </dependency>
   </dependencies>
 
-</project>
\ No newline at end of file
+</project>
diff --git a/src/main/kotlin/token/TokenFactoryImpl.kt b/src/main/kotlin/token/TokenFactoryImpl.kt
index a60c705..07b3208 100644
--- a/src/main/kotlin/token/TokenFactoryImpl.kt
+++ b/src/main/kotlin/token/TokenFactoryImpl.kt
@@ -20,9 +20,7 @@ class TokenFactoryImpl : TokenFactory {
         if (text.isEmpty())
             throw EmptyTokenTextException(position)
 
-        val firstCharacter = text[0]
-
-        return when (firstCharacter) {
+        return when (val firstCharacter = text[0]) {
             LEFT_PARENTHESIS  -> LeftParenthesis(text, position)
             RIGHT_PARENTHESIS -> RightParenthesis(text, position)
             SINGLE_QUOTE      -> QuoteMark(text, position)
diff --git a/transcendental-lisp.iml b/transcendental-lisp.iml
new file mode 100644
index 0000000..1391d23
--- /dev/null
+++ b/transcendental-lisp.iml
@@ -0,0 +1,66 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
+  <component name="FacetManager">
+    <facet type="kotlin-language" name="Kotlin">
+      <configuration version="3" platform="JVM 1.8" allPlatforms="JVM [1.8]" useProjectSettings="false">
+        <compilerSettings />
+        <compilerArguments>
+          <option name="jvmTarget" value="1.8" />
+          <option name="languageVersion" value="1.3" />
+          <option name="apiVersion" value="1.3" />
+          <option name="pluginOptions">
+            <array />
+          </option>
+          <option name="pluginClasspaths">
+            <array />
+          </option>
+          <option name="errors">
+            <ArgumentParseErrors />
+          </option>
+        </compilerArguments>
+      </configuration>
+    </facet>
+  </component>
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
+    <output url="file://$MODULE_DIR$/target/classes" />
+    <output-test url="file://$MODULE_DIR$/target/test-classes" />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src/main/kotlin" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/src/main/resources" type="java-resource" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/kotlin" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.72" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib:1.3.72" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-common:1.3.72" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains:annotations:13.0" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.72" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-reflect:1.3.72" level="project" />
+    <orderEntry type="library" name="Maven: com.googlecode.lanterna:lanterna:3.0.0" level="project" />
+    <orderEntry type="library" name="Maven: io.github.classgraph:classgraph:4.4.7" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.assertj:assertj-core:3.11.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.junit.jupiter:junit-jupiter-engine:5.3.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.apiguardian:apiguardian-api:1.0.0" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.junit.platform:junit-platform-engine:1.3.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.junit.platform:junit-platform-commons:1.3.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.opentest4j:opentest4j:1.1.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.junit.jupiter:junit-jupiter-api:5.3.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.junit.vintage:junit-vintage-engine:5.3.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.12" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.fitnesse:fitnesse:20180127" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.htmlparser:htmlparser:2.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.htmlparser:htmllexer:2.1" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.apache.velocity:velocity:1.7" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: commons-lang:commons-lang:2.6" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: commons-collections:commons-collections:3.2.2" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.json:json:20151123" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: com.googlecode.java-diff-utils:diffutils:1.3.0" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.apache.ant:ant:1.9.6" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.apache.ant:ant-launcher:1.9.6" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: com.github.stefanbirkner:system-rules:1.18.0" level="project" />
+  </component>
+</module>
\ No newline at end of file