Split the project into separate modules.

build.gradle

@@ -1,20 +1,9 @@
-plugins {
-    id 'java'
-    id 'application'
-    id 'org.jetbrains.kotlin.jvm' version '1.1.3'
-}
-apply plugin: 'java'
-apply plugin: 'application'
+subprojects {
 
-repositories {
-  mavenCentral()
+    apply plugin: 'java'
+
+    repositories {
+      mavenCentral()
+    }
 }
 
-dependencies {
-    compile 'com.moandjiezana.toml:toml4j:0.7.1'
-    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8"
-    testCompile 'junit:junit:4.12'
-}
-
-mainClassName = 'org.nwapw.abacus.Abacus'
-

core/build.gradle

@@ -0,0 +1,9 @@
+plugins {
+    id 'org.jetbrains.kotlin.jvm' version '1.1.3'
+}
+
+dependencies {
+    compile 'com.moandjiezana.toml:toml4j:0.7.1'
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:1.1.3"
+    testCompile 'junit:junit:4.12'
+}

core/src/main/java/org/nwapw/abacus/Abacus.java

@@ -1,7 +1,6 @@
 package org.nwapw.abacus;
 
 import org.nwapw.abacus.config.Configuration;
-import org.nwapw.abacus.fx.AbacusApplication;
 import org.nwapw.abacus.number.NumberInterface;
 import org.nwapw.abacus.parsing.LexerTokenizer;
 import org.nwapw.abacus.parsing.ShuntingYardParser;
@@ -61,10 +60,6 @@ public class Abacus {
         pluginManager.addListener(lexerTokenizer);
     }
 
-    public static void main(String[] args) {
-        AbacusApplication.launch(AbacusApplication.class, args);
-    }
-
     /**
      * Gets the current tree builder.
      *

fx/build.gradle

@@ -0,0 +1,7 @@
+apply plugin: 'application'
+
+dependencies {
+  compile project(':core')
+}
+
+mainClassName = 'org.nwapw.abacus.fx.AbacusApplication'

fx/src/main/java/org/nwapw/abacus/fx/AbacusApplication.java

@@ -33,4 +33,9 @@ public class AbacusApplication extends Application {
         super.stop();
         controller.performStop();
     }
+
+    public static void main(String[] args){
+        launch(args);
+    }
+
 }

settings.gradle

@@ -1 +1,2 @@
 rootProject.name = 'abacus'
+include 'core', 'fx'