Convert to multi-platform project structure

Closes #12

build.gradle.kts

@@ -1,6 +1,5 @@
 import com.github.benmanes.gradle.versions.updates.DependencyUpdatesTask
 import org.jetbrains.dokka.gradle.DokkaTask
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 val ossrhUsername: String? by ext
 val ossrhPassword: String? by ext
@@ -10,7 +9,7 @@ description = "A Result monad for modelling success or failure operations."
 plugins {
     `maven-publish`
     signing
-    kotlin("jvm") version "1.3.72"
+    kotlin("multiplatform") version "1.3.72"
     id("org.jetbrains.dokka") version "0.10.1"
     id("com.github.ben-manes.versions") version "0.28.0"
     id("net.researchgate.release") version "2.8.1"
@@ -18,52 +17,6 @@ plugins {
     id("org.jetbrains.kotlin.plugin.allopen") version "1.3.72"
 }
 
-allprojects {
-    repositories {
-        mavenCentral()
-        jcenter()
-        maven("https://dl.bintray.com/kotlin/kotlinx")
-    }
-
-    tasks.withType<KotlinCompile> {
-        kotlinOptions {
-            jvmTarget = "1.8"
-            freeCompilerArgs = listOf("-Xuse-experimental=kotlin.contracts.ExperimentalContracts")
-        }
-    }
-}
-
-allOpen {
-    annotation("org.openjdk.jmh.annotations.State")
-    annotation("org.openjdk.jmh.annotations.BenchmarkMode")
-}
-
-sourceSets.create("benchmark") {
-    java {
-        srcDir("src/benchmarks/kotlin")
-    }
-}
-
-val benchmarkImplementation by configurations
-
-benchmark {
-    targets {
-        register("benchmark")
-    }
-}
-
-dependencies {
-    implementation(kotlin("stdlib"))
-    testImplementation("junit:junit:4.13")
-    testImplementation(kotlin("test-common"))
-    testImplementation(kotlin("test-annotations-common"))
-    testImplementation(kotlin("test-junit"))
-    testImplementation(kotlin("test"))
-
-    benchmarkImplementation(sourceSets.main.get().output + sourceSets.main.get().runtimeClasspath)
-    benchmarkImplementation("org.jetbrains.kotlinx:kotlinx.benchmark.runtime-jvm:0.2.0-dev-8")
-}
-
 tasks.withType<DependencyUpdatesTask> {
     rejectVersionIf {
         listOf("alpha", "beta", "rc", "cr", "m", "eap", "pr").any {
@@ -85,11 +38,82 @@ val javadocJar by tasks.registering(Jar::class) {
     from(dokka.get().outputDirectory)
 }
 
-val sourcesJar by tasks.registering(Jar::class) {
-    group = LifecycleBasePlugin.BUILD_GROUP
-    description = "Assembles a jar archive containing the main classes with sources."
-    archiveClassifier.set("sources")
-    from(sourceSets["main"].allSource)
+allprojects {
+    repositories {
+        mavenCentral()
+        jcenter()
+        maven("https://dl.bintray.com/kotlin/kotlinx")
+    }
+}
+
+allOpen {
+    annotation("org.openjdk.jmh.annotations.State")
+    annotation("org.openjdk.jmh.annotations.BenchmarkMode")
+}
+
+sourceSets.create("benchmark")
+
+benchmark {
+    targets {
+        register("jvmBenchmark")
+    }
+}
+
+kotlin {
+    jvm {
+        withJava()
+
+        mavenPublication {
+            artifact(javadocJar.get())
+        }
+
+        compilations.all {
+            kotlinOptions {
+                jvmTarget = "1.8"
+            }
+        }
+    }
+
+    sourceSets {
+        all {
+            languageSettings.apply {
+                useExperimentalAnnotation("kotlin.contracts.ExperimentalContracts")
+            }
+        }
+
+        val commonMain by getting {
+            dependencies {
+                implementation(kotlin("stdlib-common"))
+            }
+        }
+
+        val commonTest by getting {
+            dependencies {
+                implementation(kotlin("test-common"))
+                implementation(kotlin("test-annotations-common"))
+            }
+        }
+
+        val jvmMain by getting {
+            dependencies {
+                implementation(kotlin("stdlib-jdk8"))
+            }
+        }
+
+        val jvmTest by getting {
+            dependencies {
+                implementation(kotlin("test-junit"))
+                implementation(kotlin("test"))
+            }
+        }
+
+        val jvmBenchmark by getting {
+            dependsOn(jvmMain)
+            dependencies {
+                implementation("org.jetbrains.kotlinx:kotlinx.benchmark.runtime-jvm:0.2.0-dev-8")
+            }
+        }
+    }
 }
 
 publishing {
@@ -108,12 +132,7 @@ publishing {
         }
     }
 
-    publications {
-        register("mavenJava", MavenPublication::class) {
-            from(components["java"])
-            artifact(javadocJar.get())
-            artifact(sourcesJar.get())
-
+    publications.withType<MavenPublication> {
         pom {
             name.set(project.name)
             description.set(project.description)
@@ -168,7 +187,6 @@ publishing {
             }
         }
     }
-    }
 }
 
 signing {

example/build.gradle.kts

@@ -1,3 +1,5 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
 plugins {
     application
     kotlin("jvm")
@@ -22,3 +24,9 @@ dependencies {
     implementation("io.ktor:ktor-server-netty:$ktorVersion")
     implementation("io.ktor:ktor-gson:$ktorVersion")
 }
+
+tasks.withType(KotlinCompile::class.java).all {
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}

src/commonMain/kotlin/com/github/michaelbull/result/Binding.kt

@@ -38,11 +38,7 @@ inline fun <V, E> binding(crossinline block: ResultBinding<E>.() -> V): Result<V
     }
 }
 
-internal object BindException : Exception() {
-    override fun fillInStackTrace(): Throwable {
-        return this
-    }
-}
+internal expect object BindException : Exception
 
 interface ResultBinding<E> {
     fun <V> Result<V, E>.bind(): V

src/jvmMain/kotlin/com/github/michaelbull/result/BindException.kt

@@ -0,0 +1,7 @@
+package com.github.michaelbull.result
+
+internal actual object BindException : Exception() {
+    override fun fillInStackTrace(): Throwable {
+        return this
+    }
+}