Improves serialization of Title instances.

Author: hzafar

build.gradle

@@ -15,15 +15,14 @@ java {
 }
 
 dokka {
-    outputFormat = 'html'
+    outputFormat = 'html-as-java'
     outputDirectory = "$buildDir/dokka"
 }
 
 task javadocJar(type: Jar) {
     archiveClassifier = 'javadoc'
     dependsOn dokka
-    from("$buildDir/dokka/isbd-parser")
-    from("$buildDir/dokka/style.css")
+    from("$buildDir/dokka/")
 }
 
 publishing {
@@ -95,6 +94,7 @@ repositories {
 
 dependencies {
     implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
+    implementation 'com.fasterxml.jackson.module:jackson-module-kotlin:2.12.1'
     api 'com.github.norswap:autumn:80abd5c207'
     testImplementation 'junit:junit:4.12'
 }

src/main/kotlin/ca/voidstarzero/isbd/titlestatement/TitleStatementParser.kt

@@ -62,7 +62,7 @@ class TitleStatementParser : TitleStatementGrammar() {
             return result.value_stack.mapNotNull { it as TitleStatement }
         }
 
-        throw Exception(result.toString())
+        return emptyList()
     }
 
     /** Produces all possible parses of the given title statement string.

src/main/kotlin/ca/voidstarzero/isbd/titlestatement/ast/Title.kt

@@ -1,9 +1,18 @@
 package ca.voidstarzero.isbd.titlestatement.ast
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+
 /**
  * Base class for titles.
  */
-sealed class Title() : Node() {}
+@JsonTypeInfo(
+    use = JsonTypeInfo.Id.NAME,
+    include = JsonTypeInfo.As.EXISTING_PROPERTY,
+    property = "type"
+)
+sealed class Title() : Node() {
+    val type = this::class.java.simpleName
+}
 
 /**
  * A class holding the title part of a title statement.