Include path information in exceptions, and improve location informat…

…ion shown when an invalid type is given for a polymorphic value.

This resolves #37.

src/main/kotlin/com/charleskorn/kaml/YamlException.kt

@@ -18,83 +18,81 @@
 
 package com.charleskorn.kaml
 
-import org.snakeyaml.engine.v2.events.Event
-
 public open class YamlException(
     override val message: String,
-    public val line: Int,
-    public val column: Int,
+    public val path: YamlPath,
     override val cause: Throwable? = null
 ) : RuntimeException(message, cause) {
-    public constructor(message: String, location: Location, cause: Throwable? = null) : this(message, location.line, location.column, cause)
-
-    public val location: Location = Location(line, column)
+    public val location: Location = path.endLocation
+    public val line: Int = location.line
+    public val column: Int = location.column
 
-    override fun toString(): String = "${this::class.qualifiedName} at line $line, column $column: $message"
+    override fun toString(): String = "${this::class.qualifiedName} at ${path.toHumanReadableString()} on line $line, column $column: $message"
 }
 
 public class DuplicateKeyException(
-    public val originalLocation: Location,
-    public val duplicateLocation: Location,
+    public val originalPath: YamlPath,
+    public val duplicatePath: YamlPath,
     public val key: String
 ) :
-    YamlException("Duplicate key $key. It was previously given at line ${originalLocation.line}, column ${originalLocation.column}.", duplicateLocation)
+    YamlException("Duplicate key $key. It was previously given at line ${originalPath.endLocation.line}, column ${originalPath.endLocation.column}.", duplicatePath) {
 
-public class EmptyYamlDocumentException(message: String, location: Location) : YamlException(message, location)
+    public val originalLocation: Location = originalPath.endLocation
+    public val duplicateLocation: Location = duplicatePath.endLocation
+}
+
+public class EmptyYamlDocumentException(message: String, path: YamlPath) : YamlException(message, path)
 
 public class InvalidPropertyValueException(
     public val propertyName: String,
     public val reason: String,
-    location: Location,
+    path: YamlPath,
     cause: Throwable? = null
-) : YamlException("Value for '$propertyName' is invalid: $reason", location, cause)
+) : YamlException("Value for '$propertyName' is invalid: $reason", path, cause)
 
-public class MalformedYamlException(message: String, location: Location) : YamlException(message, location)
+public class MalformedYamlException(message: String, path: YamlPath) : YamlException(message, path)
 
-public class UnexpectedNullValueException(location: Location) : YamlException("Unexpected null or empty value for non-null field.", location)
+public class UnexpectedNullValueException(path: YamlPath) : YamlException("Unexpected null or empty value for non-null field.", path)
 
 public class MissingRequiredPropertyException(
     public val propertyName: String,
-    location: Location,
+    path: YamlPath,
     cause: Throwable? = null
 ) :
-    YamlException("Property '$propertyName' is required but it is missing.", location, cause)
+    YamlException("Property '$propertyName' is required but it is missing.", path, cause)
 
 public class UnknownPropertyException(
     public val propertyName: String,
     public val validPropertyNames: Set<String>,
-    location: Location
+    path: YamlPath
 ) :
-    YamlException("Unknown property '$propertyName'. Known properties are: ${validPropertyNames.sorted().joinToString(", ")}", location)
+    YamlException("Unknown property '$propertyName'. Known properties are: ${validPropertyNames.sorted().joinToString(", ")}", path)
 
 public class UnknownPolymorphicTypeException(
     public val typeName: String,
     public val validTypeNames: Set<String>,
-    location: Location,
+    path: YamlPath,
     cause: Throwable? = null
 ) :
-    YamlException("Unknown type '$typeName'. Known types are: ${validTypeNames.sorted().joinToString(", ")}", location, cause)
+    YamlException("Unknown type '$typeName'. Known types are: ${validTypeNames.sorted().joinToString(", ")}", path, cause)
 
 public class YamlScalarFormatException(
     message: String,
-    location: Location,
+    path: YamlPath,
     public val originalValue: String
-) : YamlException(message, location)
+) : YamlException(message, path)
 
-public open class IncorrectTypeException(message: String, location: Location) : YamlException(message, location)
+public open class IncorrectTypeException(message: String, path: YamlPath) : YamlException(message, path)
 
-public class MissingTypeTagException(location: Location) :
-    IncorrectTypeException("Value is missing a type tag (eg. !<type>)", location)
+public class MissingTypeTagException(path: YamlPath) :
+    IncorrectTypeException("Value is missing a type tag (eg. !<type>)", path)
 
-public class UnknownAnchorException(public val anchorName: String, location: Location) :
-    YamlException("Unknown anchor '$anchorName'.", location)
+public class UnknownAnchorException(public val anchorName: String, path: YamlPath) :
+    YamlException("Unknown anchor '$anchorName'.", path)
 
 public class NoAnchorForExtensionException(
     public val key: String,
     public val extensionDefinitionPrefix: String,
-    location: Location
+    path: YamlPath
 ) :
-    YamlException("The key '$key' starts with the extension definition prefix '$extensionDefinitionPrefix' but does not define an anchor.", location)
-
-internal val Event.location: Location
-    get() = Location(startMark.get().line + 1, startMark.get().column + 1)
+    YamlException("The key '$key' starts with the extension definition prefix '$extensionDefinitionPrefix' but does not define an anchor.", path)