1 files changed, 61 insertions, 0 deletions
diff --git a/core/src/main/kotlin/Locations/Location.kt b/core/src/main/kotlin/Locations/Location.kt
new file mode 100644
index 00000000..4cb0ac39
--- /dev/null
+++ b/core/src/main/kotlin/Locations/Location.kt
@@ -0,0 +1,61 @@
+package org.jetbrains.dokka
+
+import java.io.File
+
+interface Location {
+    val path: String get
+    fun relativePathTo(other: Location, anchor: String? = null): String
+}
+
+/**
+ * Represents locations in the documentation in the form of [path](File).
+ *
+ * $file: [File] for this location
+ * $path: [String] representing path of this location
+ */
+data class FileLocation(val file: File) : Location {
+    override val path: String
+        get() = file.path
+
+    override fun relativePathTo(other: Location, anchor: String?): String {
+        if (other !is FileLocation) {
+            throw IllegalArgumentException("$other is not a FileLocation")
+        }
+        if (file.path.substringBeforeLast(".") == other.file.path.substringBeforeLast(".") && anchor == null) {
+            return "./${file.name}"
+        }
+        val ownerFolder = file.parentFile!!
+        val relativePath = ownerFolder.toPath().relativize(other.file.toPath()).toString().replace(File.separatorChar, '/')
+        return if (anchor == null) relativePath else relativePath + "#" + anchor
+    }
+}
+
+fun relativePathToNode(qualifiedName: List<String>, hasMembers: Boolean): String {
+    val parts = qualifiedName.map { identifierToFilename(it) }.filterNot { it.isEmpty() }
+    return if (!hasMembers) {
+        // leaf node, use file in owner's folder
+        parts.joinToString("/")
+    } else {
+        parts.joinToString("/") + (if (parts.none()) "" else "/") + "index"
+    }
+}
+
+
+fun relativePathToNode(node: DocumentationNode) = relativePathToNode(node.path.map { it.name }, node.members.any())
+
+fun identifierToFilename(path: String): String {
+    val escaped = path.replace('<', '-').replace('>', '-')
+    val lowercase = escaped.replace("[A-Z]".toRegex()) { matchResult -> "-" + matchResult.value.toLowerCase() }
+    return if (lowercase == "index") "--index--" else lowercase
+}
+
+fun NodeLocationAwareGenerator.relativePathToLocation(owner: DocumentationNode, node: DocumentationNode): String {
+    return location(owner).relativePathTo(location(node), null)
+}
+
+fun NodeLocationAwareGenerator.relativePathToRoot(from: Location): File {
+    val file = File(from.path).parentFile
+    return root.relativeTo(file)
+}
+
+fun File.toUnixString() = toString().replace(File.separatorChar, '/')