From e14c0a695ef5a74e4740341cb8a0d27995694db0 Mon Sep 17 00:00:00 2001
From: Alexander Nozik <altavir@gmail.com>
Date: Thu, 11 Aug 2022 17:59:31 +0300
Subject: [PATCH] fix `withDefault`

---
 CHANGELOG.md                                             | 1 +
 .../kotlin/space/kscience/dataforge/meta/Meta.kt         | 5 +++--
 .../kotlin/space/kscience/dataforge/meta/MutableMeta.kt  | 9 ++++-----
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 904cf28c..9528044d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 - More fine-grained types in Action builders.
 
 ### Changed
+- `withDefault` functions do not add new keys to meta children and are consistent.
 - `dataforge.meta.values` package is merged into `dataforge.meta` for better star imports
 - Kotlin 1.7.20
 - `Factory` is now `fun interface` and uses `build` instead of `invoke`. `invoke moved to an extension.
diff --git a/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Meta.kt b/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Meta.kt
index 5cfdded1..0f39942d 100644
--- a/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Meta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/Meta.kt
@@ -248,8 +248,9 @@ public val Meta.stringList: List<String>? get() = value?.list?.map { it.string }
 /**
  * Create a provider that uses given provider for default values if those are not found in this provider
  */
-public fun Meta.withDefault(default: Meta?): Meta = if (default == null) {
+public fun Meta.withDefault(default: MetaProvider?): Meta = if (default == null) {
     this
 } else {
-    Laminate(this, default)
+    //TODO optimize
+    toMutableMeta().withDefault(default)
 }
\ No newline at end of file
diff --git a/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMeta.kt b/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMeta.kt
index 249fad43..ffd1d6e1 100644
--- a/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMeta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/space/kscience/dataforge/meta/MutableMeta.kt
@@ -401,12 +401,12 @@ public inline fun Meta.copy(block: MutableMeta.() -> Unit = {}): Meta =
 
 
 private class MutableMetaWithDefault(
-    val source: MutableMeta, val default: Meta, val rootName: Name
+    val source: MutableMeta, val default: MetaProvider, val rootName: Name
 ) : MutableMeta by source {
     override val items: Map<NameToken, MutableMeta>
         get() {
             val sourceKeys: Collection<NameToken> = source[rootName]?.items?.keys ?: emptyList()
-            val defaultKeys: Collection<NameToken> = default[rootName]?.items?.keys ?: emptyList()
+            val defaultKeys: Collection<NameToken> = default.getMeta(rootName)?.items?.keys ?: emptyList()
             //merging keys for primary and default node
             return (sourceKeys + defaultKeys).associateWith {
                 MutableMetaWithDefault(source, default, rootName + it)
@@ -414,7 +414,7 @@ private class MutableMetaWithDefault(
         }
 
     override var value: Value?
-        get() = source[rootName]?.value ?: default[rootName]?.value
+        get() = source[rootName]?.value ?: default.getMeta(rootName)?.value
         set(value) {
             source[rootName] = value
         }
@@ -430,7 +430,6 @@ private class MutableMetaWithDefault(
  * Create a mutable item provider that uses given provider for default values if those are not found in this provider.
  * Changes are propagated only to this provider.
  */
-public fun MutableMeta.withDefault(default: Meta?): MutableMeta = if (default == null || default.isEmpty()) {
-    //Optimize for use with empty default
+public fun MutableMeta.withDefault(default: MetaProvider?): MutableMeta = if (default == null) {
     this
 } else MutableMetaWithDefault(this, default, Name.EMPTY)