WIP Add NbtCapabilities.rootTagTypes

src/commonMain/kotlin/BedrockNbt.kt

@@ -9,16 +9,13 @@ import net.benwoodworth.knbt.internal.*
 import net.benwoodworth.knbt.internal.BedrockNbtReader
 import net.benwoodworth.knbt.internal.NbtCapabilities
 import net.benwoodworth.knbt.internal.NbtContext
-import net.benwoodworth.knbt.internal.NbtReader
-import net.benwoodworth.knbt.internal.NbtWriter
 import okio.BufferedSink
 import okio.BufferedSource
-import okio.Sink
-import okio.Source
 
 private val bedrockNbtCapabilities = NbtCapabilities(
     namedRoot = true,
     definiteLengthEncoding = true,
+    rootTagTypes = NbtTagTypeSet(listOf(NbtTagType.TAG_List, NbtTagType.TAG_Compound)),
 )
 
 public class BedrockNbt internal constructor(

src/commonMain/kotlin/BedrockNetworkNbt.kt

@@ -17,6 +17,7 @@ import okio.BufferedSource
 private val bedrockNetworkNbtCapabilities = NbtCapabilities(
     namedRoot = false,
     definiteLengthEncoding = true,
+    rootTagTypes = NbtTagTypeSet(listOf(NbtTagType.TAG_List, NbtTagType.TAG_Compound)),
 )
 
 public class BedrockNetworkNbt internal constructor(

src/commonMain/kotlin/JavaNbt.kt

@@ -5,18 +5,21 @@ import kotlinx.serialization.SerializationException
 import kotlinx.serialization.SerializationStrategy
 import kotlinx.serialization.modules.SerializersModule
 import kotlinx.serialization.serializer
+import net.benwoodworth.knbt.internal.*
 import net.benwoodworth.knbt.internal.BinaryNbtReader
 import net.benwoodworth.knbt.internal.BinaryNbtWriter
 import net.benwoodworth.knbt.internal.JavaNbtReader
 import net.benwoodworth.knbt.internal.JavaNbtWriter
 import net.benwoodworth.knbt.internal.NbtCapabilities
 import net.benwoodworth.knbt.internal.NbtContext
+import net.benwoodworth.knbt.internal.NbtTagTypeSet
 import okio.BufferedSink
 import okio.BufferedSource
 
 private val javaNbtCapabilities = NbtCapabilities(
     namedRoot = true,
     definiteLengthEncoding = true,
+    rootTagTypes = NbtTagTypeSet(listOf(NbtTagType.TAG_Compound)),
 )
 
 public class JavaNbt internal constructor(

src/commonMain/kotlin/JavaNetworkNbt.kt

@@ -17,6 +17,7 @@ import okio.BufferedSource
 private val javaNetworkNbtCapabilities = NbtCapabilities(
     namedRoot = false,
     definiteLengthEncoding = true,
+    rootTagTypes = NbtTagTypeSet(NbtTagType.entries),
 )
 
 public class JavaNetworkNbt internal constructor(

src/commonMain/kotlin/Nbt.kt

@@ -6,10 +6,13 @@ import kotlinx.serialization.SerializationStrategy
 import kotlinx.serialization.modules.SerializersModule
 import kotlinx.serialization.serializer
 import net.benwoodworth.knbt.internal.NbtCapabilities
+import net.benwoodworth.knbt.internal.NbtTagType
+import net.benwoodworth.knbt.internal.NbtTagTypeSet
 
 private val nbtCapabilities = NbtCapabilities(
     namedRoot = true,
     definiteLengthEncoding = true,
+    rootTagTypes = NbtTagTypeSet(NbtTagType.entries),
 )
 
 public open class Nbt internal constructor(

src/commonMain/kotlin/StringifiedNbt.kt

@@ -8,6 +8,7 @@ import kotlin.native.concurrent.ThreadLocal
 private val stringifiedNbtCapabilities = NbtCapabilities(
     namedRoot = false,
     definiteLengthEncoding = false,
+    rootTagTypes = NbtTagTypeSet(NbtTagType.entries - NbtTagType.TAG_End),
 )
 
 public open class StringifiedNbt internal constructor(

src/commonMain/kotlin/internal/NbtCapabilities.kt

@@ -11,4 +11,6 @@ internal data class NbtCapabilities(
      * For deserialization, this means that [CompositeDecoder.decodeSequentially] can be enabled.
      */
     val definiteLengthEncoding: Boolean,
+
+    val rootTagTypes: NbtTagTypeSet,
 )

src/commonMain/kotlin/internal/NbtTagTypeSet.kt

@@ -0,0 +1,28 @@
+package net.benwoodworth.knbt.internal
+
+internal class NbtTagTypeSet(
+    elements: Collection<NbtTagType>
+) {
+    /**
+     * Bits indicating whether each [NbtTagType] in this set, with `1` indicating that it is contained, and
+     * [NbtTagType.bit] assigning bit positions.
+     */
+    private val elementBits: Int =
+        elements.fold(0) { bits, tagType -> bits or tagType.bit }
+
+    private val NbtTagType.bit: Int
+        get() = 1 shl id.toInt()
+
+    operator fun contains(type: NbtTagType): Boolean =
+        (elementBits and type.bit) != 0
+
+    override fun equals(other: Any?): Boolean =
+        this === other || (other is NbtTagTypeSet && elementBits == other.elementBits)
+
+    override fun hashCode(): Int = elementBits
+
+    override fun toString(): String =
+        NbtTagType.entries
+            .filter { it in this }
+            .joinToString(prefix = "[", postfix = "]")
+}

src/commonTest/kotlin/internal/NbtTagTypeSetTest.kt

@@ -0,0 +1,98 @@
+package net.benwoodworth.knbt.internal
+
+import com.benwoodworth.parameterize.parameter
+import net.benwoodworth.knbt.test.assume
+import net.benwoodworth.knbt.test.parameterizeTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNotEquals
+
+class NbtTagTypeSetTest {
+    private class TestCase(
+        private val description: String,
+        val entries: List<NbtTagType>
+    ) {
+        override fun toString(): String = "$description: $entries"
+    }
+
+    private val testCases = buildList {
+        add(TestCase("All", NbtTagType.entries))
+        add(TestCase("None", NbtTagType.entries))
+
+        NbtTagType.entries.forEach { tagType ->
+            add(TestCase("Only $tagType", listOf(tagType)))
+        }
+
+        NbtTagType.entries.forEach { tagType ->
+            add(TestCase("All except $tagType", NbtTagType.entries - tagType))
+        }
+    }
+
+    @Test
+    fun contains_should_be_correct() = parameterizeTest {
+        val testCase by parameter(testCases)
+        val element by parameter(NbtTagType.entries)
+
+        val set = NbtTagTypeSet(testCase.entries)
+
+        assertEquals(element in testCase.entries, element in set, "$element in $set")
+    }
+
+    @Test
+    fun equals_should_be_true_for_same_entries() = parameterizeTest {
+        val testCase by parameter(testCases)
+        val otherTestCase by parameter(testCases)
+        assume(testCase.entries.toSet() == otherTestCase.entries.toSet())
+
+        val set = NbtTagTypeSet(testCase.entries)
+        val otherSet = NbtTagTypeSet(testCase.entries)
+
+        assertEquals(set, otherSet)
+    }
+
+    @Test
+    fun equals_should_be_false_for_different_entries() = parameterizeTest {
+        val testCase by parameter(testCases)
+        val otherTestCase by parameter(testCases)
+        assume(testCase.entries.toSet() != otherTestCase.entries.toSet())
+
+        val set = NbtTagTypeSet(testCase.entries)
+        val otherSet = NbtTagTypeSet(otherTestCase.entries)
+
+        assertNotEquals(set, otherSet)
+    }
+
+    @Test
+    fun hash_code_should_be_the_same_if_equal() = parameterizeTest {
+        val testCase by parameter(testCases)
+        val otherTestCase by parameter(testCases)
+
+        val set = NbtTagTypeSet(testCase.entries)
+        val otherSet = NbtTagTypeSet(otherTestCase.entries)
+        assume(set == otherSet)
+
+        assertEquals(set.hashCode(), otherSet.hashCode())
+    }
+
+    @Test
+    fun hash_code_should_not_be_the_same_if_unequal() = parameterizeTest {
+        val testCase by parameter(testCases)
+        val otherTestCase by parameter(testCases)
+
+        val set = NbtTagTypeSet(testCase.entries)
+        val otherSet = NbtTagTypeSet(otherTestCase.entries)
+        assume(set != otherSet)
+
+        assertNotEquals(set.hashCode(), otherSet.hashCode())
+    }
+
+    @Test
+    fun to_string_should_be_the_same_as_a_set() = parameterizeTest {
+        val testCase by parameter(testCases)
+
+        assertEquals(
+            LinkedHashSet(testCase.entries.sortedBy { it.id }).toString(),
+            NbtTagTypeSet(testCase.entries).toString()
+        )
+    }
+}

src/commonTest/kotlin/test/parameterizeTest.kt

@@ -47,7 +47,6 @@ inline fun ParameterizeScope.assume(condition: Boolean) {
     }
 }
 
-
 // The mapped parameters could be done more seamlessly with context parameters, with the `provideDelegate` and
 // `getValue` operators taking the ParameterizeScope from the calling context instead of explicitly passing the scope
 // and holding onto it. Maybe refactor later once context parameters are available in Kotlin.

src/commonTest/kotlin/test/parameters/ParameterOfVerifyingNbt.kt

@@ -17,6 +17,7 @@ internal fun ParameterizeScope.parameterOfVerifyingNbt(
     val baseCapabilities = NbtCapabilities(
         namedRoot = false,
         definiteLengthEncoding = false,
+        rootTagTypes = NbtTagTypeSet(NbtTagType.entries),
     )
 
     sequenceOf(