refs #35 caching moved to level above objec serializing so we can cache strings, etc that are not Obj instances

lynglib/src/commonMain/kotlin/net/sergeych/lynon/LynonDecoder.kt

@@ -4,27 +4,31 @@ import net.sergeych.lyng.Scope
 import net.sergeych.lyng.obj.Obj
 import net.sergeych.lyng.obj.ObjClass
 
-open class LynonDecoder(private val bin: BitInput) {
+open class LynonDecoder(val bin: BitInput) {
 
     val cache = mutableListOf<Obj>()
 
-    fun unpackObject(scope: Scope, type: ObjClass): Obj {
+    inline fun decodeCached(f: LynonDecoder.() -> Obj): Obj {
         return if( bin.getBit() == 0 ) {
             // unpack and cache
             val cached = bin.getBool()
-            type.deserialize(scope, this).also {
+            f().also {
                 if( cached ) cache.add(it)
             }
         }
         else {
             // get cache reference
             val size = sizeInBits(cache.size)
-            val id = bin.getBitsOrNull(size)?.toInt() ?: scope.raiseError("Invalid object id: unexpected end of stream")
-            if( id >= cache.size ) scope.raiseError("Invalid object id: $id should be in 0..<${cache.size}")
+            val id = bin.getBitsOrNull(size)?.toInt() ?: throw RuntimeException("Invalid object id: unexpected end of stream")
+            if( id >= cache.size ) throw RuntimeException("Invalid object id: $id should be in 0..<${cache.size}")
             cache[id]
         }
     }
 
+    fun unpackObject(scope: Scope, type: ObjClass): Obj {
+        return decodeCached { type.deserialize(scope, this) }
+    }
+
     fun unpackBinaryData(): ByteArray? {
         val size = bin.unpackUnsigned()
         return bin.getBytes(size.toInt())