1 files changed, 61 insertions, 0 deletions
diff --git a/runtime/commonMain/src/kotlinx/serialization/json/internal/JsonParser.kt b/runtime/commonMain/src/kotlinx/serialization/json/internal/JsonParser.kt
new file mode 100644
index 00000000..34fc4c79
--- /dev/null
+++ b/runtime/commonMain/src/kotlinx/serialization/json/internal/JsonParser.kt
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2017-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization.json.internal
+
+import kotlinx.serialization.json.*
+
+internal class JsonParser(private val reader: JsonReader) {
+
+    private fun readObject(): JsonElement {
+        reader.requireTokenClass(TC_BEGIN_OBJ) { "Expected start of object" }
+        reader.nextToken()
+        val result: MutableMap<String, JsonElement> = linkedMapOf()
+        while (true) {
+            if (reader.tokenClass == TC_COMMA) reader.nextToken()
+            if (!reader.canBeginValue) break
+            val key = reader.takeString()
+            reader.requireTokenClass(TC_COLON) { "Expected ':'" }
+            reader.nextToken()
+            val elem = read()
+            result[key] = elem
+        }
+        reader.requireTokenClass(TC_END_OBJ) { "Expected end of object" }
+        reader.nextToken()
+        return JsonObject(result)
+    }
+
+    private fun readValue(isString: Boolean): JsonElement {
+        val str = reader.takeString()
+        return JsonLiteral(str, isString)
+    }
+
+    private fun readArray(): JsonElement {
+        reader.requireTokenClass(TC_BEGIN_LIST) { "Expected start of array" }
+        reader.nextToken()
+        val result: MutableList<JsonElement> = arrayListOf()
+        while (true) {
+            if (reader.tokenClass == TC_COMMA) reader.nextToken()
+            if (!reader.canBeginValue) break
+            val elem = read()
+            result.add(elem)
+        }
+        reader.requireTokenClass(TC_END_LIST) { "Expected end of array" }
+        reader.nextToken()
+        return JsonArray(result)
+    }
+
+    fun read(): JsonElement {
+        if (!reader.canBeginValue) fail(reader.currentPosition, "Can't begin reading value from here")
+        val tc = reader.tokenClass
+        return when (tc) {
+            TC_NULL -> JsonNull.also { reader.nextToken() }
+            TC_STRING -> readValue(isString = true)
+            TC_OTHER -> readValue(isString = false)
+            TC_BEGIN_OBJ -> readObject()
+            TC_BEGIN_LIST -> readArray()
+            else -> fail(reader.currentPosition, "Can't begin reading element")
+        }
+    }
+}