From df0eca9bae4e749b3eb4e304c4aed209255d4d56 Mon Sep 17 00:00:00 2001
From: Oleh Chausov <9oleg8@gmail.com>
Date: Wed, 22 Mar 2023 21:35:01 +0200
Subject: [PATCH] data-types specification

---
 specs/README.md | 63 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/specs/README.md b/specs/README.md
index fb6dcee6..7119195c 100644
--- a/specs/README.md
+++ b/specs/README.md
@@ -43,7 +43,68 @@ zkDatabase isn't just support ordinary Key-Value storage but also support BSON d
 
 ## Data Type
 
-**HELP** We need to clarify which kind of data type will be supported and how could we make it compatible with zkApp (SnarkyJS)
+### SnaryJS supported types
+- **Built-in types**
+    - Field
+    - Bool
+    - UInt32
+    - UInt64
+    - PublicKey
+    - PrivateKey
+    - Signature
+    - Group
+    - Scalar
+    - CircuitString
+    - Character
+- **Custom types**
+    - Struct
+- **Trees**
+    - MerkleTree
+    - MerkleMap
+
+### Bson supported types
+- Double
+- String
+- Object
+- Array
+- Binary data
+- Undefined
+- ObjectId
+- Boolean
+- Date
+- Null
+- Regular Expression
+- DBPointer
+- JavaScript
+- Symbol
+- 32-bit integer
+- Timestamp
+- 64-bit integer
+- Decimal128
+- Min key
+- Max key
+
+### Serialization/Deserialization
+The provided code snippet demonstrates how to convert a zk-snark data type into a BSON-supported format by first converting the value into a Uint8Array and then serializing it using BSON.
+```ts
+  const value = UInt64.from(12342);
+  const bytes: Uint8Array = Encoding.Bijective.Fp.toBytes(value.toFields());
+  const bson = BSON.serialize({ bytes });
+```
+This code snippet demonstrates the process of converting BSON data back into a zk-SNARK data type. This is done by first deserializing the BSON data into a JavaScript object, then converting the Binary data into a Uint8Array, and finally using a built-in decoding method to reconstruct the original value from the byte array.
+```ts
+  const deserializedBson = BSON.deserialize(bson);
+  const convertedResult = new Uint8Array(deserializedBson.bytes.buffer);
+  const initialField = Encoding.Bijective.Fp.fromBytes(convertedResult);
+```
+
+### Serializing Arbitrary Data into Field Elements
+When serializing arbitrary data into field elements, it's important to note that field elements can hold a maximum of 254 arbitrary bits (not 255) due to the largest possible field element lying between 2^254 and 2^255.
+
+You can utilize the `Encoding.bytesToFields` method, which efficiently packs 31 bytes per field element for serialization.
+
+**HELP** We need to clarify which kind of data type will be supported. 
+
 
 ## Index BSON Document