merkle exec working 1

MERKLE.md

@@ -0,0 +1,358 @@
+# TRICU MERKLE CONTENT STORE — HANDOFF DOC
+
+## Objective
+
+Replace the current **whole-term content store** with a **Merkle DAG–based content store** for Tree Calculus terms.
+
+Goal:
+
+* Canonical, cross-language, content-addressed representation
+* Maximal structural deduplication
+* Clean separation of:
+
+  * identity (hash)
+  * storage (nodes)
+  * transport (packages)
+  * execution (runtime graph)
+
+---
+
+## Current State (contentstore branch)
+
+You currently have:
+
+```text
+Term (T)
+  -> serializeTerm (Cereal)
+  -> sha256(bytes)
+  -> store full term blob
+```
+
+This is:
+
+* canonical at whole-term level
+* NOT deduplicated internally
+* NOT Merkle
+
+---
+
+## Target Architecture
+
+### Core Concept
+
+Each Tree Calculus node becomes a content-addressed object:
+
+```text
+Leaf:
+  hash = H( tag_leaf )
+
+Stem:
+  hash = H( tag_stem || child_hash )
+
+Fork:
+  hash = H( tag_fork || left_hash || right_hash )
+```
+
+Content store:
+
+```text
+Hash -> Node(tag, child_hashes)
+```
+
+A program is:
+
+```text
+root_hash
+```
+
+---
+
+## Data Model (Introduce)
+
+Define a new canonical node type:
+
+```haskell
+data Node
+  = NLeaf
+  | NStem Hash
+  | NFork Hash Hash
+```
+
+Define:
+
+```haskell
+type Hash = ByteString  -- SHA-256
+```
+
+---
+
+## Canonical Serialization (CRITICAL)
+
+Define a **strict, minimal, cross-language spec**:
+
+```text
+Node payload:
+  Leaf: 0x00
+  Stem: 0x01 || child_hash
+  Fork: 0x02 || left_hash || right_hash
+
+Node hash:
+  SHA256( UTF8("tricu.merkle.node.v1") || 0x00 || node_payload )
+
+Store:
+  node_hash -> node_payload
+```
+
+The only thing I would avoid is storing the version inside every node payload unless you need every node to be self-describing. Put it in the hash preimage and in the store/package metadata. That gives versioning without bloating every node.
+
+---
+
+## Required Invariants
+
+These MUST hold:
+
+1. **Determinism**
+
+```text
+same tree → same hashes everywhere
+```
+
+2. **Structural identity**
+
+```text
+identical subtrees → identical hashes
+```
+
+3. **No dependence on DAG shape**
+
+Tree identity must not depend on construction order.
+
+4. **Hash correctness**
+
+```text
+lookup(hash) -> node
+hash(node) == hash
+```
+
+---
+
+## Core Functions to Implement
+
+### 1. Convert Tree → Merkle DAG
+
+```haskell
+buildMerkle :: T -> State Store Hash
+```
+
+Behavior:
+
+* recursively compute child hashes
+* create Node
+* store if not exists
+* return hash
+
+This is the entry point replacing current storage.
+
+---
+
+### 2. Store Interface
+
+```haskell
+putNode :: Node -> StoreM Hash
+getNode :: Hash -> StoreM Node
+```
+
+Store layout can be:
+
+```text
+/data/<hash>
+```
+
+---
+
+### 3. Reconstruct Tree (for execution)
+
+```haskell
+loadTree :: Hash -> StoreM T
+```
+
+Recursive:
+
+* fetch node
+* rebuild T
+* optionally cache
+
+---
+
+### 4. Execution
+
+Reuse existing evaluator:
+
+```haskell
+eval :: T -> T
+```
+
+No change required.
+
+---
+
+## Phase Plan
+
+### Phase 1 — Minimal Merkle Store
+
+* Implement Node type
+* Implement canonical serialization
+* Implement `buildMerkle`
+* Replace current `put` logic
+* Add `loadTree`
+
+Goal: roundtrip correctness
+
+---
+
+### Phase 2 — Dedup Verification
+
+Add diagnostics:
+
+```haskell
+countNodes :: Hash -> Int
+```
+
+Test:
+
+* repeated structures only stored once
+* identical subtrees share hash
+
+---
+
+### Phase 3 — Wire Format
+
+Define transport:
+
+```text
+bundle = compress(
+  list of (hash, serialized_node)
+)
+```
+
+Implement:
+
+```haskell
+exportClosure :: Hash -> Bundle
+importBundle :: Bundle -> StoreM ()
+```
+
+---
+
+### Phase 4 — Runtime Optimization
+
+Optional:
+
+* memoized load
+* DAG-preserving runtime
+* step counter in evaluator
+
+---
+
+## What NOT To Do
+
+Do NOT:
+
+* hash full trees anymore
+* store serialized `T` directly
+* allow multiple encodings
+* include runtime state in nodes
+* depend on evaluation for hashing
+
+---
+
+## Testing Requirements
+
+Add tests for:
+
+### Identity
+
+```text
+same term -> same hash
+```
+
+### Deduplication
+
+```text
+Fork A A stores A once
+```
+
+### Roundtrip
+
+```text
+T -> hash -> loadTree -> T (equal)
+```
+
+### Cross-run stability
+
+Hash must not change between runs
+
+---
+
+## Optional Enhancements
+
+Not required for initial implementation:
+
+* lazy loading
+* partial fetch (networked store)
+* compression at storage layer
+* typed wrappers
+* DAG-aware evaluator
+
+---
+
+## Key Insight
+
+You are not storing programs anymore.
+
+You are storing:
+
+```text
+a canonical graph of computation
+```
+
+Everything else (execution, wire, language) sits on top.
+
+---
+
+## Success Criteria
+
+You know this is working when:
+
+* identical subtrees collapse globally
+* hashes are stable across runs
+* small programs reuse large portions of structure
+* runtime can reconstruct and execute correctly
+* wire bundles can reconstruct store elsewhere
+
+---
+
+## Final Mental Model
+
+```text
+Authoring:        tricu source
+Lowering:         Tree Calculus (T)
+
+Identity:         Merkle hash(root)
+
+Storage:          Merkle DAG (node store)
+
+Wire:             compressed node bundles
+
+Execution:        reconstructed graph → reduce
+```
+
+---
+
+If anything is unclear during implementation, prioritize:
+
+```text
+determinism > simplicity > performance
+```
+
+In order to run tests, simply `nix build .#`. All tests must pass without modification.

src/ContentStore.hs

@@ -20,6 +20,11 @@ import qualified Data.Map             as Map
 import qualified Data.Serialize       as Cereal
 import qualified Data.Text            as T
 
+data StoredNode = StoredNode ByteString deriving (Show)
+
+instance FromRow StoredNode where
+  fromRow = StoredNode <$> field
+
 data StoredTerm = StoredTerm
   { termHash :: Text
   , termNames :: Text
@@ -60,6 +65,9 @@ initContentStore = do
                 \tags TEXT DEFAULT '')"
   execute_ conn "CREATE INDEX IF NOT EXISTS terms_names_idx ON terms(names)"
   execute_ conn "CREATE INDEX IF NOT EXISTS terms_tags_idx ON terms(tags)"
+  execute_ conn "CREATE TABLE IF NOT EXISTS merkle_nodes (\
+                \hash TEXT PRIMARY KEY, \
+                \node_data BLOB NOT NULL)"
   return   conn
 
 getContentStorePath :: IO FilePath
@@ -92,35 +100,83 @@ deserializeTerm :: ByteString -> Either String T
 deserializeTerm = Cereal.decodeLazy . LBS.fromStrict
 
 hashTerm :: T -> Text
-hashTerm = T.pack . show . (hash :: ByteString -> Digest SHA256) . serializeTerm
+hashTerm = nodeHash . buildMerkle
 
 storeTerm :: Connection -> [String] -> T -> IO Text
 storeTerm conn newNamesStrList term = do
+  putStrLn $ "DEBUG: storeTerm called for names " ++ show newNamesStrList
   let termBS = serializeTerm term
       termHashText = hashTerm term
       newNamesTextList = map T.pack newNamesStrList
       metadataText = T.pack "{}"
-
+  putStrLn $ "DEBUG: termHash = " ++ T.unpack termHashText
+  -- Store all Merkle nodes for this term
+  putStrLn "DEBUG: storing merkle nodes"
+  _ <- storeMerkleNodes conn term
+  putStrLn "DEBUG: merkle nodes stored, querying existing"
   existingNamesQuery <- query conn
     "SELECT names FROM terms WHERE hash = ?"
     (Only termHashText) :: IO [Only Text]
+  putStrLn $ "DEBUG: query result = " ++ show (length existingNamesQuery) ++ " results"
 
   case existingNamesQuery of
     [] -> do
+      putStrLn "DEBUG: inserting new term"
       let allNamesToStore = serializeNameList newNamesTextList
       execute conn
         "INSERT INTO terms (hash, names, term_data, metadata, tags) VALUES (?, ?, ?, ?, ?)"
         (termHashText, allNamesToStore, termBS, metadataText, T.pack "")
+      putStrLn "DEBUG: insert complete"
     [(Only currentNamesText)] -> do
+      putStrLn $ "DEBUG: updating existing term, current names = " ++ T.unpack currentNamesText
       let currentNamesList = parseNameList currentNamesText
       let combinedNamesList = currentNamesList ++ newNamesTextList
       let allNamesToStore = serializeNameList combinedNamesList
       execute conn
         "UPDATE terms SET names = ?, metadata = ? WHERE hash = ?"
         (allNamesToStore, metadataText, termHashText)
+      putStrLn "DEBUG: update complete"
+    _ -> error $ "Multiple terms with same hash? " ++ show (length existingNamesQuery)
 
+  putStrLn "DEBUG: storeTerm returning"
   return termHashText
 
+-- | Store all nodes of a Merkle DAG by traversing the Term and building/storing nodes.
+--   Returns the hash of the root node.
+--   This function builds the Merkle DAG while storing nodes, ensuring children are
+--   stored before their parents.
+storeMerkleNodes :: Connection -> T -> IO MerkleHash
+storeMerkleNodes _ Leaf = return $ nodeHash NLeaf  -- NLeaf hash is constant
+storeMerkleNodes conn (Stem t) = do
+  -- Recursively process child first and get its hash
+  childHash <- storeMerkleNodes conn t
+  -- Store this node
+  let thisNode = NStem childHash
+  putMerkleNode conn thisNode
+  return $ nodeHash thisNode
+storeMerkleNodes conn (Fork l r) = do
+  -- Recursively process both children first and get their hashes
+  leftHash <- storeMerkleNodes conn l
+  rightHash <- storeMerkleNodes conn r
+  -- Store this node
+  let thisNode = NFork leftHash rightHash
+  putMerkleNode conn thisNode
+  return $ nodeHash thisNode
+
+
+-- | Insert a Merkle node into the store (idempotent).
+putMerkleNode :: Connection -> Node -> IO ()
+putMerkleNode conn node =
+  execute conn "INSERT OR IGNORE INTO merkle_nodes (hash, node_data) VALUES (?, ?)"
+    (nodeHash node, serializeNode node)
+
+-- | Retrieve a Merkle node by its hash.
+getNodeMerkle :: Connection -> MerkleHash -> IO (Maybe Node)
+getNodeMerkle conn h =
+  queryMaybeOne conn "SELECT node_data FROM merkle_nodes WHERE hash = ?" (Only h) >>= \case
+    Just (StoredNode bs) -> return $ Just (deserializeNode bs)
+    Nothing              -> return Nothing
+
 hashToTerm :: Connection -> Text -> IO (Maybe StoredTerm)
 hashToTerm conn hashText =
   queryMaybeOne conn (selectStoredTermFields <> " WHERE hash = ?") (Only hashText)

src/Research.hs

@@ -1,12 +1,17 @@
 module Research where
 
+import Data.ByteArray            (convert)
+import Data.Char                 (chr, ord)
 import Data.List                 (intercalate)
 import Data.Map                  (Map)
-import Data.Text                 (Text, replace)
+import Data.Text                 (Text, replace, unpack)
+import Data.Word                 (Word8)
 import System.Console.CmdArgs    (Data, Typeable)
 
+import qualified Data.ByteString as BS
 import qualified Data.Map        as Map
-import qualified Data.Text as T
+import qualified Data.Text       as T
+import Crypto.Hash               (hash, SHA256, Digest)
 
 -- Tree Calculus Types
 data T = Leaf | Stem T | Fork T T
@@ -54,6 +59,81 @@ data EvaluatedForm = TreeCalculus | FSL | AST | Ternary | Ascii | Decode
 -- Environment containing previously evaluated TC terms
 type Env = Map.Map String T
 
+-- Merkle DAG Node types
+-- Each Tree Calculus node becomes a content-addressed object.
+
+type MerkleHash = Text
+
+data Node
+  = NLeaf
+  | NStem MerkleHash
+  | NFork MerkleHash MerkleHash
+  deriving (Show, Eq, Ord)
+
+-- | Canonical serialization of a Node for hashing.
+--   Leaf:  0x00
+--   Stem:  0x01 || child_hash (32 bytes)
+--   Fork:  0x02 || left_hash (32 bytes) || right_hash (32 bytes)
+serializeNode :: Node -> BS.ByteString
+serializeNode NLeaf        = BS.pack [0x00]
+serializeNode (NStem h)    = BS.pack [0x01] <> hexToBytes h
+serializeNode (NFork l r)  = BS.pack [0x02] <> hexToBytes l <> hexToBytes r
+
+-- | Hash a node per the Merkle content-addressing spec.
+-- hash = SHA256( "tricu.merkle.node.v1" <> 0x00 <> node_payload )
+nodeHash :: Node -> MerkleHash
+nodeHash node = bytesToHex (sha256WithPrefix (serializeNode node))
+  where sha256WithPrefix payload =
+          convert . (hash :: BS.ByteString -> Digest SHA256) $ utf8Tag <> BS.pack [0x00] <> payload
+        utf8Tag = BS.pack $ map fromIntegral $ BS.unpack "tricu.merkle.node.v1"
+
+-- | Convert a Hex Text hash into raw 32-byte ByteString
+hexToBytes :: Text -> BS.ByteString
+hexToBytes h = BS.pack $ map (uncurry combinePair) pairs
+  where
+    pairs :: [(Char, Char)]
+    pairs = zip (unpack h) (drop 1 $ unpack h)
+    combinePair :: Char -> Char -> Word8
+    combinePair c1 c2 = fromIntegral (nib1 * 16 + nib2)
+      where nib1 = hexDigitToInt c1
+            nib2 = hexDigitToInt c2
+    hexDigitToInt :: Char -> Int
+    hexDigitToInt c
+      | '0' <= c && c <= '9'  = ord c - ord '0'
+      | 'a' <= c && c <= 'f'  = ord c - ord 'a' + 10
+      | 'A' <= c && c <= 'F'  = ord c - ord 'A' + 10
+      | otherwise              = error $ "Invalid hex digit: " ++ show c
+
+-- | Deserialize a Node from canonical bytes.
+deserializeNode :: BS.ByteString -> Node
+deserializeNode bs
+  | BS.null bs || BS.head bs == 0x00 = NLeaf
+  | BS.head bs == 0x01 = NStem $ bytesToHex (BS.take 32 (BS.drop 1 bs))
+  | BS.head bs == 0x02 = NFork (bytesToHex (BS.take 32 (BS.drop 1 bs)))
+                                (bytesToHex (BS.take 32 (BS.drop 33 (BS.drop 1 bs))))
+  | otherwise = error $ "Unknown node type tag: " ++ show (BS.head bs)
+
+-- | Convert 32-byte ByteString back to hex Text
+bytesToHex :: BS.ByteString -> Text
+bytesToHex bs = T.pack $ concatMap byteToHexChars $ BS.unpack bs
+  where
+    byteToHexChars :: Word8 -> String
+    byteToHexChars w = [hexDigit (fromIntegral w `div` 16), hexDigit (fromIntegral w `mod` 16)]
+    hexDigit :: Int -> Char
+    hexDigit n
+      | n < 10    = chr (ord '0' + n)
+      | otherwise = chr (ord 'a' + n - 10)
+
+-- | Build a Merkle DAG from a Tree Calculus term.
+buildMerkle :: T -> Node
+buildMerkle Leaf = NLeaf
+buildMerkle (Stem t) = NStem (nodeHash child)
+  where child = buildMerkle t
+buildMerkle (Fork l r) = NFork (nodeHash left) (nodeHash right)
+  where
+    left  = buildMerkle l
+    right = buildMerkle r
+
 -- Tree Calculus Reduction Rules
 {-
   The t operator is left associative.

tricu.cabal

@@ -39,6 +39,7 @@ executable tricu
     , fsnotify
     , haskeline
     , megaparsec
+    , memory
     , mtl
     , sqlite-simple
     , tasty
@@ -82,6 +83,7 @@ test-suite tricu-tests
     , fsnotify
     , haskeline
     , megaparsec
+    , memory
     , mtl
     , sqlite-simple
     , tasty