Add Arborix bundle parsing and reconstruction

Implement portable Arborix container, section directory, nodes section, and
Merkle DAG reconstruction utilities in tricu libraries. Add byte/list helper
fixes needed for data-first recursion, validate node payloads, duplicate hashes,
and closed child references, and expose executable loading from a root hash.

Expand binary reader coverage with portable header/section tests, nodes-section
parsing, fixture bundle parsing, and execution checks for reconstructed
id/not?/map roots. Refresh fixture bundles and remove obsolete fixtures.

lib/arborix.tri

@@ -4,6 +4,21 @@
 !import "binary.tri" !Local
 
 arborixMagic = [(65) (82) (66) (79) (82) (73) (88) (0)]
+arborixMajorVersion = [(0) (1)]
+arborixMinorVersion = [(0) (0)]
+arborixManifestSectionId = [(0) (0) (0) (1)]
+arborixNodesSectionId = [(0) (0) (0) (2)]
+
+errMissingSection = 4
+errUnsupportedVersion = 5
+errDuplicateSection = 6
+errDuplicateNode = 7
+errInvalidNodePayload = 8
+errMissingNode = 9
+
+nodePayloadLeafTag = 0
+nodePayloadStemTag = 1
+nodePayloadForkTag = 2
 
 readArborixMagic = (bs : expectBytes arborixMagic bs)
 
@@ -16,43 +31,126 @@ readArborixHeader = (bs :
             (minorVersion afterMinor :
               bindResult (readBytes 4 afterMinor)
                 (sectionCount afterSectionCount :
-                  ok
+                  bindResult (readBytes 8 afterSectionCount)
-                    (pair majorVersion
+                    (flags afterFlags :
-                      (pair minorVersion sectionCount))
+                      bindResult (readBytes 8 afterFlags)
-                    afterSectionCount)))))
+                        (dirOffset afterDirOffset :
+                          ok
+                            (pair majorVersion
+                              (pair minorVersion
+                                (pair sectionCount
+                                  (pair flags dirOffset))))
+                            afterDirOffset)))))))
 
 readSectionRecord = (bs :
-  bindResult (readBytes 2 bs)
+  bindResult (readBytes 4 bs)
     (sectionId afterSectionId :
-      bindResult (readBytes 4 afterSectionId)
+      bindResult (readBytes 2 afterSectionId)
-        (offset afterOffset :
+        (sectionVersion afterSectionVersion :
-          bindResult (readBytes 4 afterOffset)
+          bindResult (readBytes 2 afterSectionVersion)
-            (length afterLength :
+            (sectionFlags afterSectionFlags :
-              ok
+              bindResult (readBytes 2 afterSectionFlags)
-                (pair sectionId
+                (compression afterCompression :
-                  (pair offset length))
+                  bindResult (readBytes 2 afterCompression)
-                afterLength))))
+                    (digestAlgorithm afterDigestAlgorithm :
+                      bindResult (readBytes 8 afterDigestAlgorithm)
+                        (offset afterOffset :
+                          bindResult (readBytes 8 afterOffset)
+                            (length afterLength :
+                              bindResult (readBytes 32 afterLength)
+                                (digest afterDigest :
+                                  ok
+                                    (pair sectionId
+                                      (pair sectionVersion
+                                        (pair sectionFlags
+                                          (pair compression
+                                            (pair digestAlgorithm
+                                              (pair offset
+                                                (pair length digest)))))))
+                                    afterDigest)))))))))
 
-readSectionDirectory_ = y (self sectionCount i bs acc :
+readSectionDirectory_ = y (self bs sectionCount i acc :
   matchBool
     (ok (reverse acc) bs)
     (bindResult (readSectionRecord bs)
       (sectionRecord afterSectionRecord :
-        self sectionCount (succ i) afterSectionRecord (pair sectionRecord acc)))
+        self afterSectionRecord sectionCount (succ i) (pair sectionRecord acc)))
     (equal? i sectionCount))
 
-readSectionDirectory = (sectionCount bs : readSectionDirectory_ sectionCount 0 bs t)
+readSectionDirectory = (sectionCount bs : readSectionDirectory_ bs sectionCount 0 t)
 
 sectionRecordId = (sectionRecord :
   matchPair
     (sectionId _ : sectionId)
     sectionRecord)
 
+sectionRecordVersion = (sectionRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (sectionVersion _ : sectionVersion)
+        payload)
+    sectionRecord)
+
+sectionRecordFlags = (sectionRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (sectionFlags _ : sectionFlags)
+            payload2)
+        payload)
+    sectionRecord)
+
+sectionRecordCompression = (sectionRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (compression _ : compression)
+                payload3)
+            payload2)
+        payload)
+    sectionRecord)
+
+sectionRecordDigestAlgorithm = (sectionRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (_ payload4 :
+                  matchPair
+                    (digestAlgorithm _ : digestAlgorithm)
+                    payload4)
+                payload3)
+            payload2)
+        payload)
+    sectionRecord)
+
 sectionRecordOffset = (sectionRecord :
   matchPair
     (_ payload :
       matchPair
-        (offset _ : offset)
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (_ payload4 :
+                  matchPair
+                    (_ payload5 :
+                      matchPair
+                        (offset _ : offset)
+                        payload5)
+                    payload4)
+                payload3)
+            payload2)
         payload)
     sectionRecord)
 
@@ -60,18 +158,497 @@ sectionRecordLength = (sectionRecord :
   matchPair
     (_ payload :
       matchPair
-        (_ length : length)
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (_ payload4 :
+                  matchPair
+                    (_ payload5 :
+                      matchPair
+                        (_ payload6 :
+                          matchPair
+                            (length _ : length)
+                            payload6)
+                        payload5)
+                    payload4)
+                payload3)
+            payload2)
         payload)
     sectionRecord)
 
-lookupSectionRecord = y (self sectionId directory :
+sectionRecordDigest = (sectionRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (_ payload4 :
+                  matchPair
+                    (_ payload5 :
+                      matchPair
+                        (_ payload6 :
+                          matchPair
+                            (_ digest : digest)
+                            payload6)
+                        payload5)
+                    payload4)
+                payload3)
+            payload2)
+        payload)
+    sectionRecord)
+
+lookupSectionRecord_ = y (self directory sectionId :
   matchList
     nothing
     (sectionRecord rest :
       matchBool
         (just sectionRecord)
-        (self sectionId rest)
+        (self rest sectionId)
         (bytesEq? sectionId (sectionRecordId sectionRecord)))
     directory)
 
+lookupSectionRecord = (sectionId directory : lookupSectionRecord_ directory sectionId)
+
+sectionDirectoryHasId?_ = y (self directory sectionId :
+  matchList
+    false
+    (sectionRecord rest :
+      or?
+        (bytesEq? sectionId (sectionRecordId sectionRecord))
+        (self rest sectionId))
+    directory)
+
+sectionDirectoryHasId? = (sectionId directory : sectionDirectoryHasId?_ directory sectionId)
+
+sectionDirectoryHasDuplicateIds? = y (self directory :
+  matchList
+    false
+    (sectionRecord rest :
+      or?
+        (sectionDirectoryHasId?_ rest (sectionRecordId sectionRecord))
+        (self rest))
+    directory)
+
+validateSectionDirectory = (directory rest :
+  matchBool
+    (err errDuplicateSection rest)
+    (ok directory rest)
+    (sectionDirectoryHasDuplicateIds? directory))
+
 byteSlice = (offset length bytes : bytesTake length (bytesDrop offset bytes))
+
+natMake = (bit rest :
+  matchBool
+    0
+    (pair bit rest)
+    (and? (equal? bit 0) (equal? rest 0)))
+
+natAdd = y (self a b :
+  triage
+    b
+    (_ : b)
+    (aBit aRest :
+      triage
+        a
+        (_ : a)
+        (bBit bRest :
+          matchBool
+            (natMake 0 (succ (self aRest bRest)))
+            (natMake (matchBool (matchBool 0 1 bBit) (matchBool 1 0 bBit) aBit)
+              (self aRest bRest))
+            (and? (equal? aBit 1) (equal? bBit 1)))
+        b)
+    a)
+
+natDouble = (n : matchBool 0 (pair 0 n) (equal? n 0))
+
+natTimes256 = (n :
+  natDouble
+    (natDouble
+      (natDouble
+        (natDouble
+          (natDouble
+            (natDouble
+              (natDouble
+                (natDouble n))))))))
+
+byteNatShiftAppend_ = y (self byte acc i :
+  matchBool
+    acc
+    (triage
+      (natMake 0 (self 0 acc (succ i)))
+      (_ : acc)
+      (bit rest : natMake bit (self rest acc (succ i)))
+      byte)
+    (equal? i 8))
+
+byteNatShiftAppend = (byte acc : byteNatShiftAppend_ byte acc 0)
+
+beBytesToNat = (bytes :
+  foldl
+    (acc byte : byteNatShiftAppend byte acc)
+    0
+    bytes)
+
+u32BEBytesToNat = beBytesToNat
+u64BEBytesToNat = beBytesToNat
+
+arborixHeaderMajorVersion = (header :
+  matchPair
+    (majorVersion _ : majorVersion)
+    header)
+
+arborixHeaderMinorVersion = (header :
+  matchPair
+    (_ payload :
+      matchPair
+        (minorVersion _ : minorVersion)
+        payload)
+    header)
+
+arborixHeaderSectionCount = (header :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (sectionCount _ : sectionCount)
+            payload2)
+        payload)
+    header)
+
+arborixHeaderFlags = (header :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (flags _ : flags)
+                payload3)
+            payload2)
+        payload)
+    header)
+
+arborixHeaderDirOffset = (header :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ payload2 :
+          matchPair
+            (_ payload3 :
+              matchPair
+                (_ dirOffset : dirOffset)
+                payload3)
+            payload2)
+        payload)
+    header)
+
+validateArborixHeader = (header rest :
+  matchBool
+    (ok header rest)
+    (err errUnsupportedVersion rest)
+    (and?
+      (bytesEq? arborixMajorVersion (arborixHeaderMajorVersion header))
+      (bytesEq? arborixMinorVersion (arborixHeaderMinorVersion header))))
+
+readArborixContainer = (bs :
+  bindResult (readArborixHeader bs)
+    (header afterHeader :
+      bindResult (validateArborixHeader header afterHeader)
+        (validHeader afterValidHeader :
+          bindResult (readSectionDirectory
+            (u32BEBytesToNat (arborixHeaderSectionCount validHeader))
+            (bytesDrop (u64BEBytesToNat (arborixHeaderDirOffset validHeader)) bs))
+            (directory afterDirectory :
+              bindResult (validateSectionDirectory directory afterDirectory)
+                (validDirectory afterValidDirectory :
+                  ok (pair validHeader validDirectory) afterValidDirectory)))))
+
+sectionRecordOffsetNat = (sectionRecord :
+  u64BEBytesToNat (sectionRecordOffset sectionRecord))
+
+sectionRecordLengthNat = (sectionRecord :
+  u64BEBytesToNat (sectionRecordLength sectionRecord))
+
+extractSectionBytes = (sectionRecord containerBytes :
+  byteSlice
+    (sectionRecordOffsetNat sectionRecord)
+    (sectionRecordLengthNat sectionRecord)
+    containerBytes)
+
+extractSectionBytesResult = (sectionRecord containerBytes rest :
+  (sectionBytes :
+    matchBool
+      (ok sectionBytes rest)
+      (err errUnexpectedEof rest)
+      (equal? (bytesLength sectionBytes) (sectionRecordLengthNat sectionRecord)))
+    (extractSectionBytes sectionRecord containerBytes))
+
+lookupSectionBytes = (sectionId directory containerBytes :
+  triage
+    nothing
+    (sectionRecord : just (extractSectionBytes sectionRecord containerBytes))
+    (_ _ : nothing)
+    (lookupSectionRecord sectionId directory))
+
+sectionBytesOrErr = (sectionId directory containerBytes rest :
+  triage
+    (err errMissingSection rest)
+    (sectionRecord : extractSectionBytesResult sectionRecord containerBytes rest)
+    (_ _ : err errMissingSection rest)
+    (lookupSectionRecord sectionId directory))
+
+readArborixSectionBytes = (sectionId bs :
+  bindResult (readArborixContainer bs)
+    (container afterContainer :
+      matchPair
+        (_ directory : sectionBytesOrErr sectionId directory bs afterContainer)
+        container))
+
+readArborixRequiredSections = (bs :
+  bindResult (readArborixContainer bs)
+    (container afterContainer :
+      matchPair
+        (_ directory :
+          bindResult (sectionBytesOrErr arborixManifestSectionId directory bs afterContainer)
+            (manifestBytes _ :
+              bindResult (sectionBytesOrErr arborixNodesSectionId directory bs afterContainer)
+                (nodesBytes _ :
+                  ok (pair manifestBytes nodesBytes) afterContainer)))
+        container))
+
+readNodeRecord = (bs :
+  bindResult (readBytes 32 bs)
+    (nodeHash afterNodeHash :
+      bindResult (readBytes 4 afterNodeHash)
+        (payloadLength afterPayloadLength :
+          bindResult (readBytes (u32BEBytesToNat payloadLength) afterPayloadLength)
+            (payload afterPayload :
+              ok
+                (pair nodeHash
+                  (pair payloadLength payload))
+                afterPayload))))
+
+nodeRecordHash = (nodeRecord :
+  matchPair
+    (nodeHash _ : nodeHash)
+    nodeRecord)
+
+nodeRecordPayloadLength = (nodeRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (payloadLength _ : payloadLength)
+        payload)
+    nodeRecord)
+
+nodeRecordPayload = (nodeRecord :
+  matchPair
+    (_ payload :
+      matchPair
+        (_ nodePayload : nodePayload)
+        payload)
+    nodeRecord)
+
+nodePayloadKind = (nodePayload : bytesHead nodePayload)
+
+nodePayloadHasTag? = (tag nodePayload :
+  triage
+    false
+    (actualTag : byteEq? actualTag tag)
+    (_ _ : false)
+    (nodePayloadKind nodePayload))
+
+nodePayloadLeaf? = (nodePayload : bytesEq? [(0)] nodePayload)
+
+nodePayloadStem? = (nodePayload :
+  and?
+    (nodePayloadHasTag? nodePayloadStemTag nodePayload)
+    (equal? (bytesLength nodePayload) 33))
+
+nodePayloadFork? = (nodePayload :
+  and?
+    (nodePayloadHasTag? nodePayloadForkTag nodePayload)
+    (equal? (bytesLength nodePayload) 65))
+
+nodePayloadValid? = (nodePayload :
+  or?
+    (nodePayloadLeaf? nodePayload)
+    (or?
+      (nodePayloadStem? nodePayload)
+      (nodePayloadFork? nodePayload)))
+
+nodePayloadStemChildHash = (nodePayload : bytesTake 32 (bytesDrop 1 nodePayload))
+nodePayloadForkLeftHash = (nodePayload : bytesTake 32 (bytesDrop 1 nodePayload))
+nodePayloadForkRightHash = (nodePayload : bytesTake 32 (bytesDrop 33 nodePayload))
+
+nodeRecordPayloadValid? = (nodeRecord : nodePayloadValid? (nodeRecordPayload nodeRecord))
+
+nodeRecordsHaveInvalidPayload? = y (self nodeRecords :
+  matchList
+    false
+    (nodeRecord rest :
+      or?
+        (not? (nodeRecordPayloadValid? nodeRecord))
+        (self rest))
+    nodeRecords)
+
+nodeRecordsHaveHash? = y (self nodeRecords nodeHash :
+  matchList
+    false
+    (nodeRecord rest :
+      or?
+        (bytesEq? nodeHash (nodeRecordHash nodeRecord))
+        (self rest nodeHash))
+    nodeRecords)
+
+nodeRecordsHaveDuplicateHashes? = y (self nodeRecords :
+  matchList
+    false
+    (nodeRecord rest :
+      or?
+        (nodeRecordsHaveHash? rest (nodeRecordHash nodeRecord))
+        (self rest))
+    nodeRecords)
+
+lookupNodeRecord_ = y (self nodeRecords nodeHash :
+  matchList
+    nothing
+    (nodeRecord rest :
+      matchBool
+        (just nodeRecord)
+        (self rest nodeHash)
+        (bytesEq? nodeHash (nodeRecordHash nodeRecord)))
+    nodeRecords)
+
+lookupNodeRecord = (nodeHash nodeRecords : lookupNodeRecord_ nodeRecords nodeHash)
+
+nodeRecordChildHashes = (nodeRecord :
+  (nodePayload :
+    matchBool
+      t
+      (matchBool
+        (pair (nodePayloadStemChildHash nodePayload) t)
+        (pair (nodePayloadForkLeftHash nodePayload)
+          (pair (nodePayloadForkRightHash nodePayload) t))
+        (nodePayloadStem? nodePayload))
+      (nodePayloadLeaf? nodePayload))
+    (nodeRecordPayload nodeRecord))
+
+nodeHashPresent? = (nodeHash nodeRecords : nodeRecordsHaveHash? nodeRecords nodeHash)
+
+nodeChildHashesPresent? = y (self childHashes nodeRecords :
+  matchList
+    true
+    (childHash rest :
+      and?
+        (nodeHashPresent? childHash nodeRecords)
+        (self rest nodeRecords))
+    childHashes)
+
+nodeRecordChildrenPresent? = (nodeRecord nodeRecords :
+  nodeChildHashesPresent? (nodeRecordChildHashes nodeRecord) nodeRecords)
+
+nodeRecordsClosed? = y (self nodeRecords allNodeRecords :
+  matchList
+    true
+    (nodeRecord rest :
+      and?
+        (nodeRecordChildrenPresent? nodeRecord allNodeRecords)
+        (self rest allNodeRecords))
+    nodeRecords)
+
+validateNodeRecords = (nodeRecords rest :
+  matchBool
+    (err errInvalidNodePayload rest)
+    (matchBool
+      (err errDuplicateNode rest)
+      (matchBool
+        (ok nodeRecords rest)
+        (err errMissingNode rest)
+        (nodeRecordsClosed? nodeRecords nodeRecords))
+      (nodeRecordsHaveDuplicateHashes? nodeRecords))
+    (nodeRecordsHaveInvalidPayload? nodeRecords))
+
+readNodeRecords_ = y (self bs nodeCount i acc :
+  matchBool
+    (ok (reverse acc) bs)
+    (bindResult (readNodeRecord bs)
+      (nodeRecord afterNodeRecord :
+        self afterNodeRecord nodeCount (succ i) (pair nodeRecord acc)))
+    (equal? i nodeCount))
+
+readNodeRecords = (nodeCount bs : readNodeRecords_ bs nodeCount 0 t)
+
+readNodesSection = (bs :
+  bindResult (readBytes 8 bs)
+    (nodeCount afterNodeCount :
+      bindResult (readNodeRecords (u64BEBytesToNat nodeCount) afterNodeCount)
+        (nodeRecords afterNodeRecords :
+          bindResult (validateNodeRecords nodeRecords afterNodeRecords)
+            (validNodeRecords afterValidNodeRecords :
+              ok (pair nodeCount validNodeRecords) afterValidNodeRecords))))
+
+readNodesSectionComplete = (bs :
+  bindResult (readNodesSection bs)
+    (nodesSection afterNodesSection :
+      matchBool
+        (ok nodesSection afterNodesSection)
+        (err errUnexpectedBytes afterNodesSection)
+        (bytesNil? afterNodesSection)))
+
+readArborixNodesSection = (bs :
+  bindResult (readArborixContainer bs)
+    (container afterContainer :
+      matchPair
+        (_ directory :
+          bindResult (sectionBytesOrErr arborixNodesSectionId directory bs afterContainer)
+            (nodesBytes _ :
+              bindResult (readNodesSectionComplete nodesBytes)
+                (nodesSection _ : ok nodesSection afterContainer)))
+        container))
+
+nodesSectionCount = (nodesSection :
+  matchPair
+    (nodeCount _ : nodeCount)
+    nodesSection)
+
+nodesSectionRecords = (nodesSection :
+  matchPair
+    (_ nodeRecords : nodeRecords)
+    nodesSection)
+
+nodeRecordToTreeWith = (self nodeRecords nodeRecord :
+  (nodePayload :
+    matchBool
+      (ok t t)
+      (matchBool
+        (bindResult (self (nodePayloadStemChildHash nodePayload) nodeRecords)
+          (child _ : ok (t child) t))
+        (bindResult (self (nodePayloadForkLeftHash nodePayload) nodeRecords)
+          (left _ :
+            bindResult (self (nodePayloadForkRightHash nodePayload) nodeRecords)
+              (right _ : ok (pair left right) t)))
+        (nodePayloadStem? nodePayload))
+      (nodePayloadLeaf? nodePayload))
+    (nodeRecordPayload nodeRecord))
+
+nodeHashToTree = y (self nodeHash nodeRecords :
+  triage
+    (err errMissingNode t)
+    (nodeRecord : nodeRecordToTreeWith self nodeRecords nodeRecord)
+    (_ _ : err errMissingNode t)
+    (lookupNodeRecord nodeHash nodeRecords))
+
+readArborixTreeFromHash = (rootHash bs :
+  bindResult (readArborixNodesSection bs)
+    (nodesSection afterContainer :
+      bindResult (nodeHashToTree rootHash (nodesSectionRecords nodesSection))
+        (tree _ : ok tree afterContainer)))
+
+readArborixExecutableFromHash = readArborixTreeFromHash

lib/bytes.tri

@@ -14,27 +14,29 @@ byteEq? = equal?
 bytesLength = length
 bytesAppend = append
 
-bytesTake_ = y (self n i remaining :
+bytesTake_ = y (self remaining n i :
-  matchBool
+  matchList
     t
-    (matchList
+    (h r :
-      t
+      matchBool
-      (h r : pair h (self n (succ i) r))
+        t
-      remaining)
+        (pair h (self r n (succ i)))
-    (equal? i n))
+        (equal? i n))
+    remaining)
 
-bytesTake = n bytes : bytesTake_ n 0 bytes
+bytesTake = n bytes : bytesTake_ bytes n 0
 
-bytesDrop_ = y (self n i remaining :
+bytesDrop_ = y (self remaining n i :
-  matchBool
+  matchList
-    remaining
+    t
-    (matchList
+    (_ r :
-      t
+      matchBool
-      (_ r : self n (succ i) r)
+        remaining
-      remaining)
+        (self r n (succ i))
-    (equal? i n))
+        (equal? i n))
+    remaining)
 
-bytesDrop = n bytes : bytesDrop_ n 0 bytes
+bytesDrop = n bytes : bytesDrop_ bytes n 0
 
 bytesSplitAt = n bytes : pair (bytesTake n bytes) (bytesDrop n bytes)
 

lib/list.tri

@@ -27,11 +27,11 @@ filter_ = y (self : matchList
   (head tail f : matchBool (t head) id (f head) (self tail f)))
 filter  = f l : filter_ l f
 
-foldl_ = y (self f l x : matchList (acc : acc) (head tail acc : self f tail (f acc head)) l x)
+foldl_ = y (self l f x : matchList (acc : acc) (head tail acc : self tail f (f acc head)) l x)
-foldl  = f x l : foldl_ f l x
+foldl  = f x l : foldl_ l f x
 
-foldr_ = y (self x f l : matchList x (head tail : f (self x f tail) head) l)
+foldr_ = y (self l f x : matchList x (head tail : f (self tail f x) head) l)
-foldr  = f x l : foldr_ x f l
+foldr  = f x l : foldr_ l f x
 
 length = y (self : matchList
   0

test/Spec.hs

@@ -12,6 +12,7 @@ import ContentStore
 import Control.Exception      (evaluate, try, SomeException)
 import Control.Monad.IO.Class (liftIO)
 import Data.Bits              (xor)
+import Data.Char              (digitToInt)
 import Data.List              (isInfixOf)
 import Data.Text              (Text, unpack)
 import Data.Word              (Word8)
@@ -1051,6 +1052,104 @@ byteT = ofNumber
 bytesT :: [Integer] -> T
 bytesT = ofList . fmap byteT
 
+bytesExpr :: [Integer] -> String
+bytesExpr xs = "[" ++ unwords (map (\n -> "(" ++ show n ++ ")") xs) ++ "]"
+
+u16 :: Integer -> [Integer]
+u16 n = [0,n]
+
+u32 :: Integer -> [Integer]
+u32 n = [0,0,0,n]
+
+u64 :: Integer -> [Integer]
+u64 n = [0,0,0,0,0,0,0,n]
+
+arborixHeaderBytes :: Integer -> [Integer]
+arborixHeaderBytes sectionCount =
+  [65,82,66,79,82,73,88,0]
+  ++ u16 1
+  ++ u16 0
+  ++ u32 sectionCount
+  ++ u64 0
+  ++ u64 32
+
+sectionEntryBytes :: [Integer] -> Integer -> Integer -> [Integer]
+sectionEntryBytes sectionType offset lengthBytes =
+  sectionType
+  ++ u16 1
+  ++ u16 1
+  ++ u16 0
+  ++ u16 1
+  ++ u64 offset
+  ++ u64 lengthBytes
+  ++ replicate 32 0
+
+manifestSectionIdBytes :: [Integer]
+manifestSectionIdBytes = [0,0,0,1]
+
+nodesSectionIdBytes :: [Integer]
+nodesSectionIdBytes = [0,0,0,2]
+
+hexTextBytes :: Text -> [Integer]
+hexTextBytes h = go (unpack h)
+  where
+    go [] = []
+    go (a:b:rest) = toInteger (digitToInt a * 16 + digitToInt b) : go rest
+    go _ = error "odd-length hex text"
+
+manifestEntryBytes :: Integer -> Integer -> [Integer]
+manifestEntryBytes = sectionEntryBytes manifestSectionIdBytes
+
+nodesEntryBytes :: Integer -> Integer -> [Integer]
+nodesEntryBytes = sectionEntryBytes nodesSectionIdBytes
+
+simpleContainerBytes :: [Integer] -> [Integer] -> [Integer]
+simpleContainerBytes manifestBytes nodesBytes =
+  let manifestOffset = 152
+      nodesOffset = manifestOffset + fromIntegral (length manifestBytes)
+  in arborixHeaderBytes 2
+     ++ manifestEntryBytes manifestOffset (fromIntegral $ length manifestBytes)
+     ++ nodesEntryBytes nodesOffset (fromIntegral $ length nodesBytes)
+     ++ manifestBytes
+     ++ nodesBytes
+
+singleSectionContainerBytes :: [Integer] -> [Integer] -> [Integer]
+singleSectionContainerBytes sectionType sectionBytes =
+  arborixHeaderBytes 1
+  ++ sectionEntryBytes sectionType 92 (fromIntegral $ length sectionBytes)
+  ++ sectionBytes
+
+arborixHeaderT :: Integer -> T
+arborixHeaderT sectionCount =
+  pairT (bytesT [0,1])
+    (pairT (bytesT [0,0])
+      (pairT (bytesT $ u32 sectionCount)
+        (pairT (bytesT $ u64 0)
+          (bytesT $ u64 32))))
+
+sectionRecordT :: [Integer] -> Integer -> Integer -> T
+sectionRecordT sectionType offset lengthBytes =
+  pairT (bytesT sectionType)
+    (pairT (bytesT [0,1])
+      (pairT (bytesT [0,1])
+        (pairT (bytesT [0,0])
+          (pairT (bytesT [0,1])
+            (pairT (bytesT $ u64 offset)
+              (pairT (bytesT $ u64 lengthBytes)
+                (bytesT $ replicate 32 0)))))))
+
+sectionRecordExpr :: [Integer] -> Integer -> Integer -> String
+sectionRecordExpr sectionType offset lengthBytes =
+  "(pair " ++ bytesExpr sectionType
+  ++ " (pair " ++ bytesExpr [0,1]
+  ++ " (pair " ++ bytesExpr [0,1]
+  ++ " (pair " ++ bytesExpr [0,0]
+  ++ " (pair " ++ bytesExpr [0,1]
+  ++ " (pair " ++ bytesExpr (u64 offset)
+  ++ " (pair " ++ bytesExpr (u64 lengthBytes)
+  ++ " " ++ bytesExpr (replicate 32 0)
+  ++ ")))))))"
+
 byteListUtilities :: TestTree
 byteListUtilities = testGroup "Byte List Utility Tests"
   [ testCase "isNil: empty list is nil" $ do
@@ -1249,6 +1348,24 @@ unexpectedBytesT = byteT 2
 unexpectedByteT :: T
 unexpectedByteT = byteT 3
 
+missingSectionT :: T
+missingSectionT = byteT 4
+
+unsupportedVersionT :: T
+unsupportedVersionT = byteT 5
+
+duplicateSectionT :: T
+duplicateSectionT = byteT 6
+
+duplicateNodeT :: T
+duplicateNodeT = byteT 7
+
+invalidNodePayloadT :: T
+invalidNodePayloadT = byteT 8
+
+missingNodeT :: T
+missingNodeT = byteT 9
+
 binaryReaderTests :: TestTree
 binaryReaderTests = testGroup "Binary Reader Tests"
   [ testCase "readU8: empty input returns err" $ do
@@ -1523,25 +1640,17 @@ binaryReaderTests = testGroup "Binary Reader Tests"
   -- Arborix header parsing
   -- ------------------------------------------------------------------------
 
-  , testCase "readArborixHeader: parses version and section count" $ do
+  , testCase "readArborixHeader: parses portable header" $ do
-      let input = "readArborixHeader [(65) (82) (66) (79) (82) (73) (88) (0) (0) (1) (0) (0) (0) (0) (0) (0)]"
+      let input = "readArborixHeader " ++ bytesExpr (arborixHeaderBytes 0)
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= okT
+      result env @?= okT (arborixHeaderT 0) (bytesT [])
-        (pairT (bytesT [0,1])
-          (pairT (bytesT [0,0])
-            (bytesT [0,0,0,0])))
-        (bytesT [])
 
   , testCase "readArborixHeader: preserves trailing bytes" $ do
-      let input = "readArborixHeader [(65) (82) (66) (79) (82) (73) (88) (0) (0) (1) (0) (0) (0) (0) (0) (0) (9) (8)]"
+      let input = "readArborixHeader " ++ bytesExpr (arborixHeaderBytes 0 ++ [9,8])
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= okT
+      result env @?= okT (arborixHeaderT 0) (bytesT [9,8])
-        (pairT (bytesT [0,1])
-          (pairT (bytesT [0,0])
-            (bytesT [0,0,0,0])))
-        (bytesT [9,8])
 
   , testCase "readArborixHeader: rejects wrong magic preserving input" $ do
       let input = "readArborixHeader [(65) (82) (66) (79) (82) (73) (88) (1) (0) (1)]"
@@ -1559,25 +1668,17 @@ binaryReaderTests = testGroup "Binary Reader Tests"
   -- Arborix section directory record parsing
   -- ------------------------------------------------------------------------
 
-  , testCase "readSectionRecord: parses raw section id offset and length" $ do
+  , testCase "readSectionRecord: parses portable section entry" $ do
-      let input = "readSectionRecord [(0) (2) (0) (0) (0) (16) (0) (0) (0) (32)]"
+      let input = "readSectionRecord " ++ bytesExpr (nodesEntryBytes 16 32)
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= okT
+      result env @?= okT (sectionRecordT nodesSectionIdBytes 16 32) (bytesT [])
-        (pairT (bytesT [0,2])
-          (pairT (bytesT [0,0,0,16])
-            (bytesT [0,0,0,32])))
-        (bytesT [])
 
   , testCase "readSectionRecord: preserves trailing bytes" $ do
-      let input = "readSectionRecord [(0) (2) (0) (0) (0) (16) (0) (0) (0) (32) (9) (8)]"
+      let input = "readSectionRecord " ++ bytesExpr (nodesEntryBytes 16 32 ++ [9,8])
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= okT
+      result env @?= okT (sectionRecordT nodesSectionIdBytes 16 32) (bytesT [9,8])
-        (pairT (bytesT [0,2])
-          (pairT (bytesT [0,0,0,16])
-            (bytesT [0,0,0,32])))
-        (bytesT [9,8])
 
   , testCase "readSectionRecord: empty input returns EOF" $ do
       let input = "readSectionRecord []"
@@ -1591,17 +1692,17 @@ binaryReaderTests = testGroup "Binary Reader Tests"
       let env = evalTricu library (parseTricu input)
       result env @?= errT eofT (bytesT [0])
 
-  , testCase "readSectionRecord: missing offset returns EOF preserving unread offset bytes" $ do
+  , testCase "readSectionRecord: missing section version returns EOF preserving unread bytes" $ do
       let input = "readSectionRecord [(0) (2)]"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= errT eofT (bytesT [])
+      result env @?= errT eofT (bytesT [0,2])
 
-  , testCase "readSectionRecord: short offset returns EOF preserving unread offset bytes" $ do
+  , testCase "readSectionRecord: short section version returns EOF preserving unread bytes" $ do
       let input = "readSectionRecord [(0) (2) (0) (0) (0)]"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= errT eofT (bytesT [0,0,0])
+      result env @?= errT eofT (bytesT [0])
 
   , testCase "readSectionRecord: missing length returns EOF preserving unread length bytes" $ do
       let input = "readSectionRecord [(0) (2) (0) (0) (0) (16)]"
@@ -1609,11 +1710,11 @@ binaryReaderTests = testGroup "Binary Reader Tests"
       let env = evalTricu library (parseTricu input)
       result env @?= errT eofT (bytesT [])
 
-  , testCase "readSectionRecord: short length returns EOF preserving unread length bytes" $ do
+  , testCase "readSectionRecord: short section flags returns EOF preserving unread bytes" $ do
       let input = "readSectionRecord [(0) (2) (0) (0) (0) (16) (0) (0) (0)]"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= errT eofT (bytesT [0,0,0])
+      result env @?= errT eofT (bytesT [0])
 
   -- ------------------------------------------------------------------------
   -- Arborix section directory parsing
@@ -1626,17 +1727,13 @@ binaryReaderTests = testGroup "Binary Reader Tests"
       result env @?= okT (ofList []) (bytesT [9,8])
 
   , testCase "readSectionDirectory: reads requested records and preserves trailing bytes" $ do
-      let input = "readSectionDirectory 2 [(0) (1) (0) (0) (0) (10) (0) (0) (0) (20) (0) (2) (0) (0) (0) (30) (0) (0) (0) (40) (9)]"
+      let input = "readSectionDirectory 2 " ++ bytesExpr (manifestEntryBytes 10 20 ++ nodesEntryBytes 30 40 ++ [9])
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
       result env @?= okT
         (ofList
-          [ pairT (bytesT [0,1])
+          [ sectionRecordT manifestSectionIdBytes 10 20
-              (pairT (bytesT [0,0,0,10])
+          , sectionRecordT nodesSectionIdBytes 30 40
-                (bytesT [0,0,0,20]))
-          , pairT (bytesT [0,2])
-              (pairT (bytesT [0,0,0,30])
-                (bytesT [0,0,0,40]))
           ])
         (bytesT [9])
 
@@ -1651,16 +1748,13 @@ binaryReaderTests = testGroup "Binary Reader Tests"
   -- ------------------------------------------------------------------------
 
   , testCase "lookupSectionRecord: finds record by raw section id" $ do
-      let input = "lookupSectionRecord [(0) (2)] [(pair [(0) (1)] (pair [(0) (0) (0) (10)] [(0) (0) (0) (20)])) (pair [(0) (2)] (pair [(0) (0) (0) (30)] [(0) (0) (0) (40)]))]"
+      let input = "lookupSectionRecord " ++ bytesExpr nodesSectionIdBytes ++ " [(" ++ "pair " ++ bytesExpr manifestSectionIdBytes ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,0] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr (u64 10) ++ " (pair " ++ bytesExpr (u64 20) ++ " " ++ bytesExpr (replicate 32 0) ++ "))))))" ++ ") (" ++ "pair " ++ bytesExpr nodesSectionIdBytes ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,0] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr (u64 30) ++ " (pair " ++ bytesExpr (u64 40) ++ " " ++ bytesExpr (replicate 32 0) ++ "))))))" ++ ")]"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
-      result env @?= justT
+      result env @?= justT (sectionRecordT nodesSectionIdBytes 30 40)
-        (pairT (bytesT [0,2])
-          (pairT (bytesT [0,0,0,30])
-            (bytesT [0,0,0,40])))
 
   , testCase "lookupSectionRecord: missing section id returns nothing" $ do
-      let input = "lookupSectionRecord [(0) (3)] [(pair [(0) (1)] (pair [(0) (0) (0) (10)] [(0) (0) (0) (20)])) (pair [(0) (2)] (pair [(0) (0) (0) (30)] [(0) (0) (0) (40)]))]"
+      let input = "lookupSectionRecord " ++ bytesExpr [0,0,0,3] ++ " [(" ++ "pair " ++ bytesExpr manifestSectionIdBytes ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,0] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr (u64 10) ++ " (pair " ++ bytesExpr (u64 20) ++ " " ++ bytesExpr (replicate 32 0) ++ "))))))" ++ ") (" ++ "pair " ++ bytesExpr nodesSectionIdBytes ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr [0,0] ++ " (pair " ++ bytesExpr [0,1] ++ " (pair " ++ bytesExpr (u64 30) ++ " (pair " ++ bytesExpr (u64 40) ++ " " ++ bytesExpr (replicate 32 0) ++ "))))))" ++ ")]"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
       result env @?= nothingT
@@ -1676,4 +1770,421 @@ binaryReaderTests = testGroup "Binary Reader Tests"
       library <- evaluateFile "./lib/arborix.tri"
       let env = evalTricu library (parseTricu input)
       result env @?= bytesT [14,15]
+
+  -- ------------------------------------------------------------------------
+  -- Arborix minimal container parsing foundation
+  -- ------------------------------------------------------------------------
+
+  , testCase "u32BEBytesToNat: decodes zero" $ do
+      let input = "u32BEBytesToNat [(0) (0) (0) (0)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofNumber 0
+
+  , testCase "u32BEBytesToNat: decodes small section count" $ do
+      let input = "u32BEBytesToNat [(0) (0) (0) (2)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofNumber 2
+
+  , testCase "u64BEBytesToNat: decodes small node count" $ do
+      let input = "u64BEBytesToNat [(0) (0) (0) (0) (0) (0) (0) (2)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofNumber 2
+
+  , testCase "u64BEBytesToNat: decodes fixture-scale offset" $ do
+      let input = "u64BEBytesToNat [(0) (0) (0) (0) (0) (0) (3) (214)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofNumber 982
+
+  , testCase "readArborixContainer: reads header directory and preserves payload" $ do
+      let input = "readArborixContainer " ++ bytesExpr (simpleContainerBytes [101,102,103] [201,202,203,204])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT
+        (pairT
+          (arborixHeaderT 2)
+          (ofList
+            [ sectionRecordT manifestSectionIdBytes 152 3
+            , sectionRecordT nodesSectionIdBytes 155 4
+            ]))
+        (bytesT [101,102,103,201,202,203,204])
+
+  , testCase "readArborixContainer: truncated directory returns EOF" $ do
+      let input = "readArborixContainer " ++ bytesExpr (arborixHeaderBytes 1 ++ [0,0])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT eofT (bytesT [0,0])
+
+  , testCase "readArborixContainer: rejects unsupported major version" $ do
+      let badHeader = [65,82,66,79,82,73,88,0] ++ u16 2 ++ u16 0 ++ u32 0 ++ u64 0 ++ u64 32
+          input = "readArborixContainer " ++ bytesExpr badHeader
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT unsupportedVersionT (bytesT [])
+
+  , testCase "readArborixContainer: rejects unsupported minor version" $ do
+      let badHeader = [65,82,66,79,82,73,88,0] ++ u16 1 ++ u16 1 ++ u32 0 ++ u64 0 ++ u64 32
+          input = "readArborixContainer " ++ bytesExpr badHeader
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT unsupportedVersionT (bytesT [])
+
+  , testCase "readArborixContainer: rejects duplicate section ids" $ do
+      let input = "readArborixContainer " ++ bytesExpr (arborixHeaderBytes 2 ++ manifestEntryBytes 152 1 ++ manifestEntryBytes 153 1 ++ [9])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT duplicateSectionT (bytesT [9])
+
+  , testCase "extractSectionBytes: uses raw offset and length fields" $ do
+      let input = "extractSectionBytes " ++ sectionRecordExpr nodesSectionIdBytes 3 4 ++ " " ++ bytesExpr [10,11,12,13,14,15,16,17]
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= bytesT [13,14,15,16]
+
+  , testCase "lookupSectionBytes: finds section and extracts raw bytes" $ do
+      let input = "lookupSectionBytes " ++ bytesExpr nodesSectionIdBytes ++ " [" ++ sectionRecordExpr manifestSectionIdBytes 1 2 ++ " " ++ sectionRecordExpr nodesSectionIdBytes 4 3 ++ "] " ++ bytesExpr [10,11,12,13,14,15,16,17]
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= justT (bytesT [14,15,16])
+
+  , testCase "lookupSectionBytes: missing section returns nothing" $ do
+      let input = "lookupSectionBytes " ++ bytesExpr [0,0,0,3] ++ " [" ++ sectionRecordExpr manifestSectionIdBytes 1 2 ++ " " ++ sectionRecordExpr nodesSectionIdBytes 4 3 ++ "] " ++ bytesExpr [10,11,12,13,14,15,16,17]
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= nothingT
+
+  , testCase "extractSectionBytesResult: rejects out-of-bounds section" $ do
+      let input = "extractSectionBytesResult " ++ sectionRecordExpr nodesSectionIdBytes 6 4 ++ " " ++ bytesExpr [10,11,12,13,14,15,16,17] ++ " []"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT eofT (bytesT [])
+
+  , testCase "readArborixSectionBytes: extracts requested section from container" $ do
+      let input = "readArborixSectionBytes " ++ bytesExpr nodesSectionIdBytes ++ " " ++ bytesExpr (simpleContainerBytes [101,102,103] [201,202,203,204])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (bytesT [201,202,203,204]) (bytesT [101,102,103,201,202,203,204])
+
+  , testCase "readArborixSectionBytes: missing section returns missing-section err" $ do
+      let input = "readArborixSectionBytes " ++ bytesExpr nodesSectionIdBytes ++ " " ++ bytesExpr (singleSectionContainerBytes manifestSectionIdBytes [101,102,103])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT missingSectionT (bytesT [101,102,103])
+
+  , testCase "readArborixRequiredSections: extracts manifest and nodes bytes" $ do
+      let input = "readArborixRequiredSections " ++ bytesExpr (simpleContainerBytes [101,102,103] [201,202,203,204])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT
+        (pairT (bytesT [101,102,103]) (bytesT [201,202,203,204]))
+        (bytesT [101,102,103,201,202,203,204])
+
+  , testCase "readArborixRequiredSections: missing nodes section returns missing-section err" $ do
+      let input = "readArborixRequiredSections " ++ bytesExpr (singleSectionContainerBytes manifestSectionIdBytes [101,102,103])
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT missingSectionT (bytesT [101,102,103])
+
+  , testCase "readArborixRequiredSections: out-of-bounds section returns EOF" $ do
+      let manifestBytes = [101,102,103]
+          nodesBytes = [201,202,203,204]
+          badContainer = arborixHeaderBytes 2 ++ manifestEntryBytes 152 3 ++ nodesEntryBytes 155 9 ++ manifestBytes ++ nodesBytes
+          input = "readArborixRequiredSections " ++ bytesExpr badContainer
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT eofT (bytesT [101,102,103,201,202,203,204])
+
+  -- ------------------------------------------------------------------------
+  -- Arborix raw nodes section parsing
+  -- ------------------------------------------------------------------------
+
+  , testCase "readNodeRecord: parses hash length and raw payload" $ do
+      let input = "readNodeRecord [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (3) (101) (102) (103) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT
+        (pairT (bytesT [1..32])
+          (pairT (bytesT [0,0,0,3])
+            (bytesT [101,102,103])))
+        (bytesT [9])
+
+  , testCase "readNodeRecord: truncated payload returns EOF preserving unread payload" $ do
+      let input = "readNodeRecord [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (3) (101) (102)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT eofT (bytesT [101,102])
+
+  , testCase "readNodesSection: parses node count and records" $ do
+      let input = "readNodesSection [(0) (0) (0) (0) (0) (0) (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (1) (0) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT
+        (pairT (bytesT [0,0,0,0,0,0,0,1])
+          (ofList
+            [ pairT (bytesT [1..32])
+                (pairT (bytesT [0,0,0,1])
+                  (bytesT [0]))
+            ]))
+        (bytesT [9])
+
+  , testCase "readNodesSectionComplete: rejects trailing bytes inside nodes section" $ do
+      let input = "readNodesSectionComplete [(0) (0) (0) (0) (0) (0) (0) (0) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT unexpectedBytesT (bytesT [9])
+
+  , testCase "readNodesSection: rejects duplicate node hashes" $ do
+      let input = "readNodesSection [(0) (0) (0) (0) (0) (0) (0) (2) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (1) (0) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (1) (0) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT duplicateNodeT (bytesT [9])
+
+  , testCase "nodePayloadValid?: accepts leaf stem and fork payload shapes" $ do
+      let input = "[(nodePayloadValid? [(0)]) (nodePayloadValid? [(1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)]) (nodePayloadValid? [(2) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)])]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofList [trueT, trueT, trueT]
+
+  , testCase "nodePayloadValid?: rejects invalid payload shapes" $ do
+      let input = "[(nodePayloadValid? []) (nodePayloadValid? [(9)]) (nodePayloadValid? [(1) (1)]) (nodePayloadValid? [(2) (1) (2)])]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofList [falseT, falseT, falseT, falseT]
+
+  , testCase "node payload child accessors expose raw hashes" $ do
+      let input = "[(nodePayloadStemChildHash [(1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)]) (nodePayloadForkLeftHash [(2) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)]) (nodePayloadForkRightHash [(2) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)])]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofList [bytesT [1..32], bytesT [1..32], bytesT [33..64]]
+
+  , testCase "lookupNodeRecord: finds record by raw node hash" $ do
+      let input = "lookupNodeRecord [(33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)] [(pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (1)] [(0)])) (pair [(33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)] (pair [(0) (0) (0) (1)] [(0)]))]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= justT
+        (pairT (bytesT [33..64])
+          (pairT (bytesT [0,0,0,1])
+            (bytesT [0])))
+
+  , testCase "nodeRecordChildHashes: extracts stem and fork references" $ do
+      let input = "[(nodeRecordChildHashes (pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (33)] [(1) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)]))) (nodeRecordChildHashes (pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (65)] [(2) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64) (65) (66) (67) (68) (69) (70) (71) (72) (73) (74) (75) (76) (77) (78) (79) (80) (81) (82) (83) (84) (85) (86) (87) (88) (89) (90) (91) (92) (93) (94) (95) (96)])))]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= ofList
+        [ ofList [bytesT [33..64]]
+        , ofList [bytesT [33..64], bytesT [65..96]]
+        ]
+
+  , testCase "readNodesSection: rejects invalid node payload shape" $ do
+      let input = "readNodesSection [(0) (0) (0) (0) (0) (0) (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (1) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT invalidNodePayloadT (bytesT [])
+
+  , testCase "readNodesSection: rejects missing child node" $ do
+      let input = "readNodesSection [(0) (0) (0) (0) (0) (0) (0) (1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (0) (0) (0) (33) (1) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64) (9)]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= errT missingNodeT (bytesT [9])
+
+  , testCase "readArborixNodesSection: extracts and parses raw nodes section" $ do
+      let nodesBytes = u64 1 ++ [1..32] ++ u32 1 ++ [0]
+          input = "readArborixNodesSection " ++ bytesExpr (simpleContainerBytes [101,102,103] nodesBytes)
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT
+        (pairT (bytesT [0,0,0,0,0,0,0,1])
+          (ofList
+            [ pairT (bytesT [1..32])
+                (pairT (bytesT [0,0,0,1])
+                  (bytesT [0]))
+            ]))
+        (bytesT ([101,102,103] ++ nodesBytes))
+
+  -- ------------------------------------------------------------------------
+  -- Arborix node DAG reconstruction
+  -- ------------------------------------------------------------------------
+
+  , testCase "nodeHashToTree: reconstructs leaf node" $ do
+      let input = "nodeHashToTree [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] [(pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (1)] [(0)]))]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT Leaf Leaf
+
+  , testCase "nodeHashToTree: reconstructs stem node" $ do
+      let input = "nodeHashToTree [(33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)] [(pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (1)] [(0)])) (pair [(33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)] (pair [(0) (0) (0) (33)] [(1) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)]))]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (Stem Leaf) Leaf
+
+  , testCase "nodeHashToTree: reconstructs fork node" $ do
+      let input = "nodeHashToTree [(65) (66) (67) (68) (69) (70) (71) (72) (73) (74) (75) (76) (77) (78) (79) (80) (81) (82) (83) (84) (85) (86) (87) (88) (89) (90) (91) (92) (93) (94) (95) (96)] [(pair [(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32)] (pair [(0) (0) (0) (1)] [(0)])) (pair [(33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)] (pair [(0) (0) (0) (1)] [(0)])) (pair [(65) (66) (67) (68) (69) (70) (71) (72) (73) (74) (75) (76) (77) (78) (79) (80) (81) (82) (83) (84) (85) (86) (87) (88) (89) (90) (91) (92) (93) (94) (95) (96)] (pair [(0) (0) (0) (65)] [(2) (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47) (48) (49) (50) (51) (52) (53) (54) (55) (56) (57) (58) (59) (60) (61) (62) (63) (64)]))]"
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (Fork Leaf Leaf) Leaf
+
+  , testCase "readArborixTreeFromHash: reconstructs tree from bundle bytes" $ do
+      let nodesBytes = u64 1 ++ [1..32] ++ u32 1 ++ [0]
+          input = "readArborixTreeFromHash " ++ bytesExpr [1..32] ++ " " ++ bytesExpr (simpleContainerBytes [101,102,103] nodesBytes)
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT Leaf (bytesT ([101,102,103] ++ nodesBytes))
+
+  , testCase "readArborixExecutableFromHash: alias reconstructs tree" $ do
+      let nodesBytes = u64 1 ++ [1..32] ++ u32 1 ++ [0]
+          input = "readArborixExecutableFromHash " ++ bytesExpr [1..32] ++ " " ++ bytesExpr (simpleContainerBytes [101,102,103] nodesBytes)
+      library <- evaluateFile "./lib/arborix.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT Leaf (bytesT ([101,102,103] ++ nodesBytes))
+
+  , testCase "readArborixNodesSection: reads id fixture bundle" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/id.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right _ -> do
+          let input = "matchResult (code rest : code) (nodes rest : 0) (readArborixNodesSection "
+                ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                ++ ")"
+          library <- evaluateFile "./lib/arborix.tri"
+          let env = evalTricu library (parseTricu input)
+          result env @?= ofNumber 0
+
+  , testCase "readArborixNodesSection: reads notQ fixture bundle" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/notQ.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right _ -> do
+          let input = "matchResult (code rest : code) (nodes rest : 0) (readArborixNodesSection "
+                ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                ++ ")"
+          library <- evaluateFile "./lib/arborix.tri"
+          let env = evalTricu library (parseTricu input)
+          result env @?= ofNumber 0
+
+  , testCase "readArborixNodesSection: reads map fixture bundle" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/map.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right _ -> do
+          let input = "matchResult (code rest : code) (nodes rest : 0) (readArborixNodesSection "
+                ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                ++ ")"
+          library <- evaluateFile "./lib/arborix.tri"
+          let env = evalTricu library (parseTricu input)
+          result env @?= ofNumber 0
+
+  , testCase "readArborixExecutableFromHash: reconstructs id fixture root" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/id.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : 0) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= ofNumber 0
+
+  , testCase "readArborixExecutableFromHash: reconstructs notQ fixture root" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/notQ.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : 0) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= ofNumber 0
+
+  , testCase "readArborixExecutableFromHash: reconstructs map fixture root" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/map.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : 0) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= ofNumber 0
+
+  , testCase "readArborixExecutableFromHash: executes id fixture root" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/id.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : tree 42) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= ofNumber 42
+
+  , testCase "readArborixExecutableFromHash: executes notQ fixture on true" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/notQ.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : tree true) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= falseT
+
+  , testCase "readArborixExecutableFromHash: executes notQ fixture on false" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/notQ.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : tree false) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= trueT
+
+  , testCase "readArborixExecutableFromHash: executes map fixture root" $ do
+      fixtureBytes <- BS.readFile "test/fixtures/map.tri.bundle"
+      case decodeBundle fixtureBytes of
+        Left err -> assertFailure $ "decodeBundle failed: " ++ err
+        Right bundle -> case bundleRoots bundle of
+          [] -> assertFailure "fixture has no roots"
+          (rootHash:_) -> do
+            let input = "matchResult (code rest : code) (tree rest : head (tail (tree (a : (t t t)) [(t) (t) (t)]))) (readArborixExecutableFromHash "
+                  ++ bytesExpr (hexTextBytes rootHash)
+                  ++ " "
+                  ++ bytesExpr (map toInteger $ BS.unpack fixtureBytes)
+                  ++ ")"
+            library <- evaluateFile "./lib/arborix.tri"
+            let env = evalTricu library (parseTricu input)
+            result env @?= Fork Leaf Leaf
   ]

test/fixtures/notQ.tri

@@ -1,2 +0,0 @@
-\!import "base.tri" _
-main = not?