Move merkleRoot() into its own module

poseidon2.nim

@@ -1,47 +1,12 @@
-import std/sequtils
-import constantine/math/arithmetic
-
 import poseidon2/types
-import poseidon2/permutation
 import poseidon2/io
 import poseidon2/sponge
 import poseidon2/compress
+import poseidon2/merkle
 
 export sponge
 export compress
+export merkle
 export toBytes
 export elements
 export types
-
-#-------------------------------------------------------------------------------
-
-func merkleRoot*(xs: openArray[F]) : F =
-  let a = low(xs)
-  let b = high(xs)
-  let m = b-a+1
-
-  if m==1:
-    return xs[a]
-
-  else:
-    let halfn  : int  = m div 2
-    let n      : int  = 2*halfn
-    let isOdd : bool = (n != m)
-
-    var ys : seq[F]
-    if not isOdd:
-      ys = newSeq[F](halfn)
-    else:
-      ys = newSeq[F](halfn+1)
-
-    for i in 0..<halfn:
-      ys[i] = compress( xs[a+2*i], xs[a+2*i+1] )
-    if isOdd:
-      ys[halfn] = compress( xs[n], zero )
-
-    return merkleRoot(ys)
-
-func merkleRoot*(bytes: openArray[byte]): F =
-  merkleRoot(toSeq bytes.elements(F))
-
-#-------------------------------------------------------------------------------

poseidon2/merkle.nim

@@ -0,0 +1,34 @@
+import std/sequtils
+import constantine/math/arithmetic
+import ./types
+import ./io
+import ./compress
+
+func merkleRoot*(xs: openArray[F]) : F =
+  let a = low(xs)
+  let b = high(xs)
+  let m = b-a+1
+
+  if m==1:
+    return xs[a]
+
+  else:
+    let halfn  : int  = m div 2
+    let n      : int  = 2*halfn
+    let isOdd : bool = (n != m)
+
+    var ys : seq[F]
+    if not isOdd:
+      ys = newSeq[F](halfn)
+    else:
+      ys = newSeq[F](halfn+1)
+
+    for i in 0..<halfn:
+      ys[i] = compress( xs[a+2*i], xs[a+2*i+1] )
+    if isOdd:
+      ys[halfn] = compress( xs[n], zero )
+
+    return merkleRoot(ys)
+
+func merkleRoot*(bytes: openArray[byte]): F =
+  merkleRoot(toSeq bytes.elements(F))

tests/poseidon2/testMerkle.nim

@@ -8,9 +8,11 @@ import constantine/math/io/io_bigints
 import constantine/serialization/codecs
 
 import poseidon2/types
-import poseidon2
+import poseidon2/io
+import poseidon2/compress
+import poseidon2/merkle
 
-suite "poseidon2":
+suite "merkle root":
 
   test "merkle root of field elements":
     let m = 17

tests/test.nim

@@ -1,7 +1,7 @@
 import ./poseidon2/testPermutation
 import ./poseidon2/testSponge
 import ./poseidon2/testCompress
-import ./poseidon2/testPoseidon2
+import ./poseidon2/testMerkle
 import ./poseidon2/testIo
 import ./poseidon2/testReadme