use the new status-im/ranges library

.gitignore

@@ -1,6 +1,7 @@
-nimcache/
-
 # ignore all executable files
 *
 !*.*
 !*/
+
+nimcache/
+

rlp.nim

@@ -315,6 +315,9 @@ template decode*(bytes: openarray[byte], T: typedesc): T =
   var bytesCopy = @bytes
   decode(initBytesRange(bytesCopy), T)
 
+proc append*(writer: var RlpWriter; rlp: Rlp) =
+  append(writer, rlp.rawData)
+
 proc inspectAux(self: var Rlp, depth: int, output: var string) =
   if not hasData():
     return

rlp.nimble

@@ -1,13 +1,13 @@
 mode = ScriptMode.Verbose
 
 packageName   = "rlp"
-version       = "1.0.0"
+version       = "1.0.1"
 author        = "Status Research & Development GmbH"
 description   = "RLP serialization library for Nim"
 license       = "Apache2"
 skipDirs      = @["tests"]
 
-requires "nim >= 0.17.0"
+requires "nim >= 0.17.0", "ranges >= 0.0.1"
 
 proc configForTests() =
   --hints: off

rlp/ptr_arith.nim

@@ -1,5 +0,0 @@
-proc baseAddr*[T](x: openarray[T]): pointer = cast[pointer](x)
-
-proc shift*(p: pointer, delta: int): pointer =
-  cast[pointer](cast[int](p) + delta)
-

rlp/types.nim

@@ -1,3 +1,6 @@
+import
+  ranges/ptr_arith
+
 type
   Bytes* = seq[byte]
   
@@ -45,13 +48,21 @@ iterator items*(r: BytesRange): byte =
   for i in r.ibegin ..< r.iend:
     yield r.bytes[i]
 
-converter fromSeq*(s: Bytes): BytesRange =
+proc toRange*(s: Bytes): BytesRange =
   var seqCopy = s
   return initBytesRange(seqCopy)
 
-converter fromVarSeq*(s: var Bytes): BytesRange =
+proc toRange*(s: var Bytes): BytesRange =
   return initBytesRange(s)
 
+# XXX: This could be a template once the following issue is fixed:
+# https://github.com/nim-lang/Nim/issues/7223
+proc rangeBeginAddr*(r: BytesRange): pointer {.inline.} =
+  baseAddr(r.bytes).shift(r.ibegin)
+
+proc baseAddr*(r: BytesRange): pointer =
+  baseAddr(r.bytes).shift(r.ibegin)
+
 when false:
   import
     ptr_arith, keccak_tiny

rlp/writer.nim

@@ -1,5 +1,10 @@
 import
-  types, ptr_arith, object_serialization, priv/defs, macros
+  macros, types,
+  ranges/[memranges, ptr_arith],
+  object_serialization, priv/defs
+
+export
+  memranges
 
 type
   RlpWriter* = object
@@ -119,14 +124,18 @@ proc startList(self; listSize: int) =
     pendingLists.add((listSize, output.len))
 
 template appendImpl(self; data, startMarker) =
+  mixin baseAddr
+
   if data.len == 1 and byte(data[0]) < BLOB_START_MARKER:
-    output.add byte(data[0])
+    self.output.add byte(data[0])
   else:
-    output.writeCount(data.len, startMarker)
+    self.output.writeCount(data.len, startMarker)
 
     let startPos = output.len
-    output.setLen(startPos + data.len)
+    self.output.setLen(startPos + data.len)
-    copyMem(output.baseAddr.shift(startPos), data.baseAddr, data.len)
+    copyMem(shift(baseAddr(self.output), startPos),
+            baseAddr(data),
+            data.len)
 
   maybeClosePendingLists()
 
@@ -136,6 +145,12 @@ proc append*(self; data: string) =
 proc append*(self; data: Bytes) =
   appendImpl(self, data, BLOB_START_MARKER)
 
+proc append*(self; data: BytesRange) =
+  appendImpl(self, data, BLOB_START_MARKER)
+
+proc append*(self; data: MemRange) =
+  appendImpl(self, data, BLOB_START_MARKER)
+
 proc append*(self; i: Integer) =
   if i == 0:
     self.output.add BLOB_START_MARKER
@@ -186,12 +201,12 @@ macro encodeList*(args: varargs[untyped]): BytesRange =
 
   for arg in args:
     body.add quote do:
-      `writer`.append(`arg`)
+      append(`writer`, `arg`)
 
   result = quote do:
     var `writer` = initRlpList(`listLen`)
     `body`
-    `writer`.finish()
+    finish(`writer`)
 
 when false:
   # XXX: Currently fails with a malformed AST error on the args.len expression

tests/test_api_usage.nim

@@ -7,7 +7,7 @@ proc i(s: string): string = s.replace(" ").replace("\n")
 proc inspectMatch(r: Rlp, s: string): bool = r.inspect.i == s.i
 
 test "empty bytes are not a proper RLP":
-  var rlp = rlpFromBytes Bytes(@[])
+  var rlp = rlpFromBytes Bytes(@[]).toRange
 
   check:
     not rlp.hasData