Simplify encoding of tuples

Readme.md

@@ -32,13 +32,7 @@ AbiEncoder.encode([1'u8, 2'u8, 3'u8])
 AbiEncoder.encode(@[1'u8, 2'u8, 3'u8])
 
 # encode tuples
-var encoder = AbiEncoder.init()
-encoder.startTuple()
-encoder.write(42'u8)
-encoder.write(@[1'u8, 2'u8, 3'u8])
-encoder.write(true)
-encoder.finishTuple()
-encoder.finish()
+AbiEncoder.encode( (42'u8, @[1'u8, 2'u8, 3'u8], true) )
 ```
 
 [1]: https://docs.soliditylang.org/en/latest/abi-spec.html

contractabi/encoding.nim

@@ -54,7 +54,7 @@ func postpone(encoder: var AbiEncoder, bytes: seq[byte]) =
 func setDynamic(encoder: var AbiEncoder) =
   encoder.stack[^1].dynamic = true
 
-func startTuple*(encoder: var AbiEncoder) =
+func startTuple(encoder: var AbiEncoder) =
   encoder.stack.add(Tuple())
 
 func encode(encoder: var AbiEncoder, tupl: Tuple) =
@@ -64,7 +64,7 @@ func encode(encoder: var AbiEncoder, tupl: Tuple) =
   else:
     encoder.append(tupl.finish())
 
-func finishTuple*(encoder: var AbiEncoder) =
+func finishTuple(encoder: var AbiEncoder) =
   encoder.encode(encoder.stack.pop())
 
 func pad(encoder: var AbiEncoder, len: int) =
@@ -114,6 +114,12 @@ func encode[T](encoder: var AbiEncoder, value: seq[T]) =
 func encode(encoder: var AbiEncoder, value: string) =
   encoder.encode(value.toBytes)
 
+func encode(encoder: var AbiEncoder, tupl: tuple) =
+  encoder.startTuple()
+  for element in tupl.fields:
+    encoder.write(element)
+  encoder.finishTuple()
+
 func write*[T](encoder: var AbiEncoder, value: T) =
   var writer = AbiEncoder.init()
   writer.encode(value)

tests/contractabi/testDecoding.nim

@@ -68,15 +68,7 @@ suite "ABI decoding":
     let b = @[1'u8, 2'u8, 3'u8]
     let c = 0xAABBCCDD'u32
     let d = @[4'u8, 5'u8, 6'u8]
-
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.write(b)
-    encoder.write(c)
-    encoder.write(d)
-    encoder.finishTuple()
-    let encoding = encoder.finish()
+    let encoding = AbiEncoder.encode( (a, b, c, d) )
 
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=true)
@@ -93,17 +85,7 @@ suite "ABI decoding":
     let c = 0xAABBCCDD'u32
     let d = @[4'u8, 5'u8, 6'u8]
 
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.write(b)
-    encoder.startTuple()
-    encoder.write(c)
-    encoder.write(d)
-    encoder.finishTuple()
-    encoder.finishTuple()
-    let encoding = encoder.finish()
-
+    let encoding = AbiEncoder.encode( (a, b, (c, d)) )
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=true)
     check decoder.read(bool) == a
@@ -118,49 +100,35 @@ suite "ABI decoding":
   test "reads elements after dynamic tuple":
     let a = @[1'u8, 2'u8, 3'u8]
     let b = 0xAABBCCDD'u32
-    var encoder = AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.finishTuple()
-    encoder.write(b)
-    let encoding = encoder.finish()
+    let encoding = AbiEncoder.encode( ((a,), b) )
 
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=true)
+    decoder.startTuple(dynamic=true)
     check decoder.read(seq[byte]) == a
     decoder.finishTuple()
     check decoder.read(uint32) == b
+    decoder.finishTuple()
     decoder.finish()
 
   test "reads elements after static tuple":
     let a = 0x123'u16
     let b = 0xAABBCCDD'u32
-    var encoder = AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.finishTuple()
-    encoder.write(b)
-    let encoding = encoder.finish()
+    let encoding = AbiEncoder.encode( ((a,), b) )
 
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=false)
+    decoder.startTuple(dynamic=false)
     check decoder.read(uint16) == a
     decoder.finishTuple()
     check decoder.read(uint32) == b
+    decoder.finishTuple()
     decoder.finish()
 
   test "reads static tuple inside dynamic tuple":
     let a = @[1'u8, 2'u8, 3'u8]
     let b = 0xAABBCCDD'u32
-
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.startTuple()
-    encoder.write(b)
-    encoder.finishTuple()
-    encoder.finishTuple()
-    let encoding = encoder.finish()
+    let encoding = AbiEncoder.encode( (a, (b,)) )
 
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=true)
@@ -172,12 +140,7 @@ suite "ABI decoding":
     decoder.finish()
 
   test "reads empty tuples":
-    var encoder = AbiEncoder.init()
-    encoder.startTuple()
-    encoder.startTuple()
-    encoder.finishTuple()
-    encoder.finishTuple()
-    let encoding = encoder.finish()
+    let encoding = AbiEncoder.encode( ((),) )
 
     var decoder = AbiDecoder.init(encoding)
     decoder.startTuple(dynamic=false)

tests/contractabi/testEncoding.nim

@@ -68,14 +68,7 @@ suite "ABI encoding":
     let b = @[1'u8, 2'u8, 3'u8]
     let c = 0xAABBCCDD'u32
     let d = @[4'u8, 5'u8, 6'u8]
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.write(b)
-    encoder.write(c)
-    encoder.write(d)
-    encoder.finishTuple()
-    check encoder.finish() ==
+    check AbiEncoder.encode( (a, b, c, d) ) ==
       AbiEncoder.encode(a) &
       AbiEncoder.encode(4 * 32'u8) & # offset in tuple
       AbiEncoder.encode(c) &
@@ -88,16 +81,7 @@ suite "ABI encoding":
     let b = @[1'u8, 2'u8, 3'u8]
     let c = 0xAABBCCDD'u32
     let d = @[4'u8, 5'u8, 6'u8]
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.write(b)
-    encoder.startTuple()
-    encoder.write(c)
-    encoder.write(d)
-    encoder.finishTuple()
-    encoder.finishTuple()
-    check encoder.finish() ==
+    check AbiEncoder.encode( (a, b, (c, d)) ) ==
       AbiEncoder.encode(a) &
       AbiEncoder.encode(3 * 32'u8) & # offset of b in outer tuple
       AbiEncoder.encode(5 * 32'u8) & # offset of inner tuple in outer tuple
@@ -106,65 +90,29 @@ suite "ABI encoding":
       AbiEncoder.encode(2 * 32'u8) & # offset of d in inner tuple
       AbiEncoder.encode(d)
 
-  test "encodes element after dynamic tuple":
-    let a = @[1'u8, 2'u8, 3'u8]
-    let b = 0xAABBCCDD'u32
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.finishTuple()
-    encoder.write(b)
-    check encoder.finish() ==
-      AbiEncoder.encode(1 * 32'u8) & # offset of a in tuple
-      AbiEncoder.encode(a) &
-      AbiEncoder.encode(b)
-
   test "encodes arrays":
-    let element1 = seq[byte].example
-    let element2 = seq[byte].example
-    var expected= AbiEncoder.init()
-    expected.startTuple()
-    expected.write(element1)
-    expected.write(element2)
-    expected.finishTuple()
-    check AbiEncoder.encode([element1, element2]) == expected.finish()
+    let a, b = seq[byte].example
+    check AbiEncoder.encode([a, b]) == AbiEncoder.encode( (a,b) )
 
   test "encodes sequences":
-    let element1 = seq[byte].example
-    let element2 = seq[byte].example
-    var expected= AbiEncoder.init()
-    expected.write(2'u8)
-    expected.startTuple()
-    expected.write(element1)
-    expected.write(element2)
-    expected.finishTuple()
-    check AbiEncoder.encode(@[element1, element2]) == expected.finish()
+    let a, b = seq[byte].example
+    check AbiEncoder.encode(@[a, b]) ==
+      AbiEncoder.encode(2'u64) &
+      AbiEncoder.encode( (a, b) )
 
   test "encodes sequence as dynamic element":
     let s = @[42.u256, 43.u256]
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(s)
-    encoder.finishTuple()
-    check encoder.finish() ==
+    check AbiEncoder.encode( (s,) ) ==
       AbiEncoder.encode(32'u8) & # offset in tuple
       AbiEncoder.encode(s)
 
   test "encodes array of static elements as static element":
     let a = [[42'u8], [43'u8]]
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.finishTuple()
-    check encoder.finish() == AbiEncoder.encode(a)
+    check AbiEncoder.encode( (a,) ) == AbiEncoder.encode(a)
 
   test "encodes array of dynamic elements as dynamic element":
     let a = [@[42'u8], @[43'u8]]
-    var encoder= AbiEncoder.init()
-    encoder.startTuple()
-    encoder.write(a)
-    encoder.finishTuple()
-    check encoder.finish() ==
+    check AbiEncoder.encode( (a,) ) ==
       AbiEncoder.encode(32'u8) & # offset in tuple
       AbiEncoder.encode(a)