always use bytes offset as param

src/solidity/types/ArrayType.js

@@ -57,33 +57,25 @@ class ArrayType extends RefType {
   }
 
   decodeFromMemory (offset, memory) {
-    offset = 2 * offset
     var ret = []
-    var length = extractLength(this, offset, memory)
+    var length = this.arraySize
     if (this.arraySize === 'dynamic') {
-      offset = offset + 64
+      length = memory.substr(2 * offset, 64)
+      length = parseInt(length, 16)
+      offset = offset + 32
     }
     this.underlyingType.location = this.location
     for (var k = 0; k < length; k++) {
       var contentOffset = offset
       if (this.underlyingType.basicType === 'RefType') {
-        contentOffset = memory.substr(offset, 64)
+        contentOffset = memory.substr(2 * contentOffset, 64)
         contentOffset = parseInt(contentOffset, 16)
       }
       ret.push(this.underlyingType.decode(contentOffset, memory))
-      offset += 64
+      offset += 32
     }
     return ret
   }
 }
 
-function extractLength (type, offset, memory) {
-  var length = type.arraySize
-  if (length === 'dynamic') {
-    length = memory.substr(offset, 64)
-    length = parseInt(length, 16)
-  }
-  return length
-}
-
 module.exports = ArrayType

src/solidity/types/Struct.js

@@ -21,18 +21,17 @@ class Struct extends RefType {
   }
 
   decodeFromMemory (offset, memory) {
-    offset = 2 * offset
     var ret = {}
     this.members.map((item, i) => {
       var contentOffset = offset
       if (item.type.basicType === 'RefType') {
-        contentOffset = memory.substr(contentOffset, 64)
+        contentOffset = memory.substr(2 * contentOffset, 64)
         contentOffset = parseInt(contentOffset, 16)
       }
       item.type.location = this.location
       var member = item.type.decode(contentOffset, memory)
       ret[item.name] = member
-      offset += 64
+      offset += 32
     })
     return ret
   }

src/solidity/types/ValueType.js

@@ -28,7 +28,6 @@ class ValueType {
   }
 
   decode (offset, memory) {
-    offset = offset / 2
     return this.decodeFromMemory(offset, memory)
   }
 }