add comments

src/solidity/types/RefType.js

@@ -10,6 +10,14 @@ class RefType {
     this.basicType = 'RefType'
   }
 
+  /**
+    * decode the type from the stack
+    *
+    * @param {Int} stackDepth - position of the type in the stack
+    * @param {Array} stack - stack
+    * @return {String} - memory
+    * @return {Object} - storage
+    */
   decodeFromStack (stackDepth, stack, memory, storage) {
     if (stack.length - 1 < stackDepth) {
       return { error: '<decoding failed - stack underflow ' + stackDepth + '>' }
@@ -19,6 +27,13 @@ class RefType {
     return decodeInternal(this, offset, memory, storage)
   }
 
+  /**
+    * decode the type with the @arg offset location from the memory or storage
+    *
+    * @param {Int} offset - position of the type in the memory
+    * @return {String} - memory
+    * @return {Object} - storage
+    */
   decode (offset, memory, storage) {
     offset = memory.substr(2 * offset, 64)
     offset = parseInt(offset, 16)

src/solidity/types/ValueType.js

@@ -9,11 +9,26 @@ class ValueType {
     this.basicType = 'ValueType'
   }
 
+  /**
+    * decode the type with the @arg location from the storage
+    *
+    * @param {Object} location - containing offset and slot
+    * @param {Object} storageContent - storageContent (storage)
+    * @return {Object} - decoded value
+    */
   decodeFromStorage (location, storageContent) {
     var value = util.extractHexValue(location, storageContent, this.storageBytes)
     return this.decodeValue(value)
   }
 
+  /**
+    * decode the type from the stack
+    *
+    * @param {Int} stackDepth - position of the type in the stack
+    * @param {Array} stack - stack
+    * @param {String} - memory
+    * @return {Object} - decoded value
+    */
   decodeFromStack (stackDepth, stack, memory) {
     if (stackDepth >= stack.length) {
       return this.decodeValue('')
@@ -22,11 +37,25 @@ class ValueType {
     }
   }
 
+  /**
+    * decode the type with the @arg offset location from the memory
+    *
+    * @param {Int} stackDepth - position of the type in the stack
+    * @return {String} - memory
+    * @return {Object} - decoded value
+    */
   decodeFromMemory (offset, memory) {
     var value = memory.substr(2 * offset, 64)
     return this.decodeValue(util.extractHexByteSlice(value, this.storageBytes, 0))
   }
 
+  /**
+    * decode the type with the @arg offset location from the memory
+    *
+    * @param {Int} offset - position of the type in the memory
+    * @return {String} - memory
+    * @return {Object} - storage
+    */
   decode (offset, memory) {
     return this.decodeFromMemory(offset, memory)
   }