Update TLV8.md

docs/TLV8.md

@@ -22,13 +22,13 @@ Fortunately, HomeSpan includes a dedicated TLV8 library (see below) that automat
 
 ## *TLV8()*
 
-Creating an instance of HomeSpan's TLV8 **class** using the above constructor builds an empty TLV8 object into which you can add and process TLV8 records.  TLV8 objects are instantiated as standard C++ linked-list containers derived from `std::list<tlv8_t>`, where *tlv8_t* is an opaque structure used to store individual TLV8 records.[^1]
+Creating an instance of HomeSpan's TLV8 **class** using the above constructor builds an empty TLV8 object into which you can add and process TLV8 records.  TLV8 objects are instantiated as standard C++ linked-list containers derived from `std::list<tlv8_t>`, where *tlv8_t* is an opaque structure used to store individual TLV8 records.[^opaque]
 
-Also, as shown below, many of the TLV8 methods utilize linked-list iterators.  These are represented by the typedef *TLV8_it*.[^2] 
+Also, as shown below, many of the TLV8 methods utilize linked-list iterators.  These are represented by the typedef *TLV8_it*.[^iterators] 
 
-[^1]:The *tlv8_t* structure is opaque because in general you will not have to create or interact directly with the structure or its data.  Note that in addition to the above TLV8-specific methods, you can use any `std::list` method with a TLV8 object if desired.
+[^opaque]:The *tlv8_t* structure is opaque because in general you will not have to create or interact directly with the structure or its data.  Note that in addition to the above TLV8-specific methods, you can use any `std::list` method with a TLV8 object if desired.
 
-[^2]:You do not need expert knowledge of C++ containers and iterators in order to use the TLV8 library, but a basic understanding of containers and iterators will make the library much easier to learn and enjoyable to use.
+[^iterators]:You do not need expert knowledge of C++ containers and iterators in order to use the TLV8 library, but a basic understanding of containers and iterators will make the library much easier to learn and enjoyable to use.
 
 The method for adding a generic TLV8 record to a TLV8 object is as follows:
 
@@ -115,6 +115,18 @@ To restrict the the printing range to a limited set of records, add optional sta
   * if *it2* is unspecified, prints only the record pointed to by *it1*
   * note `myTLV.print()` is equivalent to `myTLV.print(myTLV.begin(), myTLV.end())`
 
+The output generated by `print()` can contain some very long lines, especially if the VALUE of some of the TLV8 records represents other complete TLV8 objects (known as sub-TLVs or "nested" TLVs).  To recursively print all sub-TLV objects, use the following method:
+
+* `void printAll()`
+  * recursively prints all TLV8 records, one per line, to the Serial Monitor
+  * inspects each TLV8 record and tries to parse as if the record represented a sub-TLV object
+    * if parsing is successful, prints the record and then calls `printAll()` on the sub-TLV
+    * if not, prints the record and ends this branch of the recursion
+  * the format of each line is the same as that of `print()` except that TAG displays the full path of all TAGs through the branch
+  * note that the output can be very voluminous if your TLV8 object contains many levels of nested sub-TLVs
+  * warning: some care is required when interpretating the output[^subTLVs]
+  
+[^subTLVs]:The `printAll()` method assumes that any VALUE that is consistent with the format of a sub-TLV must be a sub-TLV, even if its just a simple numeric value.  For example, `add(10,65536)` yields a record with a TAG identifer of 10 and a 4-byte VALUE of 0x00000100.  The `printAll()` method will display this record along with NUMERIC=65536, but it will also then interpret (and thus display) this VALUE as a sub-TLV containing one zero-length record with TAG identifier=0 and another zero-length record with TAG identifer=1, since the VALUE can be successfully parsed as such.
 
 Once you have the iterator *myIT* pointing to the desired TLV8 record, you can then use any of the methods below to access the VALUE stored in the TLV8 record: