Would be nice to iterate over a Vec<u8> or array and return a vector of TLV objects (at least for Simple-TLV case.

This repository is currently missing tags (and also releases) so it's a bit hard to follow the changes.

In tag.rs, impl TryFrom for Tag, fn try_from(v: u64):

//Line 273:
if len > 1 {
match bytes[3 - len] {
0x00 | 0x1E | 0x80 => return Err(TlvError::InvalidInput),
_ => (),
}
}

The 0x1E matches and rejects a valid TLV tag 9F1E which is the Interface Device Serial number on EMV cards: https://emvlab.org/emvtags/show/t9F1E/

Thanks,

Allan

Hi,
for my smart card driver I'm currently testing Your iso7816-tlv code, referring to pub mod simple;

My task is to parse something like this (hex values): [84, 1, 2C, 97, 0, 84, 1, 24, 9E, 1, 42], which is a sequence of simple-tlv.
There is a small, known set of valid 1-byte tags: 0x8?, 0x97, 0x9E and a few more; L is 1 byte as well, <255.
Depending on the tag value, different processing is involved: First is splitting by 0x8? tags, i.e.
in the simple case shown here, 2 simple-tlv form a "group of information", stored as a struct and pushed to a Vec, thus vector's len() will be 2 here.

The point (UpdateEdit) issue with Your code is: There is no public access to the Tlv struct members tag: Tag, value: Value, thus I introduced getter methods. Perhaps You may find that useful as well, or am I mistaken (I'm quite new to Rust):

$ diff -u3 ../iso7816-tlv-master/src/simple.rs iso7816-tlv/src/simple.rs
--- ../iso7816-tlv-master/src/simple.rs 2019-09-30 13:02:57.000000000 +0200
+++ iso7816-tlv/src/simple.rs   2019-10-30 13:22:09.343488554 +0100
@@ -87,6 +87,21 @@
     }
   }
 
+  /// Returns tag number of TLV
+  pub fn tag(&self) -> u8 {
+    self.tag.0
+  }
+
+  /// Returns length of TLV
+  pub fn length(&self) -> usize {
+    self.value.0.len()
+  }
+
+  /// Returns value of TLV
+  pub fn value(&self) -> &[u8] {
+    self.value.0.as_slice()
+  }
+
   /// serializes self into a byte vector.
   #[allow(clippy::cast_possible_truncation)]
   pub fn to_vec(&self) -> Vec<u8> {
$

There are no test for simple::Tlv parsing