txref BIP needs pull request for txos

[dcdpr]

No description provided.

[dcdpr]

PR should include a reference classifyInputString().

[dcdpr]

Our current proposed text surrounding classifyInputString() is as follows:

Among input strings that are well formed bech32 strings, the
following two length checks may be used to discriminate between
txref and txrefext inputs:

const int TXREF_STRING_MIN_LENGTH = 17;              // ex: "tx1rqqqqqqqqmhuqk"
const int TXREF_EXT_STRING_MIN_LENGTH = 20;          // ex: "tx1rqqqqqqqqqquau7hl"
const int TXREF_STRING_MIN_LENGTH_TESTNET = 23;      // ex: "txtest1xqqqqqqqqqkn3gh9"
const int TXREF_EXT_STRING_MIN_LENGTH_TESTNET = 26;  // ex: "txtest1xqqqqqqqqqqqqj7dvzy"

enum InputParam { unknown_param, txref_param, txrefext_param };

// before testing for various txrefs, get rid of any unknown characters
std::string s = bech32::stripUnknownChars(str);

if(s.length() == TXREF_STRING_MIN_LENGTH ||
   s.length() == TXREF_STRING_MIN_LENGTH_TESTNET) {
    return txref_param;
}

if(s.length() == TXREF_EXT_STRING_MIN_LENGTH ||
   s.length() == TXREF_EXT_STRING_MIN_LENGTH_TESTNET) {
    return txrefext_param;
}

return unknown_param;

Example in context

[rxgrant]

see https://github.com/veleslavs/bips/blob/txrev_v2/bip-0136.mediawiki
and veleslavs/bips#4