Grammar.parse() misses one letter, when parsing as bits

[alex9849]

When parsing a byte stream (bytes) using the grammar.parse()-method, the last letter is missing.

Steps to reproduce:

<start> ::= <entry_bit>
<entry_bit> ::= <bit>+
<entry_byte> ::= <byte>+
<byte> ::= <bit>{8}
<bit> ::= 0 | 1

Run:

with open("bit_grammar.fan") as f:
    grammar, constraints = parse(f, use_stdlib=False)
grammar.parse(b'test', NonTerminal("<entry_bit>")).to_bytes() # returns b'tes'
grammar.parse(b'test', NonTerminal("<entry_byte>")).to_bytes() # returns b'test'

[alex9849]

Also one case where parsing fails for me.
When pasing directly into bytes. Some bytes inputs also don't work.

grammar.parse(b'\x04test', NonTerminal("<entry_byte>")).to_bytes() # returns b'\x04test' <-- Works
grammar.parse(b'\x04test\x02', NonTerminal("<entry_byte>")).to_bytes() # returns b'\x04test\x02' <-- Works
grammar.parse(b'\x04test\x02d', NonTerminal("<entry_byte>")).to_bytes() # returns b'\x04test\x02' <-- Last letter missing
grammar.parse(b'\x04test\x02de', NonTerminal("<entry_byte>")).to_bytes() # returns b'\x04test\x02d' <-- Last letter missing

In this case the parser looses one letter when I add a second hexadecimal number to the parsing input.

[andreas-zeller]

Just to be sure: Is this in .parse() or in .to_bytes()? (Replace .to_bytes() by .value() and report the result)

[alex9849]

This is the result using the two example with .values() instead of .to_bytes()