- Fix Token::Keyword to use b"..." .to_vec() instead of static strings
- Improve unknown keyword diagnostics to show actual keyword bytes
- Remove unused has_valid_line_ending variable in stream keyword lexer
- Add stream_header_valid_line_endings test for stream keyword validation
All hex string lexer tests pass (16 unit tests + 2 proptests).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Bead-Id: pdftract-2hm4
Add two proptests for the PDF hex string lexer to verify robustness
and correctness:
1. proptest_hex_string_never_panics_on_random_bytes: Random byte
sequences starting with '<' (not '<<') never cause panics.
2. proptest_hex_string_roundtrip_via_reencode: Hex decode + re-encode
roundtrip property validates that encoding and decoding are
inverse operations.
The hex string lexer implementation was already present and correct,
with proper handling of odd-length zero padding (<4> -> \x40, not \x04).
All acceptance criteria pass:
- Empty hex string: <> -> b""
- Odd-length single nibble: <4> -> b"\x40" (critical test)
- Standard decoding: <48656C6C6F> -> b"Hello"
- Mixed case: <aBcD> -> b"\xAB\xCD"
- Whitespace ignored: <48 65> -> b"\x48\x65"
- Unterminated with diagnostic: <48 -> b"\x48" + STRUCT_UNTERMINATED_STRING
- Proptests pass: random bytes never panic, roundtrip property holds
- INV-8 maintained: all error paths use diagnostics, no panics
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Rename all DiagCode enum variants in the lexer to use the STRUCT_ prefix
to match the specification. This clarifies that these diagnostics relate
to structural/lexical issues in PDF documents.
Changes:
- InvalidName -> StructInvalidName
- InvalidHex -> StructInvalidHex
- InvalidOctal -> StructInvalidOctal
- InvalidStreamHeader -> StructInvalidStreamHeader
- UnexpectedEof -> StructUnexpectedEof
- UnterminatedString -> StructUnterminatedString
The hex string lexer implementation was already correct, with proper
handling of:
- Hex digit pair decoding
- Embedded whitespace (PDF spec 7.2.2)
- Odd-length zero padding: <4> -> \x40 (dangling nibble is HIGH)
- Invalid character diagnostics
- Unterminated string diagnostics
All 16 hex string tests pass, including critical tests for odd-length
padding and error handling.
See: notes/pdftract-2hm4.md
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
