Module vt_parser 

VT100 SGR parser for task output streams.

Converts raw byte chunks into StyledLine values — structured, styled representations of individual terminal output lines.

Parsing scope (MVP)

Handles what is needed for build-tool output:

• \n — emit current line
• \r — move cursor to column 0 (overwrite mode; does not clear the line — correct POSIX terminal behaviour, which also handles CRLF correctly)
• SGR sequences (\x1b[...m):
  • reset (0)
  • bold (1), italic (3), underline (4)
  • standard foreground (30–37), bright foreground (90–97), default fg (39)
  • standard background (40–47), bright background (100–107), default bg (49)
  • 256-colour fg/bg (38;5;n / 48;5;n)
  • truecolour fg/bg (38;2;r;g;b / 48;2;r;g;b)
• Unknown / malformed sequences — silently skipped, never panics
• Invalid UTF-8 — lossy replacement

Structs

Style

Text rendering style at a given position.

StyleSpan

A styled region within a StyledLine.

StyledLine

A single completed terminal output line with optional styling.

TerminalParser

Stateful, incremental VT100 SGR parser.

Enums

Color

A terminal colour value.