Module string 

Six-bit ASCII conversions and a fixed-capacity string type for decoded text fields (vessel name, callsign, destination).

Two distinct six-bit alphabets are involved:

• the NMEA armor alphabet, used to pack six-bit payload symbols into printable ASCII for the !AIVDM/!AIVDO payload field (armor_char_to_sixbit/sixbit_to_armor_char);
• the ITU-R M.1371 Annex 8 six-bit ASCII text alphabet, used inside the payload for string fields (sixbit_to_ascii/ascii_to_sixbit).

Structs

FixedStr

A fixed-capacity, stack-allocated string used for decoded text fields.

Functions

armor_char_to_sixbit

Converts one NMEA armor character back to its six-bit payload value.

ascii_to_sixbit

Converts an ASCII byte to its ITU-R M.1371 six-bit ASCII text value.

is_valid_armor_byte

Returns whether c is a valid NMEA armor character.

sixbit_to_armor_char

Converts a six-bit payload value (0..=63) to its NMEA armor character.

sixbit_to_ascii

Converts an ITU-R M.1371 six-bit ASCII text value (0..=63) to its ASCII byte.