Binary data [language.binary]

Use byte to denote binary data. Use seq[byte] for dynamic byte arrays.

Avoid string for binary data. If stdlib returns strings, convert to seq[byte] as early as possible


  • Explicit type for binary data helps convey intent


  • char and uint8 are common choices often seen in Nim
  • hidden assumption that 1 byte == 8 bits
  • language still being developed to handle this properly - many legacy functions return string for binary data

Practical notes

  • stew contains helpers for dealing with bytes and strings