🧩 Rust Patterns §

• patterns consume values
• simple identifiers become local variables in the match arm

Types §

• Literal
  • matches an exact value / const
  • e.g. 100, "name"
• Range
  • matches any value in range
  • e.g. 0 ..= 10, 'a' .. 'e'
• Wildcard
  • matches anything: _
• Variable
  • Like wildcard, but moves/copies val into var
  • e.g. name
• Tuple
  • e.g. (key, value)
• Struct
  • e.g. StructName { field1: 12, field2}, StructName { field1: 12 ..}
• ref variable
  • Like Variable, but borrowing the val instead of moving/copying
  • e.g. ref name
• Subpattern
  • Matches pattern right of @, using var name to left
  • e.g. digit @ 0 ..=99, ref count @ .. 50
• Guards
  • Extra condition if CONDITION between pattern and arm
  • e.g. Some(name) if name == "John" => ...
• More on in chapter 10 of Programming Rust, 2nd edition

Where to use §

• match
• In place of an identifier (like JS destructuring)

Example §