§8 Pattern Matching

Literal patterns, _, guards, and enum-variant destructuring lower end-to-end. Compile-time exhaustiveness checking remains partial, so emitted matches retain a runtime backstop for an uncovered value.

match value {
    0               => print("zero"),
    n if n < 0      => print("negative"),
    Response.Ok { value } => process(value),
    Response.Error { code, message } => print.err("{{ code }}: {{ message }}"),
    _               => print("other"),
}

Pattern forms:

• Literal — 0, "hello", true
• Variable capture — any identifier binds the value
• Wildcard — _ matches anything, discards
• Enum destructuring — Variant { field } extracts payload fields
• Guard — pattern if condition adds a boolean filter
• Exhaustiveness — compile-time checking is partial; use a _ wildcard when the known variants do not cover every possible value