Blorp by Example

Pattern Matching

match handles explicit cases and the compiler checks exhaustiveness.

Variants

Match union and enum variants by name.

match-variant.brp

match download:
    Running(n): print(n.to_string())
    _: print("not running")

Literals

Match literal strings, numbers, and booleans directly.

match-literal.brp

match command:
    "list": print("listing")
    _: print("unknown")

Tuples

Tuple patterns bind multiple positions at once.

tuple-match.brp

match (left, right):
    (Ok(a), Ok(b)): a + b
    _: 0

List Patterns

List patterns include [], [x], and [head, ...tail].

list-pattern.brp

match args:
    ["add", item]: item
    []: "missing"
    _: "unknown"

Wildcard

_ matches a value without binding it.

wildcard.brp

match result:
    Ok(value): value
    _: 0

Exhaustiveness

A match must cover every possible input shape.

exhaustive.brp

match status:
    Queued: "queued"
    Running(_): "running"
    Done(path): path
    Failed(msg): msg

Example

commands.brp

pure func route(args: List[String]) -> String:
	match args:
		["add", item]: "add " + item
		["list"]: "list"
		[cmd, ..._]: "unknown command: " + cmd
		[]: "missing command"


func main(args: List[String]) -> Void:
	print(route(["add", "milk"]))

Try It

terminal

blorp run commands.brp