5.3. Tuple Pattern


	Chapter 5. Patterns
5.2. Variable Pattern	5.3. Tuple Pattern	5.4. List Pattern

Each element of a tuple pattern matches the corresponding element of a tuple value.

5.3.1. Syntax

[39] TuplePattern ::= ( Pattern , … , Pattern ) [ Tuple Size ≥ 2 ]

5.3.2. Type

When a tuple pattern ( P₀ , … , P_n ) is matched against a tuple type ( T₀ , … , T_n ), each P_i is matched against the corresponding T_i, producing typing contexts Γ_i. The typing context produced by the whole match is the union of the contexts Γ_i.

5.3.3. Examples

− Filtering

{- Publish a signal for each tuple with a first value of true -}

((false, true) | (true, false) | (false, false)) >(true, _)> signal

{-
OUTPUT:
signal
-}

− Pattern Publication

{- Publish 3, 6, and 9 in arbitrary order -}

(3,6,9)  >(x,y,z)>  ( x | y | z )

{-
OUTPUT:PERMUTABLE
3
6
9
-}

5.3.4. Related Links

Related Reference Topics

Tuples

Related Tutorial Sections

Patterns