Switch statements

The switch statement is similiar to that of Java. Unlike Java, the switch statement does not include fallthroughs.

switch (v) {
    case 0:
    case 1:
        trace("zero or one");
    default:
        trace("other");
}

The switch type statement is used to match the type of a discriminant value.

switch type (v) {
    case (d : Date) {
    }
    default {
    }
}

The switch type statement also supports pattern matching on algebraic data types.

switch type (exp) {
    case (Plus(10, right)) {
    }
}

Syntax

SwitchStatement :
switch ParenListExpression { CaseElements^abbrev }
switch [no line break] type ParenListExpression { TypeCaseElements }

CaseElements^ω :
«empty»
CaseElement^ω
CaseElements^full CaseElement^ω

CaseElement^ω :
CaseLabel_{1,} CaseDirectives^ω

CaseLabel :
case ListExpression^allowIn :
default :

CaseDirectives^ω :
Directive^ω
CaseDirectives^full Directive^ω

TypeCaseElements :
«empty»
TypeCaseElement
TypeCaseElements TypeCaseElement

TypeCaseElement :
case ( TypedPattern ) Block
default Block