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// RUN: %dafny /print:"%t.print" /env:0 /dprint:- "%s" > "%t"
// RUN: %diff "%s.expect" "%t"
datatype Color = Red | Green | Blue
// ----- match expressions in general positions
method M(c: Color, d: Color) {
var x := match c
case Red => 5
case Green => 7
case Blue => 11;
var y := match c
case Red => 0.3
case Green => (match d case Red => 0.18 case Green => 0.21 case Blue => 0.98)
case Blue => 98.0;
var z := match c
case Red => Green
case Green => match d {
case Red => Red
case Green => Blue
case Blue => Red
}
case Blue => Green;
var w := match c { case Red => 2 case Green => 3 case Blue => 4 } + 10;
var t := match c
case Red => 0
case Green => (match d {
case Red => 2
case Green => 2
case Blue => 1
} + (((match d case Red => 10 case Green => 8 case Blue => 5))))
case Blue => (match d {
case Red => 20
case Green => 20
case Blue => 10
} + (((match d case Red => 110 case Green => 108 case Blue => 105))));
}
// ----- match expressions in top-level positions
function Heat(c: Color): int
{
match c
case Red => 10
case Green => 12
case Blue => 14
}
function IceCream(c: Color): int
{
match c {
case Red => 0
case Green => 4
case Blue => 1
}
}
function Flowers(c: Color, d: Color): int
{
match c {
case Red =>
match d {
case Red => 0
case Green => 1
case Blue => 2
}
case Green =>
match d {
case Red => 3
case Green => 3
case Blue => 2
} + 20
case Blue =>
match d {
case Red => 9
case Green => 8
case Blue => 7
} +
((match d case Red => 23 case Green => 29 case Blue => 31))
}
}
// ----- match statements
method P(c: Color, d: Color) {
var x: int;
match c {
case Red =>
x := 20;
case Green =>
case Blue =>
}
match c
case Red =>
match d {
case Red =>
case Green =>
case Blue =>
}
case Green =>
var y := 25;
var z := y + 3;
case Blue =>
{
var y := 25;
var z := y + 3;
}
match d // note: this 'match' is part of the previous case
case Red =>
case Green =>
x := x + 1;
case Blue =>
}
lemma HeatIsEven(c: Color)
ensures Heat(c) % 2 == 0;
{
match c
case Red =>
assert 10 % 2 == 0;
case Green =>
assert 12 % 2 == 0;
case Blue => // all looks nice, huh? :)
// obvious
}
method DegenerateExamples(c: Color)
requires Heat(c) == 10; // this implies c == Red
{
match c
case Red =>
case Green =>
match c { }
case Blue =>
match c
}
method MoreDegenerateExamples(c: Color)
requires Heat(c) == 10; // this implies c == Red
{
if c == Green {
var x: int := match c;
var y: int := match c {};
var z := match c case Blue => 4;
}
}
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