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// RUN: %dafny /compile:0 /print:"%t.print" /dprint:"%t.dprint" "%s" > "%t"
// RUN: %diff "%s.expect" "%t"
// ---------------------- chaining operators -----------------------------------
method TestChaining0(j: int, k: int, m: int)
requires j != k != m; // error: cannot have more than one != per chain
requires j == k == m; // dandy
requires j < k == m == m+1 != m+2 >= 100; // error: cannot mix < and >=
requires j >= k == m == m-1 != m-2 < 100; // error: cannot mix >= and <
{
}
method TestChaining1<T>(s: set<T>, t: set<T>, u: set<T>, x: T, SuperSet: set<set<T>>)
requires s <= t <= u >= s+u; // error: cannot mix <= and >=
ensures s <= u;
ensures s !! t !! u; // valid, means pairwise disjoint
ensures x in s in SuperSet; // error: 'in' is not chaining
ensures x !in s in SuperSet; // error: 'in' is not chaining
ensures x in s !in SuperSet; // error: 'in' is not chaining
ensures x in s == t; // error: 'in' is not chaining
{
}
method TestChaining2(a: set<int>, b: set<int>, c: set<int>)
{
var x := a !! b !! c;
var y := a !! b == c; // error
var z0 := a == (b !! c);
var z1 := (a == b) !! c;
var z2 := a == b !! c; // error: == and !! do not chain together (regression test)
}
// ---------------------- calc statements -----------------------------------
method TestCalc()
{
calc {} // OK, empty calculations are allowed
calc {
2 + 3; // OK, single-line calculations are allowed
}
calc {
2 + 3;
calc { // OK: a calc statement is allowed as a sub-hint
2;
1 + 1;
}
calc {
3;
1 + 2;
}
{ assert true; } // OK: multiple subhints are allowed between two lines
1 + 1 + 1 + 2;
{ assert 1 + 1 + 1 == 3; }
{ assert true; }
3 + 2;
}
calc != { // error: != is not allowed as the main operator of a calculation
2 + 3;
4;
}
calc { // OK, these operators are compatible
2 + 3;
> 4;
>= 2 + 2;
}
calc < { // OK, these operators are compatible
2 + 3;
== 5;
<= 3 + 3;
}
calc < { // error: cannot mix < and >= or >
2 + 3;
>= 5;
> 2 + 2;
6;
}
calc >= { // error: cannot mix >= and <= or !=
2 + 3;
<= 5;
!= 2 + 2;
3;
}
calc { // error: cannot have more than one != per calc
2 + 3;
!= 4;
!= 1 + 2;
3;
}
}
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