48 lines
981 B
Rust
48 lines
981 B
Rust
/*
|
|
Module: util
|
|
*/
|
|
|
|
/*
|
|
Function: id
|
|
|
|
The identity function
|
|
*/
|
|
pure fn id<T: copy>(x: T) -> T { x }
|
|
|
|
/*
|
|
Function: unreachable
|
|
|
|
A standard function to use to indicate unreachable code. Because the
|
|
function is guaranteed to fail typestate will correctly identify
|
|
any code paths following the appearance of this function as unreachable.
|
|
*/
|
|
fn unreachable() -> ! {
|
|
fail "Internal error: entered unreachable code";
|
|
}
|
|
|
|
/* FIXME (issue #141): See test/run-pass/constrained-type.rs. Uncomment
|
|
* the constraint once fixed. */
|
|
/*
|
|
Function: rational
|
|
|
|
A rational number
|
|
*/
|
|
type rational = {num: int, den: int}; // : int::positive(*.den);
|
|
|
|
/*
|
|
Function: rational_leq
|
|
*/
|
|
pure fn rational_leq(x: rational, y: rational) -> bool {
|
|
// NB: Uses the fact that rationals have positive denominators WLOG:
|
|
|
|
x.num * y.den <= y.num * x.den
|
|
}
|
|
|
|
// Local Variables:
|
|
// mode: rust;
|
|
// fill-column: 78;
|
|
// indent-tabs-mode: nil
|
|
// c-basic-offset: 4
|
|
// buffer-file-coding-system: utf-8-unix
|
|
// End:
|