65 lines
1.4 KiB
Rust
65 lines
1.4 KiB
Rust
|
import option;
|
||
|
|
import option::some;
|
||
|
|
import option::none;
|
||
|
|
|
||
|
|
tag t[T, U] {
|
||
|
|
left(T);
|
||
|
|
right(U);
|
||
|
|
}
|
||
|
|
|
||
|
|
type operator[T, U] = fn(&T) -> U;
|
||
|
|
|
||
|
|
fn either[T, U, V](&operator[T, V] f_left,
|
||
|
|
&operator[U, V] f_right,
|
||
|
|
&t[T, U] value) -> V {
|
||
|
|
alt (value) {
|
||
|
|
case (left(?l)) { f_left(l) }
|
||
|
|
case (right(?r)) { f_right(r) }
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
fn lefts[T, U](&vec[t[T, U]] eithers) -> vec[T] {
|
||
|
|
let vec[T] result = [];
|
||
|
|
for (t[T, U] elt in eithers) {
|
||
|
|
alt (elt) {
|
||
|
|
case (left(?l)) { result += [l] }
|
||
|
|
case (_) { /* fallthrough */ }
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ret result;
|
||
|
|
}
|
||
|
|
|
||
|
|
fn rights[T, U](&vec[t[T, U]] eithers) -> vec[U] {
|
||
|
|
let vec[U] result = [];
|
||
|
|
for (t[T, U] elt in eithers) {
|
||
|
|
alt (elt) {
|
||
|
|
case (right(?r)) { result += [r] }
|
||
|
|
case (_) { /* fallthrough */ }
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ret result;
|
||
|
|
}
|
||
|
|
|
||
|
|
fn partition[T, U](&vec[t[T, U]] eithers) -> tup(vec[T], vec[U]) {
|
||
|
|
let vec[T] lefts = [];
|
||
|
|
let vec[U] rights = [];
|
||
|
|
for (t[T, U] elt in eithers) {
|
||
|
|
alt (elt) {
|
||
|
|
case (left(?l)) { lefts += [l] }
|
||
|
|
case (right(?r)) { rights += [r] }
|
||
|
|
}
|
||
|
|
}
|
||
|
|
ret tup(lefts, rights);
|
||
|
|
}
|
||
|
|
|
||
|
|
//
|
||
|
|
// Local Variables:
|
||
|
|
// mode: rust
|
||
|
|
// fill-column: 78;
|
||
|
|
// indent-tabs-mode: nil
|
||
|
|
// c-basic-offset: 4
|
||
|
|
// buffer-file-coding-system: utf-8-unix
|
||
|
|
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
|
||
|
|
// End:
|
||
|
|
//
|