ugui/test/test_error.c3

72 lines
1016 B

import std::io;
struct FaultStack {
usz elem;
anyfault[16] v;
}
fn void FaultStack.push(&fs, anyfault f)
{
if (fs.elem < fs.v.len) {
fs.v[fs.elem++] = f;
}
}
fn anyfault FaultStack.pop(&fs)
{
return fs.elem > 0 ? fs.v[fs.elem-- - 1] : anyfault{};
}
FaultStack fs;
fn int! err1()
{
return IoError.OUT_OF_SPACE?;
}
fn void! err2()
{
return IoError.EOF?;
}
/*
macro @unwrap(#f)
{
$if ($typeof(#f).typeid == void!.typeid) {
if (catch err = #f) { fs.push(err); }
return;
} $else {
$typeof(#f) x = #f;
if (catch err = x) {
fs.push(err);
return $typeof(#f!!){};
} else {return x;}
}
}
*/
<*
@require @typekind(#func) == OPTIONAL : `@unwrap requires an optional value`
*>
macro @unwrap(#func)
{
anyfault exc = @catch(#func);
if (exc != anyfault{}) {
fs.push(exc);
$if $typeof(#func!!).typeid != void.typeid:
return $typeof(#func!!){};
$else
return;
$endif
} else {
return #func!!;
}
}
fn void main()
{
@unwrap(err1());
@unwrap(err2());
io::printfn("%s", fs.v);
}