Example
test utf16LeToUtf8 {
var utf16le: [2]u16 = undefined;
const utf16le_as_bytes = mem.sliceAsBytes(utf16le[0..]);
{
mem.writeInt(u16, utf16le_as_bytes[0..2], 'A', .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 'a', .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "Aa"));
}
{
mem.writeInt(u16, utf16le_as_bytes[0..2], 0x80, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xffff, .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "\xc2\x80" ++ "\xef\xbf\xbf"));
}
{
// the values just outside the surrogate half range
mem.writeInt(u16, utf16le_as_bytes[0..2], 0xd7ff, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xe000, .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "\xed\x9f\xbf" ++ "\xee\x80\x80"));
}
{
// smallest surrogate pair
mem.writeInt(u16, utf16le_as_bytes[0..2], 0xd800, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xdc00, .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "\xf0\x90\x80\x80"));
}
{
// largest surrogate pair
mem.writeInt(u16, utf16le_as_bytes[0..2], 0xdbff, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xdfff, .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "\xf4\x8f\xbf\xbf"));
}
{
mem.writeInt(u16, utf16le_as_bytes[0..2], 0xdbff, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xdc00, .little);
const utf8 = try utf16LeToUtf8Alloc(testing.allocator, &utf16le);
defer testing.allocator.free(utf8);
try testing.expect(mem.eql(u8, utf8, "\xf4\x8f\xb0\x80"));
}
{
mem.writeInt(u16, utf16le_as_bytes[0..2], 0xdcdc, .little);
mem.writeInt(u16, utf16le_as_bytes[2..4], 0xdcdc, .little);
const result = utf16LeToUtf8Alloc(testing.allocator, &utf16le);
try testing.expectError(error.UnexpectedSecondSurrogateHalf, result);
}
}