osmxml helper

gistfile1.rs

fn parse_relation(&mut self, attrs: sax::Attributes) -> ParseResult {
    let id = try!(self.parse_int_attr("id", attrs));
    let mut tags = HashMap::new();
    let mut members = Vec::new();

    try!(helper(self, "relation", |name, attrs, osm| {
        match name.as_slice() {
            "member" => members.push(try!(osm.parse_member(attrs))),
             "tag" => try!(osm.parse_tag(attrs, &mut tags)),
              _ => return Err(ParseErr(format!("Relations can only have members and tags. Got {}",name)))
        }
        Ok(())
    }));

    self.elements.insert(id, Relation{id: id, members: members, tags: tags});
    Ok(())
}

fn helper(osm: &mut Osm, tag: &'static str, c: |String, sax::Attributes, &mut Osm| -> ParseResult) -> ParseResult {
    for event in osm.parser.iter() {
        match event {
            Ok(sax::StartElement(name, attrs)) => try!(c(name, attrs, osm)),
            Ok(sax::EndElement(name)) => {
                if name.as_slice() == tag.as_slice() {
                    break;
                }
                return Err(ParseErr(format!(
                    "Expecting tag to end. Instead got a {}", name)));
            }
            _ => ()
        }
    }
    Ok(())
}