rust/src/comp/middle/ast_map.rs

import std::smallintmap;
import std::option;
import syntax::ast::*;
import syntax::visit;
import visit::vt;

tag ast_node {
    node_item(@item);
    node_obj_ctor(@item);
    node_native_item(@native_item);
    node_expr(@expr);
}

type map = std::map::hashmap[node_id, ast_node];

fn map_crate(c: &crate) -> map {
    // FIXME: This is using an adapter to convert the smallintmap
    // interface to the hashmap interface. It would be better to just
    // convert everything to use the smallintmap.
    let map = new_smallintmap_int_adapter[ast_node]();

    let v_map =
        @{visit_item: bind map_item(map, _, _, _),
          visit_native_item: bind map_native_item(map, _, _, _),
          visit_expr: bind map_expr(map, _, _, _)
             with *visit::default_visitor[()]()};
    visit::visit_crate(c, (), visit::mk_vt(v_map));
    ret map;
}

fn map_item(map: &map, i: &@item, e: &(), v: &vt[()]) {
    map.insert(i.id, node_item(i));
    alt i.node {
      item_obj(_, _, ctor_id) { map.insert(ctor_id, node_obj_ctor(i)); }
      _ { }
    }
    visit::visit_item(i, e, v);
}

fn map_native_item(map: &map, i: &@native_item, e: &(), v: &vt[()]) {
    map.insert(i.id, node_native_item(i));
    visit::visit_native_item(i, e, v);
}

fn map_expr(map: &map, ex: &@expr, e: &(), v: &vt[()]) {
    map.insert(ex.id, node_expr(ex));
    visit::visit_expr(ex, e, v);
}

fn new_smallintmap_int_adapter[@V]() -> std::map::hashmap[int, V] {
    let key_idx = fn (key: &int) -> uint { key as uint };
    let idx_key = fn (idx: &uint) -> int { idx as int };
    ret new_smallintmap_adapter(key_idx, idx_key);
}

// This creates an object with the hashmap interface backed
// by the smallintmap type, because I don't want to go through
// the entire codebase adapting all the callsites to the different
// interface.
// FIXME: hashmap and smallintmap should support the same interface.
fn new_smallintmap_adapter[@K,
                           @V](key_idx: fn(&K) -> uint ,
                               idx_key: fn(&uint) -> K ) ->
   std::map::hashmap[K, V] {

    obj adapter[@K,
                @V](map: smallintmap::smallintmap[V],
                    key_idx: fn(&K) -> uint ,
                    idx_key: fn(&uint) -> K ) {

        fn size() -> uint { fail }

        fn insert(key: &K, value: &V) -> bool {
            let exists = smallintmap::contains_key(map, key_idx(key));
            smallintmap::insert(map, key_idx(key), value);
            ret !exists;
        }

        fn contains_key(key: &K) -> bool {
            ret smallintmap::contains_key(map, key_idx(key));
        }

        fn get(key: &K) -> V { ret smallintmap::get(map, key_idx(key)); }

        fn find(key: &K) -> option::t[V] {
            ret smallintmap::find(map, key_idx(key));
        }

        fn remove(key: &K) -> option::t[V] { fail }

        fn rehash() { fail }

        iter items() -> @{key: K, val: V} {
            let idx = 0u;
            for item: option::t[V]  in map.v {
                alt item {
                  option::some(elt) {
                    let value = elt;
                    let key = idx_key(idx);
                    put @{key: key, val: value};
                  }
                  option::none. { }
                }
                idx += 1u;
            }
        }
        iter keys() -> K {
            for each p: @{key: K, val: V}  in self.items() { put p.key; }
        }
    }

    let map = smallintmap::mk[V]();
    ret adapter(map, key_idx, idx_key);
}

// 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: