/*-------------------------------------------------------------------------*\
* Metametho: __eq [boolean]
* Compare two edges.
* Example:
* e1 == e2 or e1 ~= e2 with metamethods
\*-------------------------------------------------------------------------*/
static int gr_equal(lua_State *L)
{
gr_edge_t *ud1 = toedge(L, 1, STRICT);
gr_edge_t *ud2 = toedge(L, 2, STRICT);
lua_pushboolean(L, (AGID(ud1->e) == AGID(ud2->e)));
return 1;
}
static int gr_tail(lua_State *L)
{
gr_edge_t *ud = toedge(L, 1, STRICT);
Agnode_t *n = ud->e->tail;
if (n == NULL){
lua_pushnil(L);
return 1;
} else
return get_object(L, n);
}
/*-------------------------------------------------------------------------*\
* Determines the graph to which of a node belongs.
* Returns graph userdata.
* Example:
* rv = n.graph
* Methods: n, err = e.head(self) and n, err = e.tail(self)
\*-------------------------------------------------------------------------*/
static int gr_graphof(lua_State *L)
{
gr_edge_t *ud = toedge(L, 1, STRICT);
gr_node_t *udh;
Agnode_t *head, *tail;
Agraph_t *g;
int rv;
head = ud->e->head;
tail = ud->e->tail;
rv = get_object(L, head);
udh = tonode(L, -rv, STRICT);
g = udh->subg;
lua_pop(L, rv);
return get_object(L, g);
}
/*-------------------------------------------------------------------------*\
* Method: e = nextedge(self, prev)
* Retrieves next edge of a node.
* Returns the next edge of the given node. With nil as prev the first
* edge is returned.
* Example:
* first = n:nextedge(nil)
* second = n:nextedge(first)
* third = n:nextedge(second)
\*-------------------------------------------------------------------------*/
static int gr_nextedge(lua_State *L)
{
int rv;
char sbuf[32];
Agraph_t *g;
Agedge_t *e;
gr_edge_t *ud_e;
gr_node_t *ud_n = tonode(L, 1, STRICT);
g = agroot(ud_n->n);
if (lua_isnil(L, 2)){
e = agfstedge(g, ud_n->n);
} else {
ud_e = toedge(L, 2, STRICT);
e = agnxtedge(g, ud_e->e, ud_n->n);
}
if (!e){
/* no more edges */
lua_pushnil(L);
return 1;
} else {
/* Check whether userdata exists .. */
rv = get_object(L, e);
if (rv == 1){
/* .. yes: return it */
return rv;
} else {
/* .. no: create it */
lua_pop(L, rv);
ud_e = lua_newuserdata(L, sizeof(gr_edge_t));
ud_e->e = e;
sprintf(sbuf, "edge@%lu", (unsigned long) AGID(e));
ud_e->name = strdup(sbuf);
ud_e->type = AGEDGE;
ud_e->status = ALIVE;
set_object(L, e);
return new_edge(L);
}
}
}
/*-------------------------------------------------------------------------*\
* Method: e.delete(self)
* Delete an edge.
* Returns non-nil on success.
* Example:
* rv, err = n:delete()
\*-------------------------------------------------------------------------*/
static int gr_delete(lua_State *L)
{
int rv = -1;
gr_edge_t *ud = toedge(L, 1, NONSTRICT);
Agraph_t *g;
if (ud->e != NULL){
g = ud->e->tail->graph;
TRACE("e.delete(): edge: ud=%p '%s' id=0x%x e=%p\n",
(void *) ud, ud->name, AGID(ud->e), (void *)ud->e);
del_object(L, ud->e);
agdelete(g, ud->e);
ud->e = NULL;
if (ud->name){
free(ud->name);
ud->name = NULL;
}
} else {
TRACE("e:delete(): ud=%p already closed\n", (void *)ud);
}
lua_pushnumber(L, rv);
return 1;
}
static int gr_nextinout(lua_State *L, edge_first_iter_t *fst, edge_next_iter_t *nxt)
{
int rv;
Agedge_t *e;
char sbuf[32];
gr_edge_t *ud_e;
gr_node_t *ud_n = tonode(L, 1, STRICT);
Agraph_t *g = agroot(ud_n->n);
if (lua_isnil(L, 2))
e = fst(g, ud_n->n);
else {
ud_e = toedge(L, 2, STRICT);
e = nxt(g, ud_e->e);
}
if (!e){
/* no more nodes */
lua_pushnil(L);
return 1;
} else {
/* Check whether userdata exists .. */
rv = get_object(L, e);
if (rv == 1)
/* .. yes: return it */
return rv;
else {
/* .. no: create it */
lua_pop(L, rv);
ud_e = lua_newuserdata(L, sizeof(gr_edge_t));
ud_e->e = e;
sprintf(sbuf, "edge@%lu", (unsigned long) AGID(e));
ud_e->name = strdup(sbuf);
ud_e->type = AGEDGE;
set_object(L, e);
return new_edge(L);
}
}
}
/*-------------------------------------------------------------------------*\
* Property: id [number]
* Get an edge's id.
* Example:
* n = e.id
\*-------------------------------------------------------------------------*/
static int gr_id(lua_State *L)
{
gr_edge_t *ud = toedge(L, 1, STRICT);
lua_pushnumber(L, AGID(ud->e));
return 1;
}
/*-------------------------------------------------------------------------*\
* Property: name [string]
* Provides the name of an edge.
* Example:
* name = e.name
\*-------------------------------------------------------------------------*/
static int gr_nameof(lua_State *L)
{
gr_edge_t *ud = toedge(L, 1, STRICT);
lua_pushstring(L, ud->name);
return 1;
}
