igraph (c_lib): how to get incident edges - igraph

Question

I'm trying to implement code that retrieves the set of adjacent edges from my graph g. The igraph_es_incident and igraph_es_adj methods seem to be appropriate but the example they link to in the documentation doesn't seem to work.
The first issue is that the example code doesn't use the method in question (_incident) it instead uses the _adj method. The second issue is that the example method is different from the implementation and documentation.
Example code (4 inputs):
igraph_es_adj(&g, &it, i, IGRAPH_OUT);
Documentation and actual implementation (3 inputs):
int igraph_es_adj(igraph_es_t*, igraph_integer_t, igraph_neimode_t)
So, my question is how do I properly use the _incident or _adj method for my graph g?
Thank you
PS. Documentation on _incident: http://igraph.org/c/doc/igraph-docs.pdf page 211. Example code: https://github.com/igraph/igraph/blob/master/examples/simple/igraph_es_adj.c line 71.

Answer 1

I found the answer on page 208 of http://igraph.org/c/doc/igraph-docs.pdf. Here they show how to use the indexers for vids.

Answer 2

This code has worked to retrieve the neighbors of vid (j is the edge id you may look for):
igraph_integer_t vid = 0; // vertex vid in question
igraph_es_t es; // edge selector
igraph_eit_t it; // iterator
igraph_integer_t size; // to check the degree
igraph_es_incident(&es, vid, IGRAPH_ALL); // select edges from and to vid
igraph_es_size(&g, &es, &size); // how many edges?
printf("%d neighbors of %d \n",size,vid);
igraph_eit_create(&g, es, &it); // create iterator
IGRAPH_EIT_RESET(it); // and iterate
while(!IGRAPH_EIT_END(it)){
igraph_integer_t j = IGRAPH_EIT_GET(it);
IGRAPH_EIT_NEXT(it);
printf("%d is neighbor of %d \n",IGRAPH_OTHER(&g,j,vid),vid);
}