erlang

Why would one use void *enif_alloc_resource(ErlNifResourceType* type, unsigned size) as opposed to void *enif_alloc(size_t size) when trying to allocate memory from an Erlang C NIF? Reference does not specify much as to why. http://www.erlang.org/doc/man/erl_nif.html#enif_alloc enif_alloc_resource is used to create resources which are garbage collected by the vm when not used any more. enif_alloc works just like malloc, only is uses an Erlang VM specific implementation rather than the OSs malloc. Take a look at the documentation for ErlNifResourceType and the functions which use it for some

There is a lot of example implementations of generating a powerset of a set in Java, Python and others, but I still can not understand how the actual algorithm works. What are the steps taken by an algorithm to generate a power set P(S) of a set S? (For example, the power set of {1,2,3,4} is {{}, {1}, {2}, {1,2}, {3}, {1,3}, {2,3}, {1,2,3}, {4}, {1,4}, {2,4}, {1,2,4}, {3,4}, {1,3,4}, {2,3,4}, {1,2,3,4}}.) UPD: I have found this explanation, but still I don't get it. I am trying to understand the algorithm of generating a power set, because I would like to write a parallel implementation of it

I have two lists of vertices: V and S . I would like to generate all possible directed graphs from V and S so, that each vertex from V has only one out-edge and exactly one in-edge, and each vertex from S can have any number of in- and out- edges. Each graph in the result should contain exactly all vertices from V and from S . The result can contain both connected and disconnected graphs. First I thought it was a powerset-related problem, but powerset has many other sets that may contain just one element (and I do not need those). My current strategy is to: find all pairs between vertices from

I was wondering what the most suitable tool is for extracting c (and eventually c++) function names, arguments and their types from source code. I would like to use a tool that can be automated as much as possible. I want to extract the signature types then have the output read by another program written in Erlang. My goal is to use this information to construct the equivalent of the C types/signatures in Erlang (using ei). I would like this process to work for any C file so I can't use any hardcoded stuff. I have found a lot of tools that look promising like CLang, CScope and ANTLR and so on