gbury / ocaml-memgraph

A small library to output memory graph for ocaml values

Memgraph

A small library to output memory graph for ocaml values. Memgraph can be used to generate graphs that represent the memory layout of any valid ocaml value. Memgraph can produce .dot files that can then be processed using the graphviz suite of tools to generate images of the memory graph of ocaml values.

You can look at the examples folder to see how to use memgraph.

Memgraph & Kitty

For users of the kitty terminal emulator, you can use the Memgraph_kitty package and library to show the memory graph directly in a toplevel session (using ocaml or utop for instance).

WARNING: using this module in a terminal other than kitty may lead to weird behaviour, such as filling your screen with weird characters.

ocaml-memgraph's Issues

[feature wish] do not depend on unix in the core package

Using memgraph with js_of_ocaml currently raises a few warnings because of the dependency on unix (for Dot.to_file). It would be slightly cleaner to avoid depending on unix in the core library, and expose file-related helpers in a separate package.

closures and js_of_ocaml

Running ocaml-memgraph under js_of_ocaml means that the closure representation is different from native and bytecode.
For instance, trying to display the graph for (fun () () -> ()) will raise an assertion failure in mk_closinfo.

One idea would be to read Sys.backend_type to avoid reading into a closure block in the Other case.

difference with caml-inspect ?

Hello,

In case you were not aware of it, caml-inspect seems to do almost the same as ocaml-memgraph. And by the way, I use it in a document for an OCaml course.

Do you have precise needs or ideas to implement ?

Some of the colour arguments being passed to Graphviz are unquoted

Normally Graphviz accepts unquoted keywords (such as SVG or X11 colours) but hex values must be quoted. Calling memgraph after initialising the config with unquoted hex values triggers a syntax error. The following is how I properly configure the colours:

let config =
  Memgraph.Dot.config
    ~external_node_color:(Some "#bababa")
    ~block_node_color:(Some "#535955")
    ~root_node_color:(Some "#0a0a0a")
    ~outline_color:"\"#cccccc\""
    ~background_color:(Some "\"#252a2a\"")
    ~direction:`Horizontal
    ()

From a cursory look at the code, I suspect only the values parsed in styles_with_color get properly quoted and the others parsed in print_list don't.