Represent combinators as diamond nodes in Mermaid diagram

Multi-input combinators (join, union, fixpoint) are now shown as
separate diamond-shaped nodes in the diagram:

    left --> combinator{join}
    right --> combinator
    combinator --> result

This makes the diagram more faithful to the actual data flow.

Author: cristianoc

analysis/reactive/src/Reactive.ml

@@ -97,6 +97,9 @@ module Registry = struct
 
   let nodes : (string, node_info) Hashtbl.t = Hashtbl.create 64
   let edges : (string * string, string) Hashtbl.t = Hashtbl.create 128
+  (* Combinator nodes: (combinator_id, (shape, inputs, output)) *)
+  let combinators : (string, string * string list * string) Hashtbl.t =
+    Hashtbl.create 32
   let dirty_nodes : string list ref = ref []
 
   let register ~name ~level ~process ~stats =
@@ -123,6 +126,10 @@ module Registry = struct
     | Some info -> info.upstream <- from_name :: info.upstream
     | None -> ()
 
+  (** Register a multi-input combinator (rendered as diamond in Mermaid) *)
+  let add_combinator ~name ~shape ~inputs ~output =
+    Hashtbl.replace combinators name (shape, inputs, output)
+
   let mark_dirty name =
     match Hashtbl.find_opt nodes name with
     | Some info when not info.dirty ->
@@ -133,33 +140,62 @@ module Registry = struct
   let clear () =
     Hashtbl.clear nodes;
     Hashtbl.clear edges;
+    Hashtbl.clear combinators;
     dirty_nodes := []
 
   (** Generate Mermaid diagram of the pipeline *)
   let to_mermaid () =
     let buf = Buffer.create 256 in
     Buffer.add_string buf "graph TD\n";
+    (* Collect edges that are part of combinators *)
+    let combinator_edges = Hashtbl.create 64 in
+    Hashtbl.iter
+      (fun comb_name (_, inputs, output) ->
+        List.iter
+          (fun input -> Hashtbl.replace combinator_edges (input, output) comb_name)
+          inputs)
+      combinators;
+    (* Output regular nodes *)
     Hashtbl.iter
       (fun name info ->
-        (* Node with level annotation *)
         Buffer.add_string buf
-          (Printf.sprintf "    %s[%s L%d]\n" name name info.level);
-        (* Edges with labels *)
+          (Printf.sprintf "    %s[%s L%d]\n" name name info.level))
+      nodes;
+    (* Output combinator nodes (diamond shape) *)
+    Hashtbl.iter
+      (fun comb_name (shape, _inputs, _output) ->
+        Buffer.add_string buf (Printf.sprintf "    %s{%s}\n" comb_name shape))
+      combinators;
+    (* Output edges *)
+    Hashtbl.iter
+      (fun name info ->
         List.iter
           (fun downstream ->
-            let label =
-              match Hashtbl.find_opt edges (name, downstream) with
-              | Some l -> l
-              | None -> ""
-            in
-            if label = "" then
-              Buffer.add_string buf
-                (Printf.sprintf "    %s --> %s\n" name downstream)
-            else
+            (* Check if this edge is part of a combinator *)
+            match Hashtbl.find_opt combinator_edges (name, downstream) with
+            | Some comb_name ->
+              (* Edge goes to combinator node instead *)
               Buffer.add_string buf
-                (Printf.sprintf "    %s -->|%s| %s\n" name label downstream))
+                (Printf.sprintf "    %s --> %s\n" name comb_name)
+            | None ->
+              let label =
+                match Hashtbl.find_opt edges (name, downstream) with
+                | Some l -> l
+                | None -> ""
+              in
+              if label = "" then
+                Buffer.add_string buf
+                  (Printf.sprintf "    %s --> %s\n" name downstream)
+              else
+                Buffer.add_string buf
+                  (Printf.sprintf "    %s -->|%s| %s\n" name label downstream))
           info.downstream)
       nodes;
+    (* Output edges from combinators to their outputs *)
+    Hashtbl.iter
+      (fun comb_name (_shape, _inputs, output) ->
+        Buffer.add_string buf (Printf.sprintf "    %s --> %s\n" comb_name output))
+      combinators;
     Buffer.contents buf
 
   (** Print timing stats for all nodes *)
@@ -711,6 +747,8 @@ let join ~name (left : ('k1, 'v1) t) (right : ('k2, 'v2) t) ~key_of ~f ?merge ()
   in
   Registry.add_edge ~from_name:left.name ~to_name:name ~label:"join";
   Registry.add_edge ~from_name:right.name ~to_name:name ~label:"join";
+  Registry.add_combinator ~name:(name ^ "_join") ~shape:"join"
+    ~inputs:[left.name; right.name] ~output:name;
 
   (* Subscribe to sources: just accumulate *)
   left.subscribe (fun delta ->
@@ -844,6 +882,8 @@ let union ~name (left : ('k, 'v) t) (right : ('k, 'v) t) ?merge () : ('k, 'v) t
   in
   Registry.add_edge ~from_name:left.name ~to_name:name ~label:"union";
   Registry.add_edge ~from_name:right.name ~to_name:name ~label:"union";
+  Registry.add_combinator ~name:(name ^ "_union") ~shape:"union"
+    ~inputs:[left.name; right.name] ~output:name;
 
   (* Subscribe to sources: just accumulate *)
   left.subscribe (fun delta ->
@@ -1046,6 +1086,8 @@ let fixpoint ~name ~(init : ('k, unit) t) ~(edges : ('k, 'k list) t) () :
   in
   Registry.add_edge ~from_name:init.name ~to_name:name ~label:"roots";
   Registry.add_edge ~from_name:edges.name ~to_name:name ~label:"edges";
+  Registry.add_combinator ~name:(name ^ "_fp") ~shape:"fixpoint"
+    ~inputs:[init.name; edges.name] ~output:name;
 
   (* Subscribe to sources: just accumulate *)
   init.subscribe (fun delta ->

analysis/reanalyze/diagrams/reactive-pipeline-full.mmd

@@ -1,127 +1,179 @@
 graph TD
     annotations[annotations L2]
-    annotations -->|join| solver.incorrect_dead_decls
-    annotations -->|join| liveness.annotated_roots
     exc_refs.exception_decls[exc_refs.exception_decls L3]
-    exc_refs.exception_decls -->|join| exc_refs.resolved_refs
     type_deps.same_path_refs[type_deps.same_path_refs L4]
-    type_deps.same_path_refs -->|union| type_deps.u1
     file_collection[file_collection L0]
-    file_collection -->|flatMap| file_data_collection
     decl_refs.value_decl_refs[decl_refs.value_decl_refs L7]
-    decl_refs.value_decl_refs -->|join| decl_refs.with_value_refs
     type_deps.combined_refs_to[type_deps.combined_refs_to L7]
-    type_deps.combined_refs_to -->|flatMap| type_deps.all_type_refs_from
     type_deps.all_type_refs_from[type_deps.all_type_refs_from L8]
-    type_deps.all_type_refs_from -->|union| liveness.type_refs_from
     type_deps.impl_needing_path2[type_deps.impl_needing_path2 L4]
-    type_deps.impl_needing_path2 -->|join| type_deps.impl_to_intf_refs_path2
     exc_refs.resolved_refs_from[exc_refs.resolved_refs_from L5]
-    exc_refs.resolved_refs_from -->|union| liveness.value_refs_from
     exc_refs.resolved_refs[exc_refs.resolved_refs L4]
-    exc_refs.resolved_refs -->|flatMap| exc_refs.resolved_refs_from
     type_deps.impl_to_intf_refs_path2[type_deps.impl_to_intf_refs_path2 L5]
-    type_deps.impl_to_intf_refs_path2 -->|union| type_deps.u2
     file_deps_map[file_deps_map L2]
     decl_refs.with_value_refs[decl_refs.with_value_refs L8]
-    decl_refs.with_value_refs -->|join| decl_refs.combined
     type_deps.u1[type_deps.u1 L5]
-    type_deps.u1 -->|union| type_deps.u2
     cross_file_items[cross_file_items L2]
-    cross_file_items -->|flatMap| exception_refs_collection
     decl_refs.decls_by_file[decl_refs.decls_by_file L3]
-    decl_refs.decls_by_file -->|join| decl_refs.type_decl_refs
-    decl_refs.decls_by_file -->|join| decl_refs.value_decl_refs
     type_deps.impl_to_intf_refs[type_deps.impl_to_intf_refs L4]
-    type_deps.impl_to_intf_refs -->|union| type_deps.u1
     solver.issues_by_file[solver.issues_by_file L17]
-    solver.issues_by_file -->|flatMap| solver.modules_with_reported
     liveness.annotated_roots[liveness.annotated_roots L3]
-    liveness.annotated_roots -->|union| liveness.all_roots
     solver.incorrect_dead_decls[solver.incorrect_dead_decls L16]
     type_deps.intf_to_impl_refs[type_deps.intf_to_impl_refs L4]
-    type_deps.intf_to_impl_refs -->|union| type_deps.combined_refs_to
     type_deps.decl_by_path[type_deps.decl_by_path L3]
-    type_deps.decl_by_path -->|join| type_deps.intf_to_impl_refs
-    type_deps.decl_by_path -->|join| type_deps.impl_to_intf_refs_path2
-    type_deps.decl_by_path -->|join| type_deps.impl_needing_path2
-    type_deps.decl_by_path -->|join| type_deps.impl_to_intf_refs
-    type_deps.decl_by_path -->|flatMap| type_deps.same_path_refs
     type_deps.u2[type_deps.u2 L6]
-    type_deps.u2 -->|union| type_deps.combined_refs_to
     solver.live_decls[solver.live_decls L15]
-    solver.live_decls -->|join| solver.incorrect_dead_decls
-    solver.live_decls -->|flatMap| solver.modules_with_live
     type_deps.impl_decls[type_deps.impl_decls L3]
-    type_deps.impl_decls -->|join| type_deps.impl_needing_path2
-    type_deps.impl_decls -->|join| type_deps.impl_to_intf_refs
     liveness.all_roots[liveness.all_roots L12]
-    liveness.all_roots -->|roots| liveness.live
     solver.dead_modules[solver.dead_modules L17]
-    solver.dead_modules -->|join| solver.dead_module_issues
     liveness.external_type_refs[liveness.external_type_refs L10]
-    liveness.external_type_refs -->|union| liveness.externally_referenced
     decl_refs.combined[decl_refs.combined L12]
-    decl_refs.combined -->|flatMap| liveness.edges
     type_refs_from[type_refs_from L2]
-    type_refs_from -->|union| liveness.type_refs_from
     liveness.type_refs_from[liveness.type_refs_from L9]
-    liveness.type_refs_from -->|join| liveness.external_type_refs
-    liveness.type_refs_from -->|join| decl_refs.type_decl_refs
     solver.dead_decls_by_file[solver.dead_decls_by_file L16]
-    solver.dead_decls_by_file -->|flatMap| solver.issues_by_file
     liveness.external_value_refs[liveness.external_value_refs L7]
-    liveness.external_value_refs -->|union| liveness.externally_referenced
     liveness.value_refs_from[liveness.value_refs_from L6]
-    liveness.value_refs_from -->|join| liveness.external_value_refs
-    liveness.value_refs_from -->|join| decl_refs.value_decl_refs
     value_refs_from[value_refs_from L2]
-    value_refs_from -->|union| liveness.value_refs_from
     solver.modules_with_dead[solver.modules_with_dead L16]
-    solver.modules_with_dead -->|join| solver.dead_modules
     solver.dead_decls[solver.dead_decls L15]
-    solver.dead_decls -->|flatMap| solver.dead_decls_by_file
-    solver.dead_decls -->|flatMap| solver.modules_with_dead
     exception_refs_collection[exception_refs_collection L3]
-    exception_refs_collection -->|join| exc_refs.resolved_refs
     type_deps.intf_decls[type_deps.intf_decls L3]
-    type_deps.intf_decls -->|join| type_deps.intf_to_impl_refs
     file_data_collection[file_data_collection L1]
-    file_data_collection -->|flatMap| files
-    file_data_collection -->|flatMap| file_deps_map
-    file_data_collection -->|flatMap| cross_file_items
-    file_data_collection -->|flatMap| type_refs_from
-    file_data_collection -->|flatMap| value_refs_from
-    file_data_collection -->|flatMap| annotations
-    file_data_collection -->|flatMap| decls
     solver.dead_module_issues[solver.dead_module_issues L19]
     decl_refs.with_type_refs[decl_refs.with_type_refs L11]
-    decl_refs.with_type_refs -->|join| decl_refs.combined
     solver.modules_with_live[solver.modules_with_live L16]
-    solver.modules_with_live -->|join| solver.dead_modules
     decl_refs.type_decl_refs[decl_refs.type_decl_refs L10]
-    decl_refs.type_decl_refs -->|join| decl_refs.with_type_refs
     files[files L2]
     solver.modules_with_reported[solver.modules_with_reported L18]
-    solver.modules_with_reported -->|join| solver.dead_module_issues
     liveness.externally_referenced[liveness.externally_referenced L11]
-    liveness.externally_referenced -->|union| liveness.all_roots
     liveness.edges[liveness.edges L13]
-    liveness.edges -->|edges| liveness.live
     liveness.live[liveness.live L14]
-    liveness.live -->|join| solver.live_decls
-    liveness.live -->|join| solver.dead_decls
     decls[decls L2]
-    decls -->|join| solver.live_decls
-    decls -->|join| solver.dead_decls
-    decls -->|join| liveness.annotated_roots
-    decls -->|join| liveness.external_type_refs
-    decls -->|join| liveness.external_value_refs
-    decls -->|join| decl_refs.with_type_refs
-    decls -->|join| decl_refs.with_value_refs
+    type_deps.intf_to_impl_refs_join{join}
+    liveness.external_value_refs_join{join}
+    type_deps.impl_to_intf_refs_path2_join{join}
+    solver.incorrect_dead_decls_join{join}
+    liveness.value_refs_from_union{union}
+    exc_refs.resolved_refs_join{join}
+    type_deps.combined_refs_to_union{union}
+    liveness.externally_referenced_union{union}
+    solver.dead_modules_join{join}
+    liveness.all_roots_union{union}
+    solver.dead_module_issues_join{join}
+    solver.dead_decls_join{join}
+    liveness.annotated_roots_join{join}
+    decl_refs.value_decl_refs_join{join}
+    type_deps.impl_to_intf_refs_join{join}
+    solver.live_decls_join{join}
+    decl_refs.with_value_refs_join{join}
+    liveness.type_refs_from_union{union}
+    type_deps.impl_needing_path2_join{join}
+    liveness.external_type_refs_join{join}
+    liveness.live_fp{fixpoint}
+    decl_refs.type_decl_refs_join{join}
+    type_deps.u2_union{union}
+    decl_refs.combined_join{join}
+    type_deps.u1_union{union}
+    decl_refs.with_type_refs_join{join}
+    annotations --> solver.incorrect_dead_decls_join
+    annotations --> liveness.annotated_roots_join
+    exc_refs.exception_decls --> exc_refs.resolved_refs_join
+    type_deps.same_path_refs --> type_deps.u1_union
+    file_collection -->|flatMap| file_data_collection
+    decl_refs.value_decl_refs --> decl_refs.with_value_refs_join
+    type_deps.combined_refs_to -->|flatMap| type_deps.all_type_refs_from
+    type_deps.all_type_refs_from --> liveness.type_refs_from_union
+    type_deps.impl_needing_path2 --> type_deps.impl_to_intf_refs_path2_join
+    exc_refs.resolved_refs_from --> liveness.value_refs_from_union
+    exc_refs.resolved_refs -->|flatMap| exc_refs.resolved_refs_from
+    type_deps.impl_to_intf_refs_path2 --> type_deps.u2_union
+    decl_refs.with_value_refs --> decl_refs.combined_join
+    type_deps.u1 --> type_deps.u2_union
+    cross_file_items -->|flatMap| exception_refs_collection
+    decl_refs.decls_by_file --> decl_refs.type_decl_refs_join
+    decl_refs.decls_by_file --> decl_refs.value_decl_refs_join
+    type_deps.impl_to_intf_refs --> type_deps.u1_union
+    solver.issues_by_file -->|flatMap| solver.modules_with_reported
+    liveness.annotated_roots --> liveness.all_roots_union
+    type_deps.intf_to_impl_refs --> type_deps.combined_refs_to_union
+    type_deps.decl_by_path --> type_deps.intf_to_impl_refs_join
+    type_deps.decl_by_path --> type_deps.impl_to_intf_refs_path2_join
+    type_deps.decl_by_path --> type_deps.impl_needing_path2_join
+    type_deps.decl_by_path --> type_deps.impl_to_intf_refs_join
+    type_deps.decl_by_path -->|flatMap| type_deps.same_path_refs
+    type_deps.u2 --> type_deps.combined_refs_to_union
+    solver.live_decls --> solver.incorrect_dead_decls_join
+    solver.live_decls -->|flatMap| solver.modules_with_live
+    type_deps.impl_decls --> type_deps.impl_needing_path2_join
+    type_deps.impl_decls --> type_deps.impl_to_intf_refs_join
+    liveness.all_roots --> liveness.live_fp
+    solver.dead_modules --> solver.dead_module_issues_join
+    liveness.external_type_refs --> liveness.externally_referenced_union
+    decl_refs.combined -->|flatMap| liveness.edges
+    type_refs_from --> liveness.type_refs_from_union
+    liveness.type_refs_from --> liveness.external_type_refs_join
+    liveness.type_refs_from --> decl_refs.type_decl_refs_join
+    solver.dead_decls_by_file -->|flatMap| solver.issues_by_file
+    liveness.external_value_refs --> liveness.externally_referenced_union
+    liveness.value_refs_from --> liveness.external_value_refs_join
+    liveness.value_refs_from --> decl_refs.value_decl_refs_join
+    value_refs_from --> liveness.value_refs_from_union
+    solver.modules_with_dead --> solver.dead_modules_join
+    solver.dead_decls -->|flatMap| solver.dead_decls_by_file
+    solver.dead_decls -->|flatMap| solver.modules_with_dead
+    exception_refs_collection --> exc_refs.resolved_refs_join
+    type_deps.intf_decls --> type_deps.intf_to_impl_refs_join
+    file_data_collection -->|flatMap| files
+    file_data_collection -->|flatMap| file_deps_map
+    file_data_collection -->|flatMap| cross_file_items
+    file_data_collection -->|flatMap| type_refs_from
+    file_data_collection -->|flatMap| value_refs_from
+    file_data_collection -->|flatMap| annotations
+    file_data_collection -->|flatMap| decls
+    decl_refs.with_type_refs --> decl_refs.combined_join
+    solver.modules_with_live --> solver.dead_modules_join
+    decl_refs.type_decl_refs --> decl_refs.with_type_refs_join
+    solver.modules_with_reported --> solver.dead_module_issues_join
+    liveness.externally_referenced --> liveness.all_roots_union
+    liveness.edges --> liveness.live_fp
+    liveness.live --> solver.live_decls_join
+    liveness.live --> solver.dead_decls_join
+    decls --> solver.live_decls_join
+    decls --> solver.dead_decls_join
+    decls --> liveness.annotated_roots_join
+    decls --> liveness.external_type_refs_join
+    decls --> liveness.external_value_refs_join
+    decls --> decl_refs.with_type_refs_join
+    decls --> decl_refs.with_value_refs_join
     decls -->|flatMap| decl_refs.decls_by_file
     decls -->|flatMap| exc_refs.exception_decls
     decls -->|flatMap| type_deps.intf_decls
     decls -->|flatMap| type_deps.impl_decls
     decls -->|flatMap| type_deps.decl_by_path
+    type_deps.intf_to_impl_refs_join --> type_deps.intf_to_impl_refs
+    liveness.external_value_refs_join --> liveness.external_value_refs
+    type_deps.impl_to_intf_refs_path2_join --> type_deps.impl_to_intf_refs_path2
+    solver.incorrect_dead_decls_join --> solver.incorrect_dead_decls
+    liveness.value_refs_from_union --> liveness.value_refs_from
+    exc_refs.resolved_refs_join --> exc_refs.resolved_refs
+    type_deps.combined_refs_to_union --> type_deps.combined_refs_to
+    liveness.externally_referenced_union --> liveness.externally_referenced
+    solver.dead_modules_join --> solver.dead_modules
+    liveness.all_roots_union --> liveness.all_roots
+    solver.dead_module_issues_join --> solver.dead_module_issues
+    solver.dead_decls_join --> solver.dead_decls
+    liveness.annotated_roots_join --> liveness.annotated_roots
+    decl_refs.value_decl_refs_join --> decl_refs.value_decl_refs
+    type_deps.impl_to_intf_refs_join --> type_deps.impl_to_intf_refs
+    solver.live_decls_join --> solver.live_decls
+    decl_refs.with_value_refs_join --> decl_refs.with_value_refs
+    liveness.type_refs_from_union --> liveness.type_refs_from
+    type_deps.impl_needing_path2_join --> type_deps.impl_needing_path2
+    liveness.external_type_refs_join --> liveness.external_type_refs
+    liveness.live_fp --> liveness.live
+    decl_refs.type_decl_refs_join --> decl_refs.type_decl_refs
+    type_deps.u2_union --> type_deps.u2
+    decl_refs.combined_join --> decl_refs.combined
+    type_deps.u1_union --> type_deps.u1
+    decl_refs.with_type_refs_join --> decl_refs.with_type_refs