internals/Template: fix bug in computing (deduplicated) deps

Template.deps used polymorphic compare, which led to failure when
comparing templates containing workflows which can be functional
values. Unbelievable it didn't occur earlier!

lib/engine/execution_env.ml

@@ -12,6 +12,8 @@ type insert =
     }
   | String of string
 
+let compare_insert = Poly.compare
+
 type t = {
   db : Db.t ;
   allowed_containers : [`Docker | `Singularity] list ;

lib/engine/execution_env.mli

@@ -9,6 +9,8 @@ type insert =
     }
   | String of string
 
+val compare_insert : insert -> insert -> int
+
 type t = {
   db : Db.t ;
   allowed_containers : [`Docker | `Singularity] list ;

lib/engine/shell_command.ml

@@ -91,7 +91,7 @@ let par x = "( " ^ x ^ " )"
    ))' which has a specific meaning for bash *)
 
 let command_path_deps cmd =
-  Command.deps cmd
+  Command.deps cmd ~compare:Execution_env.compare_insert
   |> List.filter_map ~f:(function
       | Execution_env.Path p -> Some [ p ]
       | Path_list l -> Some l.elts

lib/internals/command.ml

@@ -9,14 +9,15 @@ type 'a t =
 and 'a template = 'a Template.t
 
 
-let rec deps = function
+let rec deps cmd ~compare =
+  match cmd with
   | And_list xs
   | Or_list xs
   | Pipe_list xs ->
-    List.map xs ~f:deps
+    List.map xs ~f:(deps ~compare)
     |> List.concat
-    |> List.dedup_and_sort ~compare:Caml.compare
-  | Simple_command tokens -> Template.deps tokens
+    |> List.dedup_and_sort ~compare
+  | Simple_command tokens -> Template.deps tokens ~compare
 
 let rec map x ~f = match x with
   | Simple_command toks ->

lib/internals/command.mli

@@ -9,4 +9,4 @@ val map :
   f:('a -> 'b) ->
   'b t
 
-val deps : 'a t -> 'a list
+val deps : 'a t -> compare:('a -> 'a -> int) -> 'a list

lib/internals/template.ml

@@ -11,14 +11,14 @@ type 'a token =
 
 type 'a t = 'a token list
 
-let rec deps tmpl =
+let rec deps tmpl ~compare =
   List.map tmpl ~f:(function
       | D r -> [ r ]
-      | F toks -> deps toks
+      | F toks -> deps ~compare toks
       | S _ | DEST | TMP | NP | MEM -> []
     )
   |> List.concat
-  |> List.dedup_and_sort ~compare:Caml.compare
+  |> List.dedup_and_sort ~compare
 
 let rec map_token x ~f = match x with
   | S s -> S s

lib/internals/template.mli

@@ -14,4 +14,4 @@ val map :
   f:('a -> 'b) ->
   'b t
 
-val deps : 'a t -> 'a list
+val deps : 'a t -> compare:('a -> 'a -> int) -> 'a list

lib/internals/workflow.ml

@@ -143,6 +143,21 @@ let id : type s. s t -> string = function
 
 let any x = Any x
 
+let compare_token x y =
+  match x, y with
+  | Path_token wx, Path_token wy ->
+    String.compare (id wx) (id wy)
+  | Path_token _, _ -> -1
+  | Path_list_token x, Path_list_token y -> (
+      match String.compare (id x.elts) (id y.elts) with
+      | 0 -> compare (x.sep, x.quote) (y.sep, y.quote)
+      | i -> i
+    )
+  | Path_list_token _, _ -> -1
+  | String_token wx, String_token wy ->
+    String.compare (id wx) (id wy)
+  | String_token _, _ -> 1
+
 module Any = struct
   module T = struct
     type t = any
@@ -269,7 +284,7 @@ let shell
   in
   let id = digest ("shell", version, digestible_cmd cmd) in
   let deps = add_mem_dep mem (
-      Command.deps cmd
+      Command.deps cmd ~compare:compare_token
       |> List.map (function
           | Path_token w -> any w
           | Path_list_token { elts ; _ } -> any elts