OCaml: Add simulate (dry run) configuration option

ocaml/lib/parsers/config/lexer.ml

@@ -21,6 +21,8 @@ let lex_keyword (literal: string): token =
     match literal with
     | "su_command" -> Key SuCommand
     | "su_command_quoted" -> Key SuCommandQuoted
+    | "interactive" -> Key Interactive
+    | "simulate" -> Key Simulate
     | _ -> Key Unknown
 
 let lex_keyvalue (literal: string): token = Value literal
@@ -31,6 +33,7 @@ let string_of_token (token: token): string =
         | SuCommand -> "[ KEY: su_command ]"
         | SuCommandQuoted -> "[ KEY: su_command_quoted ]"
         | Interactive -> " [ KEY: interactive ]"
+        | Simulate -> " [ KEY: simulate ]"
         | Unknown -> "[ UNKNOWN KEY ]")
     | Equal -> "[ OP: equal ]"
     | Value v -> "[ VAL: " ^ v ^ " ]"

ocaml/lib/parsers/config/parser.ml

@@ -30,20 +30,14 @@ let check (config: Schema.main): Schema.main =
         { config with su_command_quoted = false }
     | Default, _ -> config
 
-let update config key (value: string): Schema.main =
+let update (config: Schema.main) (key: Lexer.key) (value: string): Schema.main =
     elog ~context:Parsing $ "[c.parser.update] Matching value '" ^ value ^ "'";
     match key with
-    | Schema.SuCommand ->
-        { config with Schema.su_command = String.split_on_char ' ' value }
-    | SuCommandQuoted ->
-        { config with
-            Schema.su_command_quoted = parse_boolean key value }
-    | Interactive ->
-        { config with
-            Schema.interactive = bool_of_string value }
-    | Unknown ->
-        elog ~context:Parsing $ "[c.parser.update] Dropped value: unknown key";
-        config
+    | SuCommand -> { config with su_command = String.split_on_char ' ' value }
+    | SuCommandQuoted -> { config with su_command_quoted = parse_boolean key value }
+    | Interactive -> { config with interactive = bool_of_string value }
+    | Simulate -> { config with simulate = bool_of_string value }
+    | Unknown -> elog ~context:Parsing $ "[c.parser.update] Dropped value: unknown key"; config
 
 let parse tokens: Schema.main =
     let rec parse_tokens tokens config ready_key =

ocaml/lib/schema/schema.ml

@@ -17,11 +17,17 @@ type os = Unknown | FreeBSD | Void | Alpine
 type host = { os : os; name : string }
 
 type default_bool = Default | true | false
-type configuration_key = SuCommand | SuCommandQuoted | Interactive | Unknown
+type configuration_key =
+    | SuCommand
+    | SuCommandQuoted
+    | Interactive
+    | Simulate
+    | Unknown
 type main = {
     su_command : string list;
     su_command_quoted: default_bool;
-    interactive: bool
+    interactive: bool;
+    simulate: bool;
 }
 type configuration = { main : main; }
 type input = { configuration: configuration; }
@@ -53,6 +59,7 @@ let origin : schema = {
                 su_command = [ "su"; "-c" ];
                 su_command_quoted = Default;
                 interactive = true;
+                simulate = false;
             };
         };
     };
@@ -78,6 +85,7 @@ let string_of_key key =
         | SuCommand -> "su_command"
         | SuCommandQuoted -> "su_command_quoted"
         | Interactive -> "interactive"
+        | Simulate -> "simulate"
         | Unknown -> "<unknown key>"
 
 let string_of_default_bool (b: default_bool): string =

ocaml/lib/system/package.ml

@@ -1,7 +1,7 @@
 open Utilities.Aliases
 
-type install = { interactive: string list; batch: string list }
-type manager = { install: install }
+type command = { interactive: string list; batch: string list }
+type manager = { install: command; remove: command }
 type manager_table = { apk: manager }
 
 let table: manager_table = {
@@ -9,6 +9,10 @@ let table: manager_table = {
         install = {
             interactive = [ "apk"; "-i"; "add"; ];
             batch = [ "apk"; "--no-interactive"; "add"; ];
+        };
+        remove = {
+            interactive = [ "apk"; "-i"; "del"; ];
+            batch = [ "apk"; "--no-interactive"; "del"; ];
         }
     }
 }
@@ -35,20 +39,28 @@ let merge (schema : Schema.schema) (packages : string list) : Schema.schema =
               };
               {
                 name = su_command;
-                arguments = su schema $ manager.install.interactive @ packages;
+                arguments = su schema $ manager.remove.interactive @ packages;
                 status = Unevaluated;
               };
             ]
         in
 
-        let ran = Process.Fork.run_many commands in
-        let formatted_ran = Process.Command.format_many ran in
+        let simulate = schema.input.configuration.main.simulate in
+        let log_output =
+            if simulate then
+                "Would execute:\n" ^
+                String.concat "\n" (Process.Command.format_many commands)
+            else
+                let ran =
+                    if simulate then [] else Process.Fork.run_many commands in
+                "Executed:\n" ^
+                String.concat "\n" (Process.Command.format_many ran) in
 
         {
           schema with
           output =
             {
               schema.output with
-              log = "Done:\n" ^ String.concat "\n" formatted_ran;
+              log = log_output;
             };
         }

ocaml/lib/system/process/command.ml

@@ -5,15 +5,15 @@ type schema = Schema.schema
 type status = Exit of int | Unevaluated
 type command = { name : string; arguments : string list; status : status }
 
-
 let format (command : command) : string =
     command.name ^ " with arguments: "
     ^ String.concat " " command.arguments
-    ^ " and result "
+    ^ " ("
     ^
-    match command.status with
-    | Exit n -> str_int n
-    | Unevaluated -> "Not evaluated"
+    (match command.status with
+        | Exit n -> "Exit status " ^ str_int n
+        | Unevaluated -> "Not evaluated")
+    ^ ")"
 
 let format_many (commands : command list) : string list =
     List.map format commands