make better cli

src/ligo/bin/cli.ml

@@ -1,3 +1,4 @@
+open Cmdliner
 open Trace
 
 let toplevel x =
@@ -6,44 +7,68 @@ let toplevel x =
   | Errors ss ->
       Format.printf "Errors: %a\n%!" errors_pp @@ List.map (fun f -> f()) ss
 
-let main () =
-  let l = Array.length Sys.argv in
-  let%bind () =
-    if l < 2
-    then simple_fail "Pass a command"
-    else ok () in
-  let command = Sys.argv.(1) in
-  match command with
-  | "compile" -> (
-      let sub_command = Sys.argv.(2) in
-      match sub_command with
-      | "file" -> (
-          let%bind () =
-            trace_strong (simple_error "bad number of args") @@
-            Assert.assert_equal_int 5 l in
-          let source = Sys.argv.(3) in
-          let entry_point = Sys.argv.(4) in
-          let%bind contract =
-            trace (simple_error "compile michelson") @@
-            Ligo.Contract.compile_contract_file source entry_point in
-          Format.printf "Contract:\n%s\n" contract ;
-          ok ()
-        )
-      | "expression" -> (
-          let%bind () =
-            trace_strong (simple_error "bad number of args") @@
-            Assert.assert_equal_int 6 l in
-          let source = Sys.argv.(3) in
-          let entry_point = Sys.argv.(4) in
-          let expression = Sys.argv.(5) in
-          let%bind value =
-            trace (simple_error "compile expression") @@
-            Ligo.Contract.compile_contract_parameter source entry_point expression in
-          Format.printf "Input:\n%s\n" value;
-          ok ()
-        )
-      | _ -> simple_fail "Bad sub-command"
-    )
-  | _ -> simple_fail "Bad command"
+let main =
+  let term = Term.(const print_endline $ const "Ligo needs a command. Do ligo --help") in
+  (term , Term.info "ligo")
 
-let () = toplevel @@ main ()
+let compile_file =
+  let f source entry_point =
+    toplevel @@
+    let%bind contract =
+      trace (simple_error "compile michelson") @@
+      Ligo.Contract.compile_contract_file source entry_point in
+    Format.printf "Contract:\n%s\n" contract ;
+    ok ()
+  in
+  let term =
+    let source =
+      let open Arg in
+      let info =
+        let docv = "SOURCE_FILE" in
+        let doc = "$(docv) is the path to the .ligo file of the contract." in
+        info ~docv ~doc [] in
+      required @@ pos 0 (some string) None info in
+    let entry_point =
+      let open Arg in
+      let info =
+        let docv = "ENTRY_POINT" in
+        let doc = "$(docv) is entry-point that will be compiled." in
+        info ~docv ~doc [] in
+      value @@ pos 1 string "main" info in
+    Term.(const f $ source $ entry_point) in
+  let docs = "Compile contracts." in
+  (term , Term.info ~docs "compile-contract")
+
+let compile_expression =
+  let f source entry_point expression =
+    toplevel @@
+    let%bind value =
+      trace (simple_error "compile-input") @@
+      Ligo.Contract.compile_contract_parameter source entry_point expression in
+    Format.printf "Input:\n%s\n" value;
+    ok ()
+  in
+  let term =
+    let source =
+      let open Arg in
+      let docv = "SOURCE_FILE" in
+      let doc = "$(docv) is the path to the .ligo file of the contract." in
+      let info = info ~docv ~doc [] in
+      required @@ pos 0 (some string) None info in
+    let entry_point =
+      let open Arg in
+      let docv = "ENTRY_POINT" in
+      let doc = "$(docv) is the entry-point of the contract." in
+      let info = info ~docv ~doc [] in
+      required @@ pos 1 (some string) None info in
+    let expression =
+      let open Arg in
+      let docv = "EXPRESSION" in
+      let doc = "$(docv) is the expression that will be compiled." in
+      let info = info ~docv ~doc [] in
+      required @@ pos 2 (some string) None info in
+    Term.(const f $ source $ entry_point $ expression) in
+  let docs = "Compile contracts parameters." in
+  (term , Term.info ~docs "compile-parameter")
+
+let () = Term.exit @@ Term.eval_choice main [compile_file ; compile_expression]

src/ligo/bin/dune

@@ -3,6 +3,7 @@
   (public_name ligo)
   (libraries
     tezos-utils
+    cmdliner
     ligo
   )
   (package ligo)