1 files changed, 29 insertions, 12 deletions

diff --git a/syntax/type_of.ml b/syntax/type_of.ml
index 5ef90f4..0a6bf34 100644
--- a/syntax/type_of.ml
+++ b/syntax/type_of.ml
@@ -7,6 +7,8 @@ module Helper = struct
   type t = Integer | Bool | String | Any
   [@@deriving show { with_path = false }]
 
+  type argument_repr = { pos : pos; t : t }
+
   type dyn_type = t -> t
   (** Dynamic type is a type unknown during the code.
 
@@ -32,10 +34,14 @@ module Helper = struct
   type argument = Fixed of t | Dynamic of dyn_type | Variable of argument
 
   let compare :
-      ?level:Report.level -> t -> pos * t -> Report.t list -> Report.t list =
+      ?level:Report.level ->
+      t ->
+      argument_repr ->
+      Report.t list ->
+      Report.t list =
    fun ?(level = Report.Warn) expected actual report ->
     let equal =
-      match (expected, snd actual) with
+      match (expected, actual.t) with
       | _, Any -> true
       | Any, _ -> true
       | String, String -> true
@@ -51,21 +57,21 @@ module Helper = struct
     else
       let message =
         Format.asprintf "The type %a is expected but got %a" pp expected pp
-          (snd actual)
+          actual.t
       in
-      Report.message level (fst actual) message :: report
+      Report.message level actual.pos message :: report
 
   let rec compare_parameter :
       ?level:Report.level ->
       argument ->
-      pos * t ->
+      argument_repr ->
       Report.t list ->
       Report.t list =
    fun ?(level = Report.Warn) expected param report ->
     match expected with
     | Fixed t -> compare ~level t param report
     | Dynamic d ->
-        let type_ = d (snd param) in
+        let type_ = d param.t in
         compare ~level type_ param report
     | Variable c -> compare_parameter ~level c param report
 
@@ -74,7 +80,7 @@ module Helper = struct
       ?level:Report.level ->
       pos ->
       argument list ->
-      (pos * t) list ->
+      argument_repr list ->
       Report.t list ->
       Report.t list =
    fun ?(level = Report.Warn) pos expected actuals report ->
@@ -89,7 +95,7 @@ module Helper = struct
               let check = compare_parameter ~level hd param report in
               (tl, check)
           | [] ->
-              let msg = Report.error (fst param) "Unexpected argument" in
+              let msg = Report.error param.pos "Unexpected argument" in
               ([], msg :: report))
     in
     match tl with
@@ -116,11 +122,11 @@ module Expression = struct
 
   type variable = { pos : pos; name : string; index : repr option }
 
-  let arg_of_repr : t -> pos * Helper.t =
+  let arg_of_repr : t -> Helper.argument_repr =
    fun { result; report; pos; empty } ->
     ignore report;
     ignore empty;
-    (pos, result)
+    { pos; t = result }
 
   (** The variable has type string when starting with a '$' *)
   let ident : variable -> repr =
@@ -245,7 +251,8 @@ module Expression = struct
 
   let boperator : pos -> T.boperator -> repr -> repr -> repr =
    fun pos operator t1 t2 report ->
-    let types = [ arg_of_repr (t1 report); arg_of_repr (t2 report) ] in
+    let t1 = t1 report and t2 = t2 report in
+    let types = [ arg_of_repr t1; arg_of_repr t2 ] in
     match operator with
     | T.Plus ->
         (* Operation over number *)
@@ -253,7 +260,17 @@ module Expression = struct
         let expected = [ d; d ] in
         let report = Helper.compare_args pos expected types report in
         { result = Bool; report; pos; empty = false }
-    | T.Eq | T.Neq | Lt | Gte | Lte | Gt ->
+    | T.Eq | T.Neq ->
+        (* If the expression is '' or 0, we accept the comparaison as if
+            instead of raising a warning *)
+        if t1.empty || t2.empty then
+          { result = Bool; report; pos; empty = false }
+        else
+          let d = Helper.(Dynamic (dyn_type ())) in
+          let expected = [ d; d ] in
+          let report = Helper.compare_args pos expected types report in
+          { result = Bool; report; pos; empty = false }
+    | Lt | Gte | Lte | Gt ->
         let d = Helper.(Dynamic (dyn_type ())) in
         let expected = [ d; d ] in
         let report = Helper.compare_args pos expected types report in