3 files changed, 37 insertions, 14 deletions
diff --git a/lib/syntax/S.ml b/lib/syntax/S.ml
index 63fcd08..6bdbc9d 100644
--- a/lib/syntax/S.ml
+++ b/lib/syntax/S.ml
@@ -19,7 +19,8 @@ type ('a, 'b) variable = { pos : 'a; name : string; index : 'b option }
 (** Represent the evaluation over an expression *)
 module type Expression = sig
   type 'a obs
-  type repr
+  type t
+  type repr = Report.t list -> t * Report.t list
 
   type variable = { pos : pos; name : string; index : repr option }
   (** 
diff --git a/lib/syntax/tree.ml b/lib/syntax/tree.ml
index ecad1b4..51033a1 100644
--- a/lib/syntax/tree.ml
+++ b/lib/syntax/tree.ml
@@ -1,3 +1,5 @@
+open StdLabels
+
 type pos = Lexing.position * Lexing.position
 
 module Ast = struct
@@ -34,25 +36,34 @@ module Ast = struct
 end
 
 (** Default implementation for the expression *)
-module Expression : S.Expression with type repr = pos Ast.expression = struct
+module Expression : S.Expression with type t = pos Ast.expression = struct
   type 'a obs
-  type repr = pos Ast.expression
+  type t = pos Ast.expression
+  type repr = Report.t list -> t * Report.t list
   type variable = { pos : pos; name : string; index : repr option }
 
-  let integer : pos -> string -> repr = fun pos i -> Ast.Integer (pos, i)
-  let literal : pos -> string -> repr = fun pos l -> Ast.Literal (pos, l)
+  let integer : pos -> string -> repr = fun pos i r -> (Ast.Integer (pos, i), r)
+  let literal : pos -> string -> repr = fun pos l r -> (Ast.Literal (pos, l), r)
 
   let function_ : pos -> T.function_ -> repr list -> repr =
-   fun pos name args -> Ast.Function (pos, name, args)
+   fun pos name args r ->
+    let args = List.map ~f:(fun f -> fst (f r)) args in
+    (Ast.Function (pos, name, args), r)
 
   let uoperator : pos -> T.uoperator -> repr -> repr =
-   fun pos op expression -> Ast.Op (pos, op, expression)
+   fun pos op expression r ->
+    let expression = fst (expression r) in
+    (Ast.Op (pos, op, expression), r)
 
   let boperator : pos -> T.boperator -> repr -> repr -> repr =
-   fun pos op op1 op2 -> Ast.BinaryOp (pos, op, op1, op2)
+   fun pos op op1 op2 r ->
+    let op1 = fst (op1 r) and op2 = fst (op2 r) in
+    (Ast.BinaryOp (pos, op, op1, op2), r)
 
   let ident : variable -> repr =
-   fun { pos; name; index } -> Ast.Ident { pos; name; index }
+   fun { pos; name; index } r ->
+    let index = Option.map (fun i -> fst (i r)) index in
+    (Ast.Ident { pos; name; index }, r)
 end
 
 module Instruction :
@@ -65,25 +76,36 @@ module Instruction :
   type variable = Expression.variable
 
   let call : pos -> T.keywords -> expression list -> repr =
-   fun pos name args -> Ast.Call (pos, name, args)
+   fun pos name args ->
+    let args = List.map ~f:(fun f -> fst (f [])) args in
+    Ast.Call (pos, name, args)
 
   let location : pos -> string -> repr =
    fun loc label -> Ast.Location (loc, label)
 
   let comment : pos -> repr = fun pos -> Ast.Comment pos
-  let expression : expression -> repr = fun expr -> Ast.Expression expr
+
+  let expression : expression -> repr =
+   fun expr -> Ast.Expression (fst (expr []))
 
   type clause = pos * expression * repr list
 
   let if_ : pos -> clause -> elifs:clause list -> else_:repr list -> repr =
    fun pos predicate ~elifs ~else_ ->
-    Ast.If { loc = pos; then_ = predicate; elifs; else_ }
+    let clause (pos, expr, repr) = (pos, fst (expr []), repr) in
+    let elifs = List.map ~f:clause elifs in
+
+    Ast.If { loc = pos; then_ = clause predicate; elifs; else_ }
 
   let act : pos -> label:expression -> repr list -> repr =
-   fun pos ~label statements -> Ast.Act { loc = pos; label; statements }
+   fun pos ~label statements ->
+    let label = fst (label []) in
+    Ast.Act { loc = pos; label; statements }
 
   let assign : pos -> variable -> T.assignation_operator -> expression -> repr =
    fun pos_loc { pos; name; index } op expr ->
+    let index = Option.map (fun i -> fst (i [])) index
+    and expr = fst (expr []) in
     Ast.Declaration (pos_loc, { pos; name; index }, op, expr)
 end
 
diff --git a/lib/syntax/tree.mli b/lib/syntax/tree.mli
index ad052e9..c54a9ff 100644
--- a/lib/syntax/tree.mli
+++ b/lib/syntax/tree.mli
@@ -46,6 +46,6 @@ end
 
 include
   S.Analyzer
-    with type Expression.repr = Ast.pos Ast.expression
+    with type Expression.t = Ast.pos Ast.expression
      and type Instruction.repr = Ast.pos Ast.statement
      and type Location.repr = Ast.pos * Ast.pos Ast.statement list