diff --git a/lib/eval.ml b/lib/eval.ml
index b958f2f..5b0cff3 100644
--- a/lib/eval.ml
+++ b/lib/eval.ml
@@ -94,7 +94,6 @@ and eval_bin_op_expr scope op left_expr right_expr =
 
 let eval_str (str: string): value_type = 
   let tokens = Lexer.lex_tokens_seq str in
-  let tokens = tokens |> Seq.map (fun (x,_) -> x) in
   let expr = Parser.get_expr_tree_from_tokens tokens in
   match expr with
   | Some e -> eval_expr { parent = None; bindings = VariableBindingMap.empty } e
diff --git a/lib/lexer.ml b/lib/lexer.ml
index df0f498..30c82fe 100644
--- a/lib/lexer.ml
+++ b/lib/lexer.ml
@@ -257,7 +257,7 @@ let%test "test lex_token 2" =
 let lex_tokens_seq (total: string): (token * lexer_context) Seq.t = 
   let rec aux ctx = 
     let token, next_ctx = lex_token ctx in
-    if token.token_type = Eof then 
+    if token.token_type = Eof then
       Seq.Cons ((token, next_ctx), fun () -> Seq.Nil)
     else
       Seq.Cons ((token, next_ctx), fun () -> aux next_ctx) in
diff --git a/lib/parser.ml b/lib/parser.ml
index d0ff5ae..3b5dec1 100644
--- a/lib/parser.ml
+++ b/lib/parser.ml
@@ -1,7 +1,7 @@
 open Lexer
 
 type parser_context = {
-  seq: Lexer.token Seq.t;
+  seq: (Lexer.token * Lexer.lexer_context) Seq.t;
   errors: string list;
 }
 
@@ -33,10 +33,10 @@ let or_parser (a: 'a parser) (b: 'a parser): 'a parser = fun (ctx: parser_contex
 let (<|>) = or_parser
 
 let peek_token: token parser = fun (ctx: parser_context) -> 
-  Seq.uncons ctx.seq |> Option.map (fun (t,_) -> (t,ctx))
+  Seq.uncons ctx.seq |> Option.map (fun ((t, _),_) -> (t,ctx))
 
 let next_token: token parser = fun (ctx: parser_context) -> 
-  Seq.uncons ctx.seq |> Option.map (fun (t, s) -> (t, 
+  Seq.uncons ctx.seq |> Option.map (fun ((t,_), s) -> (t, 
   { ctx with seq = s}
 ))
 
@@ -201,8 +201,8 @@ and expr (): expr_tree parser =
     (parse_if_expr() |> fmap (fun x -> IfExpr x)) <|> parse_level3() in
   return e
 
-let get_expr_tree_from_tokens (tokens: Lexer.token Seq.t): expr_tree option =
-  let ntokens = Seq.filter (fun x -> 
+let get_expr_tree_from_tokens (tokens: (Lexer.token * Lexer.lexer_context) Seq.t): expr_tree option =
+  let ntokens = Seq.filter (fun (x,_) -> 
     match x.token_type with 
     | Lexer.Comment(_) -> false 
     | _ -> true
@@ -214,7 +214,6 @@ let get_expr_tree_from_tokens (tokens: Lexer.token Seq.t): expr_tree option =
 
 let%test "test get_expr_tree_from_tokens 1" =
   let tokens = Lexer.lex_tokens_seq "let x = 1 in\n  x" in
-  let tokens = tokens |> Seq.map (fun (x,_) -> x) in
   match get_expr_tree_from_tokens tokens with
   | Some e -> expr2str e = "let x = 1 in\n  x"
   | None -> false