Merge branch 'rinderknecht-dev' into 'dev'

Fixing and adding errors in the parser

See merge request ligolang/ligo!316

gitlab-pages/docs/language-basics/maps-records.md

@@ -82,19 +82,19 @@ If we want to access a move from our moveset above, we can use the `[]` operator
 <!--DOCUSAURUS_CODE_TABS-->
 <!--Pascaligo-->
 ```pascaligo
-const balance: option(move) = moves[("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address)];
+const my_balance : option(move) = moves[("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address)];
 ```
 
 <!--CameLIGO-->
 
 ```cameligo
-let balance: move option = Map.find_opt ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
+let my_balance : move option = Map.find_opt ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
 ```
 
 <!--ReasonLIGO-->
 
 ```reasonligo
-let balance: option(move) =
+let my_balance : option(move) =
   Map.find_opt("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address, moves);
 ```
 <!--END_DOCUSAURUS_CODE_TABS-->
@@ -106,19 +106,19 @@ Accessing a value in a map yields an option, however you can also get the value
 <!--DOCUSAURUS_CODE_TABS-->
 <!--Pascaligo-->
 ```pascaligo
-const balance: move = get_force(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address), moves);
+const my_balance : move = get_force(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address), moves);
 ```
 
 <!--CameLIGO-->
 
 ```cameligo
-let balance: move = Map.find ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
+let my_balance : move = Map.find ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
 ```
 
 <!--ReasonLIGO-->
 
 ```reasonligo
-let balance: move =
+let my_balance : move =
   Map.find("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address, moves);
 ```
 
@@ -341,19 +341,19 @@ If we want to access a move from our moveset above, we can use the `[]` operator
 <!--DOCUSAURUS_CODE_TABS-->
 <!--Pascaligo-->
 ```pascaligo
-const balance: option(move) = moves[("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address)];
+const my_balance : option(move) = moves[("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address)];
 ```
 
 <!--CameLIGO-->
 
 ```cameligo
-let balance: move option = Big_map.find_opt ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
+let my_balance : move option = Big_map.find_opt ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
 ```
 
 <!--ReasonLIGO-->
 
 ```reasonligo
-let balance: option(move) =
+let my_balance : option(move) =
   Big_map.find_opt("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address, moves);
 ```
 <!--END_DOCUSAURUS_CODE_TABS-->
@@ -365,19 +365,19 @@ Accessing a value in a map yields an option, however you can also get the value
 <!--DOCUSAURUS_CODE_TABS-->
 <!--Pascaligo-->
 ```pascaligo
-const balance: move = get_force(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address), moves);
+const my_balance : move = get_force(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address), moves);
 ```
 
 <!--CameLIGO-->
 
 ```cameligo
-let balance: move = Big_map.find ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
+let my_balance : move = Big_map.find ("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address) moves
 ```
 
 <!--ReasonLIGO-->
 
 ```reasonligo
-let balance: move = Big_map.find("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address, moves);
+let my_balance : move = Big_map.find("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN": address, moves);
 ```
 
 <!--END_DOCUSAURUS_CODE_TABS-->

src/passes/1-parser/cameligo/LexToken.mli

@@ -137,12 +137,14 @@ type ident_err = Reserved_name
 type   nat_err = Invalid_natural
                | Non_canonical_zero_nat
 type   sym_err = Invalid_symbol
+type   kwd_err = Invalid_keyword
 
 val mk_int    : lexeme -> Region.t -> (token,   int_err) result
 val mk_nat    : lexeme -> Region.t -> (token,   nat_err) result
 val mk_mutez  : lexeme -> Region.t -> (token,   int_err) result
 val mk_ident  : lexeme -> Region.t -> (token, ident_err) result
 val mk_sym    : lexeme -> Region.t -> (token,   sym_err) result
+val mk_kwd    : lexeme -> Region.t -> (token,   kwd_err) result
 val mk_string : lexeme -> Region.t -> token
 val mk_bytes  : lexeme -> Region.t -> token
 val mk_constr : lexeme -> Region.t -> token

src/passes/1-parser/cameligo/LexToken.mll

@@ -1,4 +1,6 @@
 {
+  (* START HEADER *)
+
 type lexeme = string
 
 let sprintf = Printf.sprintf
@@ -236,8 +238,7 @@ let to_region token = proj_token token |> fst
 
 (* Injections *)
 
-type int_err =
-  Non_canonical_zero
+type int_err = Non_canonical_zero
 
 (* LEXIS *)
 
@@ -258,8 +259,7 @@ let keywords = [
   (fun reg -> Then  reg);
   (fun reg -> True  reg);
   (fun reg -> Type  reg);
-  (fun reg -> With  reg)
-]
+  (fun reg -> With  reg)]
 
 let reserved =
   let open SSet in
@@ -323,8 +323,20 @@ let lexicon : lexis =
       cstr = build constructors;
       res  = reserved}
 
+(* Keywords *)
+
+type kwd_err = Invalid_keyword
+
+let mk_kwd ident region =
+  match SMap.find_opt ident lexicon.kwd with
+    Some mk_kwd -> Ok (mk_kwd region)
+  |        None -> Error Invalid_keyword
+
+(* Identifiers *)
+
 type ident_err = Reserved_name
 
+(* END OF HEADER *)
 }
 
 (* START LEXER DEFINITION *)

src/passes/1-parser/cameligo/ParserMain.ml

@@ -19,9 +19,9 @@ module ExtParserLog =
     include ParserLog
   end
 
-module M = ParserUnit.Make (IO)
-                           (Lexer.Make (LexToken))
-                           (AST)
-                           (ExtParser)
-                           (ParErr)
-                           (ExtParserLog)
+module MyLexer = Lexer.Make (LexToken)
+
+module Unit =
+  ParserUnit.Make (IO)(MyLexer)(AST)(ExtParser)(ParErr)(ExtParserLog)
+
+let () = Unit.run ()

src/passes/1-parser/pascaligo.ml

@@ -5,6 +5,7 @@ module AST = Parser_pascaligo.AST
 module ParserLog = Parser_pascaligo.ParserLog
 module LexToken = Parser_pascaligo.LexToken
 module Lexer = Lexer.Make(LexToken)
+module SyntaxError = Parser_pascaligo.SyntaxError
 
 module Errors = struct
 
@@ -18,6 +19,34 @@ module Errors = struct
     ] in
     error ~data title message
 
+  let reserved_name Region.{value; region} =
+    let title () = Printf.sprintf "reserved name \"%s\"" value in
+    let message () = "" in
+    let data = [
+      ("location",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ region)
+    ] in
+    error ~data title message
+
+  let duplicate_parameter Region.{value; region} =
+    let title () = Printf.sprintf "duplicate parameter \"%s\"" value in
+    let message () = "" in
+    let data = [
+      ("location",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ region)
+    ] in
+    error ~data title message
+
+  let duplicate_variant Region.{value; region} =
+    let title () = Printf.sprintf "duplicate variant \"%s\" in this\
+                                   type declaration" value in
+    let message () = "" in
+    let data = [
+      ("location",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ region)
+    ] in
+    error ~data title message
+
   let parser_error source (start: Lexing.position) (end_: Lexing.position) lexbuf =
     let title () = "parser error" in
     let file = if source = "" then
@@ -82,6 +111,12 @@ let parse (parser: 'a parser) source lexbuf =
     try
       ok (parser read lexbuf)
     with
+      SyntaxError.Error (Duplicate_parameter name) ->
+        fail @@ (duplicate_parameter name)
+    | SyntaxError.Error (Duplicate_variant name) ->
+        fail @@ (duplicate_variant name)
+    | SyntaxError.Error (Reserved_name name) ->
+        fail @@ (reserved_name name)
     | Parser.Error ->
         let start = Lexing.lexeme_start_p lexbuf in
         let end_ = Lexing.lexeme_end_p lexbuf in

src/passes/1-parser/pascaligo/AST.ml

@@ -761,3 +761,48 @@ let rhs_to_region = expr_to_region
 let selection_to_region = function
   FieldName {region; _}
   | Component {region; _} -> region
+
+(* Extracting variables from patterns *)
+
+module Ord =
+  struct
+    type t = string Region.reg
+    let compare v1 v2 =
+      compare v1.value v2.value
+  end
+
+module VSet = Set.Make (Ord)
+
+let rec vars_of_pattern env = function
+  PConstr p -> vars_of_pconstr env p
+| PVar v -> VSet.add v env
+| PWild _ | PInt _ | PNat _ | PBytes _ | PString _ -> env
+| PList l -> vars_of_plist env l
+| PTuple t -> vars_of_ptuple env t.value
+
+and vars_of_pconstr env = function
+  PUnit _ | PFalse _ | PTrue _ | PNone _ -> env
+| PSomeApp {value=_, {value={inside; _};_}; _} ->
+    vars_of_pattern env inside
+| PConstrApp {value=_, Some tuple; _} ->
+    vars_of_ptuple env tuple.value
+| PConstrApp {value=_,None; _} -> env
+
+and vars_of_plist env = function
+  PListComp {value; _} ->
+    vars_of_pinj env value
+| PNil _ ->
+    env
+| PParCons {value={inside; _}; _} ->
+   let head, _, tail = inside in
+   vars_of_pattern (vars_of_pattern env head) tail
+| PCons {value; _} ->
+    Utils.nsepseq_foldl vars_of_pattern env value
+
+and vars_of_pinj env inj =
+  Utils.sepseq_foldl vars_of_pattern env inj.elements
+
+and vars_of_ptuple env {inside; _} =
+    Utils.nsepseq_foldl vars_of_pattern env inside
+
+let vars_of_pattern = vars_of_pattern VSet.empty

src/passes/1-parser/pascaligo/AST.mli

@@ -615,3 +615,9 @@ val lhs_to_region        : lhs -> Region.t
 val rhs_to_region        : rhs -> Region.t
 val if_clause_to_region  : if_clause -> Region.t
 val selection_to_region  : selection -> Region.t
+
+(* Extracting variables from patterns *)
+
+module VSet : Set.S with type elt = string Region.reg
+
+val vars_of_pattern : pattern -> VSet.t

src/passes/1-parser/pascaligo/LexToken.mli

@@ -138,12 +138,14 @@ type ident_err = Reserved_name
 type   nat_err = Invalid_natural
                | Non_canonical_zero_nat
 type   sym_err = Invalid_symbol
+type   kwd_err = Invalid_keyword
 
 val mk_int    : lexeme -> Region.t -> (token,   int_err) result
 val mk_nat    : lexeme -> Region.t -> (token,   nat_err) result
 val mk_mutez  : lexeme -> Region.t -> (token,   int_err) result
 val mk_ident  : lexeme -> Region.t -> (token, ident_err) result
 val mk_sym    : lexeme -> Region.t -> (token,   sym_err) result
+val mk_kwd    : lexeme -> Region.t -> (token,   kwd_err) result
 val mk_string : lexeme -> Region.t -> token
 val mk_bytes  : lexeme -> Region.t -> token
 val mk_constr : lexeme -> Region.t -> token

src/passes/1-parser/pascaligo/LexToken.mll

@@ -389,6 +389,15 @@ let lexicon : lexis =
       cstr = build constructors;
       res  = reserved}
 
+(* Keywords *)
+
+type kwd_err = Invalid_keyword
+
+let mk_kwd ident region =
+  match SMap.find_opt ident lexicon.kwd with
+    Some mk_kwd -> Ok (mk_kwd region)
+  |        None -> Error Invalid_keyword
+
 (* Identifiers *)
 
 type ident_err = Reserved_name

src/passes/1-parser/pascaligo/Parser.mly

@@ -6,6 +6,59 @@
 open Region
 open AST
 
+module SSet = Utils.String.Set
+
+let reserved =
+  let open SSet in
+  empty
+  |> add "get_force"
+  |> add "get_chain_id"
+  |> add "transaction"
+  |> add "get_contract"
+  |> add "get_entrypoint"
+  |> add "size"
+  |> add "int"
+  |> add "abs"
+  |> add "is_nat"
+  |> add "amount"
+  |> add "balance"
+  |> add "now"
+  |> add "unit"
+  |> add "source"
+  |> add "sender"
+  |> add "failwith"
+  |> add "bitwise_or"
+  |> add "bitwise_and"
+  |> add "bitwise_xor"
+  |> add "string_concat"
+  |> add "string_slice"
+  |> add "crypto_check"
+  |> add "crypto_hash_key"
+  |> add "bytes_concat"
+  |> add "bytes_slice"
+  |> add "bytes_pack"
+  |> add "bytes_unpack"
+  |> add "set_empty"
+  |> add "set_mem"
+  |> add "set_add"
+  |> add "set_remove"
+  |> add "set_iter"
+  |> add "set_fold"
+  |> add "list_iter"
+  |> add "list_fold"
+  |> add "list_map"
+  |> add "map_iter"
+  |> add "map_map"
+  |> add "map_fold"
+  |> add "map_remove"
+  |> add "map_update"
+  |> add "map_get"
+  |> add "map_mem"
+  |> add "sha_256"
+  |> add "sha_512"
+  |> add "blake2b"
+  |> add "cons"
+
  (* END HEADER *)
 %}
 
@@ -118,6 +171,10 @@ declaration:
 
 type_decl:
   "type" type_name "is" type_expr ";"? {
+    let () =
+      if SSet.mem $2.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $2)) in
     let stop =
       match $5 with
         Some region -> region
@@ -185,6 +242,14 @@ type_tuple:
 
 sum_type:
   "|"? nsepseq(variant,"|") {
+    let add acc {value; _} =
+      if VSet.mem value.constr acc then
+        let open! SyntaxError in
+        raise (Error (Duplicate_variant value.constr))
+      else VSet.add value.constr acc in
+    let variants =
+      Utils.nsepseq_foldl add VSet.empty $2 in
+    let () = ignore variants in
     let region = nsepseq_to_region (fun x -> x.region) $2
     in TSum {region; value=$2} }
 
@@ -225,6 +290,13 @@ fun_expr:
   "function" fun_name? parameters ":" type_expr "is"
      block
   "with" expr {
+    let () =
+      match $2 with
+        Some name ->
+          if SSet.mem name.value reserved then
+            let open! SyntaxError in
+            raise (Error (Reserved_name name))
+      | None -> () in
     let stop   = expr_to_region $9 in
     let region = cover $1 stop
     and value  = {kwd_function = $1;
@@ -237,6 +309,13 @@ fun_expr:
                   return       = $9}
     in {region; value} }
 | "function" fun_name? parameters ":" type_expr "is" expr {
+    let () =
+      match $2 with
+        Some name ->
+          if SSet.mem name.value reserved then
+            let open! SyntaxError in
+            raise (Error (Reserved_name name))
+      | None -> () in
     let stop   = expr_to_region $7 in
     let region = cover $1 stop
     and value  = {kwd_function = $1;
@@ -266,10 +345,31 @@ open_fun_decl:
     in {region; value} }
 
 parameters:
-  par(nsepseq(param_decl,";")) { $1 }
+  par(nsepseq(param_decl,";")) {
+    let open! AST in
+    let contents : (param_decl, semi) Utils.nsepseq par reg = $1 in
+    let add acc = function
+      ParamConst {value; _} ->
+        if VSet.mem value.var acc then
+          let open! SyntaxError in
+          raise (Error (Duplicate_parameter value.var))
+        else VSet.add value.var acc
+    | ParamVar {value; _} ->
+        if VSet.mem value.var acc then
+          let open! SyntaxError in
+          raise (Error (Duplicate_parameter value.var))
+        else VSet.add value.var acc in
+    let params =
+      Utils.nsepseq_foldl add VSet.empty contents.value.inside in
+    let () = ignore params
+    in $1 }
 
 param_decl:
   "var" var ":" param_type {
+    let () =
+      if SSet.mem $2.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $2)) in
     let stop   = type_expr_to_region $4 in
     let region = cover $1 stop
     and value  = {kwd_var    = $1;
@@ -279,6 +379,10 @@ param_decl:
     in ParamVar {region; value}
   }
 | "const" var ":" param_type {
+    let () =
+      if SSet.mem $2.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $2)) in
     let stop   = type_expr_to_region $4 in
     let region = cover $1 stop
     and value  = {kwd_const  = $1;
@@ -346,13 +450,16 @@ open_var_decl:
 
 unqualified_decl(OP):
   var ":" type_expr OP expr {
+    let () =
+      if SSet.mem $1.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $1)) in
     let region = expr_to_region $5
     in $1, $2, $3, $4, $5, region }
 
 const_decl:
-  open_const_decl { $1 }
-| open_const_decl ";" {
-    {$1 with value = {$1.value with terminator = Some $2}} }
+  open_const_decl ";"? {
+    {$1 with value = {$1.value with terminator=$2}} }
 
 instruction:
   conditional  {        Cond $1 }
@@ -555,6 +662,14 @@ cases(rhs):
 
 case_clause(rhs):
   pattern "->" rhs {
+    let vars = AST.vars_of_pattern $1 in
+    let is_reserved elt = SSet.mem elt.value reserved in
+    let inter = VSet.filter is_reserved vars in
+    let () =
+      if not (VSet.is_empty inter) then
+        let clash = VSet.choose inter in
+        let open! SyntaxError in
+        raise (Error (Reserved_name clash)) in
     fun rhs_to_region ->
       let start  = pattern_to_region $1 in
       let region = cover start (rhs_to_region $3)
@@ -596,6 +711,10 @@ for_loop:
     in For (ForInt {region; value})
   }
 | "for" var arrow_clause? "in" collection expr block {
+    let () =
+      if SSet.mem $2.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $2)) in
     let region = cover $1 $7.region in
     let value  = {kwd_for    = $1;
                   var        = $2;
@@ -613,12 +732,21 @@ collection:
 
 var_assign:
   var ":=" expr {
+    let () =
+      if SSet.mem $1.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $1)) in
     let region = cover $1.region (expr_to_region $3)
     and value  = {name=$1; assign=$2; expr=$3}
     in {region; value} }
 
 arrow_clause:
-  "->" var { $1,$2 }
+  "->" var {
+    let () =
+      if SSet.mem $2.value reserved then
+        let open! SyntaxError in
+        raise (Error (Reserved_name $2))
+    in $1,$2 }
 
 (* Expressions *)
 

src/passes/1-parser/pascaligo/ParserMain.ml

@@ -19,9 +19,55 @@ module ExtParserLog =
     include ParserLog
   end
 
-module M = ParserUnit.Make (IO)
-                           (Lexer.Make (LexToken))
-                           (AST)
-                           (ExtParser)
-                           (ParErr)
-                           (ExtParserLog)
+module MyLexer = Lexer.Make (LexToken)
+
+module Unit =
+  ParserUnit.Make (IO)(MyLexer)(AST)(ExtParser)(ParErr)(ExtParserLog)
+
+open! SyntaxError
+
+let () =
+  try Unit.run () with
+    (* Ad hoc errors from the parser *)
+
+    Error (Reserved_name name) ->
+      let () = Unit.close_all () in
+      let token =
+        MyLexer.Token.mk_ident name.Region.value name.Region.region in
+      (match token with
+         Stdlib.Error _ ->
+           assert false (* Should not fail if [name] is valid. *)
+       | Ok invalid ->
+           let point = "Reserved name.\nHint: Change the name.\n",
+                       None, invalid in
+           let error =
+             Unit.format_error ~offsets:IO.options#offsets
+                               IO.options#mode point
+           in Printf.eprintf "\027[31m%s\027[0m%!" error)
+
+  | Error (Duplicate_parameter name) ->
+      let () = Unit.close_all () in
+      let token =
+        MyLexer.Token.mk_ident name.Region.value name.Region.region in
+      (match token with
+         Stdlib.Error _ ->
+           assert false (* Should not fail if [name] is valid. *)
+       | Ok invalid ->
+           let point = "Duplicate parameter.\nHint: Change the name.\n",
+                       None, invalid in
+           let error =
+             Unit.format_error ~offsets:IO.options#offsets
+                               IO.options#mode point
+           in Printf.eprintf "\027[31m%s\027[0m%!" error)
+
+  | Error (Duplicate_variant name) ->
+      let () = Unit.close_all () in
+      let token =
+        MyLexer.Token.mk_constr name.Region.value name.Region.region in
+      let point = "Duplicate variant in this type declaration.\n\
+                   Hint: Change the name.\n",
+                  None, token in
+      let error =
+        Unit.format_error ~offsets:IO.options#offsets
+                          IO.options#mode point
+      in Printf.eprintf "\027[31m%s\027[0m%!" error

src/passes/1-parser/pascaligo/SyntaxError.ml

@@ -0,0 +1,8 @@
+type t =
+  Reserved_name of string Region.reg
+| Duplicate_parameter of string Region.reg
+| Duplicate_variant of string Region.reg
+
+type error = t
+
+exception Error of t

src/passes/1-parser/pascaligo/SyntaxError.mli

@@ -0,0 +1,8 @@
+type t =
+  Reserved_name of string Region.reg
+| Duplicate_parameter of string Region.reg
+| Duplicate_variant of string Region.reg
+
+type error = t
+
+exception Error of t

src/passes/1-parser/pascaligo/dune

@@ -8,7 +8,8 @@
 (library
  (name parser_pascaligo)
  (public_name ligo.parser.pascaligo)
- (modules AST pascaligo Parser ParserLog LexToken)
+ (modules
+    SyntaxError AST pascaligo Parser ParserLog LexToken)
  (libraries
     menhirLib
     parser_shared

src/passes/1-parser/reasonligo/LexToken.mli

@@ -135,15 +135,17 @@ type ident_err = Reserved_name
 type   nat_err = Invalid_natural
                | Non_canonical_zero_nat
 type   sym_err = Invalid_symbol
+type   kwd_err = Invalid_keyword
 
-val mk_string : lexeme -> Region.t -> token
-val mk_bytes  : lexeme -> Region.t -> token
 val mk_int    : lexeme -> Region.t -> (token,   int_err) result
 val mk_nat    : lexeme -> Region.t -> (token,   nat_err) result
 val mk_mutez  : lexeme -> Region.t -> (token,   int_err) result
 val mk_ident  : lexeme -> Region.t -> (token, ident_err) result
-val mk_constr : lexeme -> Region.t -> token
 val mk_sym    : lexeme -> Region.t -> (token,   sym_err) result
+val mk_kwd    : lexeme -> Region.t -> (token,   kwd_err) result
+val mk_string : lexeme -> Region.t -> token
+val mk_bytes  : lexeme -> Region.t -> token
+val mk_constr : lexeme -> Region.t -> token
 val eof       : Region.t -> token
 
 (* Predicates *)

src/passes/1-parser/reasonligo/LexToken.mll

@@ -1,4 +1,6 @@
 {
+(* START OF HEADER *)
+
 type lexeme = string
 
 let sprintf = Printf.sprintf
@@ -91,10 +93,11 @@ type t =
 
 | EOF of Region.t (* End of file *)
 
+
 type token = t
 
 let proj_token = function
-  | CAT region -> region, "CAT"
+  CAT region -> region, "CAT"
 | MINUS region -> region, "MINUS"
 | PLUS region -> region, "PLUS"
 | SLASH region -> region, "SLASH"
@@ -153,7 +156,7 @@ let proj_token = function
 | EOF region -> region, "EOF"
 
 let to_lexeme = function
-  | CAT _ -> "++"
+  CAT _ -> "++"
 | MINUS _ -> "-"
 | PLUS _ -> "+"
 | SLASH _ -> "/"
@@ -216,6 +219,7 @@ type ident_err = Reserved_name
 type   nat_err = Invalid_natural
                | Non_canonical_zero_nat
 type   sym_err = Invalid_symbol
+type   kwd_err = Invalid_keyword
 
 (* LEXIS *)
 
@@ -228,8 +232,7 @@ let keywords = [
   (fun reg -> Mod    reg);
   (fun reg -> Or     reg);
   (fun reg -> True   reg);
-  (fun reg -> Type  reg);
-]
+  (fun reg -> Type   reg)]
 
 (* See: http://caml.inria.fr/pub/docs/manual-ocaml/lex.html#sec86 and
    https://github.com/facebook/reason/blob/master/src/reason-parser/reason_parser.mly *)
@@ -305,6 +308,14 @@ let lexicon : lexis =
       cstr = build constructors;
       res  = reserved}
 
+(* Keywords *)
+
+let mk_kwd ident region =
+  match SMap.find_opt ident lexicon.kwd with
+    Some mk_kwd -> Ok (mk_kwd region)
+  |        None -> Error Invalid_keyword
+
+(* END OF HEADER *)
 }
 
 (* START LEXER DEFINITION *)
@@ -380,6 +391,8 @@ let mk_mutez lexeme region =
 
 let eof region = EOF region
 
+(* Making symbols *)
+
 let mk_sym lexeme region =
   match lexeme with
     "-"  -> Ok (MINUS     region)
@@ -408,13 +421,18 @@ let mk_sym lexeme region =
   | ")"  -> Ok (RPAR      region)
 
   (* Symbols specific to ReasonLIGO *)
+
   | "..." ->  Ok (ELLIPSIS  region)
   | "=>"  ->  Ok (ARROW     region)
   | "=="  ->  Ok (EQEQ      region)
   | "!"   ->  Ok (NOT       region)
   | "++"  ->  Ok (CAT       region)
+
+  (* Invalid symbols *)
+
   |     _ ->  Error Invalid_symbol
 
+
 (* Identifiers *)
 
 let mk_ident' lexeme region lexicon =
@@ -448,7 +466,7 @@ let is_ident = function
 |       _ -> false
 
 let is_kwd = function
-  | Else _
+  Else _
 | False _
 | If _
 | Let _
@@ -456,18 +474,18 @@ let is_kwd = function
 | Mod _
 | Or _
 | True _
-  | Type _
+| Type _ -> true
 | _ -> false
 
 let is_constr = function
-| Constr  _
+  Constr _
 | Ident _
 | False _
 | True _ -> true
 | _ -> false
 
 let is_sym = function
-| CAT _
+  CAT _
 | MINUS _
 | PLUS _
 | SLASH _

src/passes/1-parser/reasonligo/Parser.mly

@@ -370,7 +370,7 @@ ptuple:
     in PTuple {value=$1; region} }
 
 unit:
-  "(" ")" { {region = cover $1 $2; value = ghost, ghost} }
+  "(" ")" { {region = cover $1 $2; value = $1, $2} }
 
 (* Expressions *)
 

src/passes/1-parser/reasonligo/ParserMain.ml

@@ -19,9 +19,26 @@ module ExtParserLog =
     include ParserLog
   end
 
-module M = ParserUnit.Make (IO)
-                           (Lexer.Make (LexToken))
-                           (AST)
-                           (ExtParser)
-                           (ParErr)
-                           (ExtParserLog)
+module MyLexer = Lexer.Make (LexToken)
+
+module Unit =
+  ParserUnit.Make (IO)(MyLexer)(AST)(ExtParser)(ParErr)(ExtParserLog)
+
+(* Main *)
+
+let () =
+  try Unit.run () with
+    (* Ad hoc errors from the parsers *)
+
+    SyntaxError.Error (SyntaxError.WrongFunctionArguments expr) ->
+      let () = Unit.close_all () in
+      let msg = "It looks like you are defining a function, \
+                 however we do not\n\
+                 understand the parameters declaration.\n\
+                 Examples of valid functions:\n\
+                 let x = (a: string, b: int) : int => 3;\n\
+                 let x = (a: string) : string => \"Hello, \" ++ a;\n"
+      and reg = AST.expr_to_region expr in
+      let error = Unit.short_error ~offsets:IO.options#offsets
+                                   IO.options#mode msg reg
+      in Printf.eprintf "\027[31m%s\027[0m%!" error

src/passes/1-parser/shared/ParserAPI.ml

@@ -1,5 +1,7 @@
 (* Generic parser for LIGO *)
 
+module Region = Simple_utils.Region
+
 module type PARSER =
   sig
     (* The type of tokens, abstract syntax trees and expressions *)
@@ -117,4 +119,9 @@ module Make (Lexer: Lexer.S)
       let header = header ^ trailer in
       header ^ (if msg = "" then ".\n" else ":\n" ^ msg)
 
+    let short_error ?(offsets=true) mode msg (invalid_region: Region.t) =
+      let () = assert (not (invalid_region#is_ghost)) in
+      let header =
+        "Parse error " ^ invalid_region#to_string ~offsets mode in
+      header ^ (if msg = "" then ".\n" else ":\n" ^ msg)
   end

src/passes/1-parser/shared/ParserAPI.mli

@@ -1,5 +1,7 @@
 (* Generic parser API for LIGO *)
 
+module Region = Simple_utils.Region
+
 module type PARSER =
   sig
     (* The type of tokens. *)
@@ -56,5 +58,9 @@ module Make (Lexer: Lexer.S)
 
     exception Point of error
 
-    val format_error : ?offsets:bool -> [`Byte | `Point] -> error -> string
+    val format_error :
+      ?offsets:bool -> [`Byte | `Point] -> error -> string
+
+    val short_error :
+      ?offsets:bool -> [`Byte | `Point] -> message -> Region.t -> string
   end

src/passes/1-parser/shared/ParserUnit.ml

@@ -14,7 +14,8 @@ module type Pretty =
       state -> ast -> unit
     val mk_state :
       offsets:bool -> mode:[`Point|`Byte] -> buffer:Buffer.t -> state
-    val print_tokens : state -> ast -> unit
+    val print_tokens :
+      state -> ast -> unit
   end
 
 module Make (IO: S)
@@ -85,6 +86,9 @@ module Make (IO: S)
 
     module ParserFront = ParserAPI.Make (Lexer) (Parser) (ParErr)
 
+    let format_error = ParserFront.format_error
+    let short_error = ParserFront.short_error
+
     let lexer_inst = Lexer.open_token_stream (Some pp_input)
     let Lexer.{read; buffer; get_win; get_pos; get_last; close} = lexer_inst
 
@@ -103,7 +107,7 @@ module Make (IO: S)
 
     (* Main *)
 
-    let () =
+    let run () =
       try
         let ast =
           if   IO.options#mono
@@ -131,6 +135,7 @@ module Make (IO: S)
              end
       with
         (* Lexing errors *)
+
         Lexer.Error err ->
           close_all ();
           let msg =
@@ -139,6 +144,7 @@ module Make (IO: S)
           in prerr_string msg
 
       (* Incremental API of Menhir *)
+
       | ParserFront.Point point ->
           let () = close_all () in
           let error =
@@ -147,6 +153,7 @@ module Make (IO: S)
           in eprintf "\027[31m%s\027[0m%!" error
 
       (* Monolithic API of Menhir *)
+
       | Parser.Error ->
           let () = close_all () in
           let invalid, valid_opt =
@@ -162,6 +169,7 @@ module Make (IO: S)
           in eprintf "\027[31m%s\027[0m%!" error
 
       (* I/O errors *)
+
       | Sys_error msg -> Utils.highlight msg
 
   end

src/test/contracts/chain_id.ligo

@@ -1,5 +1,5 @@
 
-function get_chain_id (const tt : chain_id) : chain_id is
+function chain_id (const tt : chain_id) : chain_id is
   block {
     var toto : chain_id := get_chain_id ;
   } with ( toto )

src/test/integration_tests.ml

@@ -1759,7 +1759,7 @@ let chain_id () : unit result =
     Tezos_base__TzPervasives.Chain_id.zero in
   let make_input = e_chain_id pouet in
   let make_expected = e_chain_id pouet in
-  let%bind () = expect_eq program "get_chain_id" make_input make_expected in
+  let%bind () = expect_eq program "chain_id" make_input make_expected in
   ok ()
 
 let key_hash () : unit result =