Merge branch 'feature/pascaligo-anon-functions' into 'dev'

Feature/pascaligo anon functions

See merge request ligolang/ligo!201

gitlab-pages/docs/language-basics/functions.md

@@ -36,7 +36,9 @@ Here's how you define a basic function that accepts two `ints` and returns a sin
 
 ```pascaligo
 function add(const a: int; const b: int): int is 
-    block { skip } with a + b
+    begin
+        const result: int = a + b;
+    end with result;
 ```
 
 The function body consists of two parts:
@@ -44,9 +46,14 @@ The function body consists of two parts:
 - `block {<code>}` - logic of the function
 - `with <value>` - the return value of the function
 
-> 💡 `skip` can be used as a placeholder for empty function blocks, when all the neccessary logic fits into `with` at the end. It is also possible to omit `block { skip } with`
-in the above example, leaving only `a + b`.
+#### Blockless functions
 
+Functions that can contain all of their logic into a single instruction/expression, can be defined without the surrounding `block`.
+Instead, you can inline the necessary logic directly, like this:
+
+```pascaligo
+function add(const a: int; const b: int): int is a + b
+```
 
 <!--Cameligo-->
 
@@ -65,3 +72,25 @@ value.
 
 <!--END_DOCUSAURUS_CODE_TABS-->
 
+<!--DOCUSAURUS_CODE_TABS-->
+<!--Pascaligo-->
+```pascaligo
+const increment : (int -> int) = (function (const i : int) : int is i + 1);
+// a = 2
+const a: int = increment(1);
+```
+<!--END_DOCUSAURUS_CODE_TABS-->
+
+## Anonymous functions
+
+Functions without a name, also known as anonymous functions are useful in cases when you want to pass the function as an argument or assign it to a key in a record/map.
+
+Here's how to define an anonymous function assigned to a variable `increment`, with it's appropriate function type signature.
+<!--DOCUSAURUS_CODE_TABS-->
+<!--Pascaligo-->
+```pascaligo
+const increment : (int -> int) = (function (const i : int) : int is i + 1);
+// a = 2
+const a: int = increment(1);
+```
+<!--END_DOCUSAURUS_CODE_TABS-->

gitlab-pages/docs/language-basics/src/functions/add.ligo

@@ -0,0 +1,4 @@
+function add(const a: int; const b: int): int is 
+    begin
+        const result: int = a + b;
+    end with result;

gitlab-pages/docs/language-basics/src/functions/anon.ligo

@@ -0,0 +1,3 @@
+const increment : (int -> int) = (function (const i : int) : int is i + 1);
+// a = 2
+const a: int = increment(1);

gitlab-pages/docs/language-basics/src/functions/blockless.ligo

@@ -0,0 +1 @@
+function add(const a: int; const b: int): int is a + b

gitlab-pages/docs/language-basics/variables-and-constants.md

@@ -43,6 +43,9 @@ Variables, unlike constants, are mutable. They can't be used in a *global scope*
 
 > 💡 Don't worry if you don't understand the function syntax yet. We'll get to it in upcoming sections of the docs.
 
+> ⚠️ Please be wary that mutation only works within the function scope itself, values outside of the function scope will not be affected.
+
+
 
 ```pascaligo
 // won't work, use const for global values instead

gitlab-pages/website/pages/en/index.js

@@ -18,55 +18,25 @@ const GridBlock = CompLibrary.GridBlock;
 const pre = "```";
 
 const pascaligoExampleSmall = `${pre}pascaligo
-// variant defining pseudo multi-entrypoint 
-// actions
-type action is
-| Increment of int
-| Decrement of int
-
-function add 
-  (const a: int; const b: int): int is 
-  block { skip } with a + b
-
-function subtract 
-  (const a: int; const b: int): int 
-  is block { skip } with a - b
-
-// real entrypoint that re-routes the flow 
-// based on the action provided
-function main 
-  (const p: action; const s: int): 
-  (list(operation) * int) is
- block { skip } 
-  with ((nil : list(operation)),
-    case p of
-    | Increment(n) -> add(s, n)
-    | Decrement(n) -> subtract(s, n)
-  end)
-${pre}`;
-
-const pascaligoExample = `${pre}pascaligo
 // variant defining pseudo multi-entrypoint actions
 type action is
 | Increment of int
 | Decrement of int
 
-function add (const a : int ; const b : int) : int is
- block { skip } with a + b
+function add (const a : int ; const b : int) : int is a + b
 
-function subtract (const a : int ; const b : int) : int is
- block { skip } with a - b
+function subtract (const a : int ; const b : int) : int is a - b
 
-// real entrypoint that re-routes the flow based 
-// on the action provided
-function main (const p : action ; const s : int) : 
-  (list(operation) * int) is
- block { skip } with ((nil : list(operation)),
+// real entrypoint that re-routes the flow based on the action provided
+function main (const p : action ; const s : int) : (list(operation) * int) is 
+  ((nil : list(operation)),
     case p of
     | Increment (n) -> add (s, n)
     | Decrement (n) -> subtract (s, n)
     end)
 ${pre}`;
+
+const pascaligoExample = pascaligoExampleSmall;
 const cameligoExampleSmall = `${pre}ocaml
 type storage = int
 

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

@@ -210,9 +210,9 @@ and type_tuple = (type_expr, comma) nsepseq par reg
 
 (* Function and procedure declarations *)
 
-and fun_decl = {
+and fun_expr = {
   kwd_function : kwd_function;
-  name         : variable;
+  name         : variable option;
   param        : parameters;
   colon        : colon;
   ret_type     : type_expr;
@@ -221,7 +221,11 @@ and fun_decl = {
   block        : block reg option;
   kwd_with     : kwd_with option;
   return       : expr;
-  terminator   : semi option
+}
+
+and fun_decl = {
+  fun_expr : fun_expr reg ;
+  terminator : semi option ;
 }
 
 and parameters = (param_decl, semi) nsepseq par reg
@@ -266,12 +270,12 @@ and statement =
 | Data  of data_decl
 
 and local_decl =
-  LocalFun  of fun_decl reg
 | LocalData of data_decl
 
 and data_decl =
   LocalConst of const_decl reg
 | LocalVar   of var_decl reg
+| LocalFun  of fun_decl reg
 
 and var_decl = {
   kwd_var    : kwd_var;
@@ -464,6 +468,7 @@ and expr =
 | EUnit   of c_Unit
 | ETuple  of tuple_expr
 | EPar    of expr par reg
+| EFun    of fun_expr reg
 
 and annot_expr = (expr * type_expr)
 
@@ -644,7 +649,8 @@ let rec expr_to_region = function
 | EUnit   region
 | ECase  {region;_}
 | ECond  {region; _}
-| EPar   {region; _} -> region
+| EPar   {region; _}
+| EFun   {region; _} -> region
 
 and tuple_expr_to_region {region; _} = region
 
@@ -752,7 +758,7 @@ let pattern_to_region = function
 | PTuple      {region; _} -> region
 
 let local_decl_to_region = function
-  LocalFun             {region; _}
+| LocalData LocalFun   {region; _}
 | LocalData LocalConst {region; _}
 | LocalData LocalVar   {region; _} -> region
 

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

@@ -201,9 +201,9 @@ and type_tuple = (type_expr, comma) nsepseq par reg
 
 (* Function declarations *)
 
-and fun_decl ={
+and fun_expr = {
   kwd_function : kwd_function;
-    name         : variable;
+  name         : variable option;
   param        : parameters;
   colon        : colon;
   ret_type     : type_expr;
@@ -212,7 +212,12 @@ and fun_decl ={
   block        : block reg option;
   kwd_with     : kwd_with option;
   return       : expr;
-    terminator   : semi option }
+}
+
+and fun_decl = {
+  fun_expr : fun_expr reg ;
+  terminator : semi option ;
+}
 
 and parameters = (param_decl, semi) nsepseq par reg
 
@@ -256,12 +261,12 @@ and statement =
 | Data  of data_decl
 
 and local_decl =
-  LocalFun  of fun_decl reg
 | LocalData of data_decl
 
 and data_decl =
   LocalConst of const_decl reg
 | LocalVar   of var_decl reg
+| LocalFun  of fun_decl reg
 
 and var_decl = {
   kwd_var    : kwd_var;
@@ -454,6 +459,7 @@ and expr =
 | EUnit   of c_Unit
 | ETuple  of tuple_expr
 | EPar    of expr par reg
+| EFun    of fun_expr reg
 
 and annot_expr = (expr * type_expr)
 

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

@@ -239,17 +239,11 @@ field_decl:
     and value  = {field_name = $1; colon = $2; field_type = $3}
     in {region; value} }
 
-(* Function declarations *)
-
-fun_decl:
-  Function fun_name parameters COLON type_expr Is
-    seq(local_decl)
+fun_expr:
+  Function option(fun_name) parameters COLON type_expr Is
     block
-  With expr option(SEMI) {
-    let stop =
-      match $11 with
-        Some region -> region
-      |        None -> expr_to_region $10 in
+  With expr {
+    let stop = expr_to_region $9 in
     let region = cover $1 stop
     and value = {
       kwd_function = $1;
@@ -258,18 +252,15 @@ fun_decl:
       colon        = $4;
       ret_type     = $5;
       kwd_is       = $6;
-      local_decls  = $7;
-      block        = Some $8;
-      kwd_with     = Some $9;
-      return       = $10;
-      terminator   = $11}
+      local_decls  = [];
+      block        = Some $7;
+      kwd_with     = Some $8;
+      return       = $9;
+      }
     in {region;value}}
-  | Function fun_name parameters COLON type_expr Is
-      expr option(SEMI) {
-        let stop =
-          match $8 with
-            Some region -> region
-          | None -> expr_to_region $7 in
+  | Function option(fun_name) parameters COLON type_expr Is
+      expr {
+        let stop = expr_to_region $7 in
         let region = cover $1 stop
         and value = {
             kwd_function = $1;
@@ -282,10 +273,36 @@ fun_decl:
             block        = None;
             kwd_with     = None;
             return       = $7;
-            terminator   = $8;
           }
         in {region;value}}
 
+
+
+(* Function declarations *)
+
+fun_decl:
+  fun_expr option(SEMI) {
+    let stop =
+      match $2 with
+        Some region -> region
+      |        None -> $1.region in
+    let region = cover $1.region stop
+    and value = {
+      fun_expr = $1;
+      terminator = $2;
+      }
+    in {region;value}}
+
+open_fun_decl:
+  fun_expr {
+    let region = $1.region
+    and value = {
+      fun_expr = $1;
+      terminator = None;
+      }
+    in {region;value}}
+
+
 parameters:
   par(nsepseq(param_decl,SEMI)) { $1 }
 
@@ -341,6 +358,7 @@ statement:
 open_data_decl:
   open_const_decl { LocalConst $1 }
 | open_var_decl   { LocalVar   $1 }
+| open_fun_decl   { LocalFun   $1 }
 
 open_const_decl:
   Const unqualified_decl(EQ) {
@@ -370,14 +388,6 @@ open_var_decl:
       terminator = None}
     in {region; value}}
 
-local_decl:
-  fun_decl  { LocalFun  $1 }
-| data_decl { LocalData $1 }
-
-data_decl:
-  const_decl { LocalConst $1 }
-| var_decl   { LocalVar   $1 }
-
 unqualified_decl(OP):
   var COLON type_expr OP expr {
     let region = expr_to_region $5
@@ -390,12 +400,6 @@ const_decl:
   }
 | open_const_decl { $1 }
 
-var_decl:
-  open_var_decl SEMI {
-    let var_decl : AST.var_decl = $1.value in
-    {$1 with value = {var_decl with terminator = Some $2}}
-  }
-| open_var_decl { $1 }
 
 instruction:
   conditional  {        Cond $1 }
@@ -683,6 +687,7 @@ expr:
   case(expr) { ECase ($1 expr_to_region) }
 | cond_expr  { $1                        }
 | disj_expr  { $1                        }
+| fun_expr   { EFun $1                   }
 
 cond_expr:
   If expr Then expr option(SEMI) Else expr {

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

@@ -156,12 +156,13 @@ and print_type_tuple buffer {value; _} =
   print_nsepseq buffer "," print_type_expr inside;
   print_token buffer rpar ")"
 
-and print_fun_decl buffer {value; _} =
+and print_fun_expr buffer {value; _} =
   let {kwd_function; name; param; colon;
        ret_type; kwd_is; local_decls;
-       block; kwd_with; return; terminator} = value in
+       block; kwd_with; return;} = value in
+  let anonymous_name = Region.wrap_ghost "#anonymous" in
   print_token       buffer kwd_function "function";
-  print_var         buffer name;
+  print_var         buffer @@ Simple_utils.Option.unopt ~default:anonymous_name name;
   print_parameters  buffer param;
   print_token       buffer colon ":";
   print_type_expr   buffer ret_type;
@@ -173,7 +174,11 @@ and print_fun_decl buffer {value; _} =
     print_token       buffer kwd_with "with";
   | None          ->  ();
   print_expr        buffer return;
-  print_terminator  buffer terminator
+
+and print_fun_decl buffer {value; _} =
+  let {fun_expr ; terminator;} = value in
+  print_fun_expr buffer fun_expr;
+  print_terminator buffer terminator;
 
 and print_parameters buffer {value; _} =
   let {lpar; inside; rpar} = value in
@@ -225,12 +230,12 @@ and print_local_decls buffer sequence =
   List.iter (print_local_decl buffer) sequence
 
 and print_local_decl buffer = function
-  LocalFun  decl -> print_fun_decl  buffer decl
 | LocalData decl -> print_data_decl buffer decl
 
 and print_data_decl buffer = function
   LocalConst decl -> print_const_decl buffer decl
 | LocalVar   decl -> print_var_decl   buffer decl
+| LocalFun  decl -> print_fun_decl  buffer decl
 
 and print_var_decl buffer {value; _} =
   let {kwd_var; name; colon; var_type;
@@ -402,6 +407,7 @@ and print_expr buffer = function
 | EUnit   r -> print_token buffer r "Unit"
 | ETuple  e -> print_tuple_expr buffer e
 | EPar    e -> print_par_expr buffer e
+| EFun    e -> print_fun_expr buffer e
 
 and print_annot_expr buffer (expr , type_expr) =
   print_expr buffer expr;
@@ -795,7 +801,7 @@ and pp_declaration buffer ~pad:(_,pc as pad) = function
     pp_const_decl buffer ~pad value
 | FunDecl {value; region} ->
     pp_loc_node buffer ~pad "FunDecl" region;
-    pp_fun_decl buffer ~pad value
+    pp_fun_expr buffer ~pad value.fun_expr.value
 
 and pp_const_decl buffer ~pad:(_,pc) decl =
   pp_ident buffer ~pad:(mk_pad 3 0 pc) decl.name;
@@ -861,12 +867,13 @@ and pp_type_tuple buffer ~pad:(_,pc) {value; _} =
     pp_type_expr buffer ~pad:(mk_pad len rank pc)
   in List.iteri (List.length components |> apply) components
 
-and pp_fun_decl buffer ~pad:(_,pc) decl =
+and pp_fun_expr buffer ~pad:(_,pc) decl =
   let fields =
     if decl.local_decls = [] then 5 else 6 in
   let () =
     let pad = mk_pad fields 0 pc in
-    pp_ident buffer ~pad decl.name in
+    let anonymous_name = Region.wrap_ghost "#anonymous" in
+    pp_ident buffer ~pad @@ Simple_utils.Option.unopt ~default:anonymous_name decl.name in
   let () =
     let pad = mk_pad fields 1 pc in
     pp_node buffer ~pad "<parameters>";
@@ -1294,9 +1301,6 @@ and pp_local_decls buffer ~pad:(_,pc) decls =
   in List.iteri (List.length decls |> apply) decls
 
 and pp_local_decl buffer ~pad:(_,pc as pad) = function
-  LocalFun {value; region} ->
-    pp_loc_node buffer ~pad "LocalFun" region;
-    pp_fun_decl buffer ~pad value
 | LocalData data ->
     pp_node buffer ~pad "LocalData";
     pp_data_decl buffer ~pad:(mk_pad 1 0 pc) data
@@ -1308,6 +1312,9 @@ and pp_data_decl buffer ~pad = function
 | LocalVar {value; region} ->
     pp_loc_node buffer ~pad "LocalVar" region;
     pp_var_decl buffer ~pad value
+| LocalFun {value; region} ->
+    pp_loc_node buffer ~pad "LocalFun" region;
+    pp_fun_expr buffer ~pad value.fun_expr.value
 
 and pp_var_decl buffer ~pad:(_,pc) decl =
   pp_ident     buffer ~pad:(mk_pad 3 0 pc) decl.name;
@@ -1368,6 +1375,9 @@ and pp_expr buffer ~pad:(_,pc as pad) = function
 | EPar {value; region} ->
     pp_loc_node buffer ~pad "EPar" region;
     pp_expr buffer ~pad:(mk_pad 1 0 pc) value.inside
+| EFun {value; region} ->
+    pp_loc_node buffer ~pad "EFun" region;
+    pp_fun_expr ~pad buffer value;
 
 and pp_list_expr buffer ~pad:(_,pc as pad) = function
   ECons {value; region} ->

src/passes/2-simplify/pascaligo.ml

@@ -117,6 +117,22 @@ module Errors = struct
     ] in
     error ~data title message
 
+  let unexpected_anonymous_function loc =
+    let title () = "unexpected anonymous function" in
+    let message () = "you provided a function declaration without name" in
+    let data = [
+        ("loc" , fun () -> Format.asprintf "%a" Location.pp @@ loc)
+      ] in
+    error ~data title message
+
+  let unexpected_named_function loc =
+    let title () = "unexpected named function" in
+    let message () = "you provided a function expression with a name (remove it)" in
+    let data = [
+        ("loc" , fun () -> Format.asprintf "%a" Location.pp @@ loc)
+      ] in
+    error ~data title message
+
   (* Logging *)
 
   let simplifying_instruction t =
@@ -410,6 +426,13 @@ let rec simpl_expression (t:Raw.expr) : expr result =
       let%bind index = simpl_expression lu.index.value.inside in
       return @@ e_look_up ~loc path index
     )
+  | EFun f -> (
+    let (f , loc) = r_split f in
+    let%bind ((name_opt , _ty_opt) , f') = simpl_fun_expression ~loc f in
+    match name_opt with
+    | None -> return @@ f'
+    | Some _ -> fail @@ unexpected_named_function loc
+  )
 
 and simpl_logic_expression (t:Raw.logic_expr) : expression result =
   let return x = ok x in
@@ -497,10 +520,6 @@ and simpl_local_declaration : Raw.local_decl -> _ result = fun t ->
   match t with
   | LocalData d ->
       simpl_data_declaration d
-  | LocalFun f  ->
-      let (f , loc) = r_split f in
-      let%bind (name , e) = simpl_fun_declaration ~loc f in
-      return_let_in ~loc name e
 
 and simpl_data_declaration : Raw.data_decl -> _ result = fun t ->
   match t with
@@ -516,6 +535,11 @@ and simpl_data_declaration : Raw.data_decl -> _ result = fun t ->
       let%bind t = simpl_type_expression x.const_type in
       let%bind expression = simpl_expression x.init in
       return_let_in ~loc (name , Some t) expression
+  | LocalFun f  ->
+      let (f , loc) = r_split f in
+      let%bind ((name_opt , ty_opt) , e) = simpl_fun_expression ~loc f.fun_expr.value in
+      let%bind name = trace_option (unexpected_anonymous_function loc) name_opt in
+      return_let_in ~loc (name , ty_opt) e
 
 and simpl_param : Raw.param_decl -> (type_name * type_expression) result =
   fun t ->
@@ -531,11 +555,11 @@ and simpl_param : Raw.param_decl -> (type_name * type_expression) result =
       let%bind type_expression = simpl_type_expression c.param_type in
       ok (type_name , type_expression)
 
-and simpl_fun_declaration :
-  loc:_ -> Raw.fun_decl -> ((name * type_expression option) * expression) result =
+and simpl_fun_expression :
+  loc:_ -> Raw.fun_expr -> ((name option * type_expression option) * expression) result =
   fun ~loc x ->
   let open! Raw in
-  let {name;param;ret_type;local_decls;block;return} : fun_decl = x in
+  let {name;param;ret_type;local_decls;block;return} : fun_expr = x in
   let statements =
     match block with
     | Some block -> npseq_to_list block.value.statements
@@ -544,7 +568,7 @@ and simpl_fun_declaration :
   (match param.value.inside with
      a, [] -> (
        let%bind input = simpl_param a in
-       let name = name.value in
+       let name = Option.map (fun (x : _ reg) -> x.value) name in
        let (binder , input_type) = input in
        let%bind local_declarations =
          bind_map_list simpl_local_declaration local_decls in
@@ -591,7 +615,8 @@ and simpl_fun_declaration :
        let expression =
          e_lambda ~loc binder (Some input_type) (Some output_type) result in
        let type_annotation = Some (T_function (input_type, output_type)) in
-       ok ((name.value , type_annotation) , expression)
+       let name = Option.map (fun (x : _ reg) -> x.value) name in
+       ok ((name , type_annotation) , expression)
      )
   )
 and simpl_declaration : Raw.declaration -> declaration Location.wrap result =
@@ -614,7 +639,8 @@ and simpl_declaration : Raw.declaration -> declaration Location.wrap result =
       bind_map_location simpl_const_decl (Location.lift_region x)
   | FunDecl x -> (
       let (x , loc) = r_split x in
-      let%bind ((name , ty_opt) , expr) = simpl_fun_declaration ~loc x in
+      let%bind ((name_opt , ty_opt) , expr) = simpl_fun_expression ~loc x.fun_expr.value in
+      let%bind name = trace_option (unexpected_anonymous_function loc) name_opt in
       ok @@ Location.wrap ~loc (Declaration_constant (name , ty_opt , expr))
     )
 

src/test/contracts/big_map.ligo

@@ -2,8 +2,8 @@ type storage_ is big_map(int, int) * unit
 type foo is big_map(int, int)
 
 function main(const p : unit; const s : storage_) : list(operation) * storage_ is
-  var toto : option (int) := Some(0);
   block {
+    var toto : option (int) := Some(0);
     toto := s.0[23];
     s.0[2] := 444;
   }

src/test/contracts/closure-1.ligo

@@ -1,4 +1,5 @@
 function foo (const i : int) : int is
+  block {
     function bar (const j : int) : int is
-    block { skip } with i + j ;
-  block { skip } with bar (i)
+      i + j ;
+  } with bar (i)

src/test/contracts/closure-2.ligo

@@ -1,5 +1,6 @@
 function foobar(const i : int) : int is
+  block {
     const j : int = 3 ;
     function toto(const k : int) : int is
-    block { skip } with i + j + k ;
-  block { skip } with toto(42)
+      i + j + k ;
+  } with toto(42)

src/test/contracts/closure-3.ligo

@@ -3,8 +3,10 @@
 // https://gitlab.com/ligolang/ligo/commit/faf3bbc06106de98189f1c1673bd57e78351dc7e
 
 function foobar(const i : int) : int is
+  block {
     const j : int = 3 ;
     const k : int = 4 ;
     function toto(const l : int) : int is
-    block { skip } with i + j + k + l;
-  block { skip } with toto(42)
+      i + j + k + l;
+
+  } with toto(42)

src/test/contracts/closure.ligo

@@ -1,6 +1,7 @@
 function toto (const i : int) : int is
+  block {
     function tata (const j : int) : int is
-    block { skip } with i + j ;
+      i + j ;
     function titi (const j : int) : int is
-    block { skip } with i + j ;
-  block { skip } with tata(i) + titi(i)
+      i + j ;
+  } with tata(i) + titi(i)

src/test/contracts/condition.ligo

@@ -1,8 +1,8 @@
 // Test if conditional in PascaLIGO
 
 function main (const i : int) : int is
-  var result : int := 23 ;
   begin
+    var result : int := 23 ;
     if i = 2 then
       result := 42
     else
@@ -10,7 +10,7 @@ function main (const i : int) : int is
   end with result
 
 function foo (const b : bool) : int is
-  var x : int := 41 ;
   begin
+    var x : int := 41 ;
     x := 1 + (if b then x else main(x)) ;
   end with x

src/test/contracts/deep_access.ligo

@@ -3,20 +3,17 @@ type pii is (int*int)
 type ppi is record x:pii; y:pii end
 type ppp is (ppi*ppi)
 
-function main (const toto : unit) : int is
-var a : ppp := 
-(
+function main (const toto : unit) : int is block {
+  var a : ppp := (
     record
       x = (0,1);
       y = (10,11);
-end
-,
+    end ,
     record
       x = (100,101);
       y = (110,111);
     end
-)
-begin 
+  ) ;
   a.0.x.0 := 2;
   const b:int = a.0.x.0;
-end with b
+} with b

src/test/contracts/failwith.ligo

@@ -12,8 +12,8 @@ function main (const p : param; const s : unit) : list(operation) * unit is
   with ((nil : list(operation)), s)
 
 function foobar (const i : int) : int is
-  var p : param := Zero (42n) ;
   block {
+    var p : param := Zero (42n) ;
     if i > 0 then block {
       i := i + 1 ;
       if i > 10 then block {

src/test/contracts/function-anon.ligo

@@ -0,0 +1 @@
+const x : int = (function (const i : int) : int is i + 1)(41)

src/test/contracts/function-complex.ligo

@@ -1,9 +1,9 @@
 // Test a PascaLIGO function with more complex logic than function.ligo
 
 function main (const i : int) : int is
+  begin
     var j : int := 0 ;
     var k : int := 1 ;
-  begin
     j := k + i ;
     k := i + j ;
   end with (k + j)

src/test/contracts/high-order.ligo

@@ -1,10 +1,11 @@
 // Test a PascaLIGO function which takes another PascaLIGO function as an argument
 function foobar (const i : int) : int is
+  block {
     function foo (const i : int) : int is
-    block { skip } with i ;
+      i ;
     function bar (const f : int -> int) : int is
-    block { skip } with f ( i ) ;
-  block { skip } with bar (foo) ;
+      f ( i ) ;
+ } with bar (foo) ;
 
 // higher order function with more than one argument
 function higher2(const i: int; const f: int -> int): int is
@@ -13,27 +14,26 @@ function higher2(const i: int; const f: int -> int): int is
    } with ii
 
 function foobar2 (const i : int) : int is
+  block {
     function foo2 (const i : int) : int is
-    block { skip } with i;
-  block { skip } with higher2(i,foo2)
+      i;
+  } with higher2(i,foo2)
 
 const a : int = 0;
 function foobar3 (const i : int) : int is
+  block {
     function foo2 (const i : int) : int is
-    block { skip } with (a+i);
-  block { skip } with higher2(i,foo2)
+      (a+i);
+  } with higher2(i,foo2)
 
 function f (const i : int) : int is
-  block { skip }
-  with i
+  i
 
 function g (const i : int) : int is
-  block { skip }
-  with f(i)
+  f(i)
 
 function foobar4 (const i : int) : int is
-  block { skip }
-  with g(g(i))
+  g(g(i))
 
 function higher3(const i: int; const f: int -> int; const g: int -> int): int is
   block {
@@ -41,9 +41,10 @@ function higher3(const i: int; const f: int -> int; const g: int -> int): int is
    } with ii
 
 function foobar5 (const i : int) : int is
+  block {
     const a : int = 0;
     function foo (const i : int) : int is
-    block { skip } with (a+i);
+      (a+i);
     function goo (const i : int) : int is
-    block { skip } with foo(i);
-  block { skip } with higher3(i,foo,goo)
+      foo(i);
+  } with higher3(i,foo,goo)

src/test/contracts/lambda.ligo

@@ -2,5 +2,6 @@ function f (const x : unit) : unit is
   begin skip end with unit
 
 function main (const p : unit ; const s : unit) : unit is
+  begin
     var y : unit := f(unit) ;
-  begin skip end with y
+  end with y

src/test/contracts/list.ligo

@@ -25,15 +25,16 @@ const bl : foobar = list
 end
 
 function iter_op (const s : list(int)) : int is
+  begin
     var r : int := 0 ;
     function aggregate (const i : int) : unit is
       begin
         r := r + i ;
-  end with unit
-  begin
+      end with unit ;
     list_iter(s , aggregate) ;
   end with r
 
 function map_op (const s : list(int)) : list(int) is
+  block {
     function increment (const i : int) : int is block { skip } with i + 1
-  block { skip } with list_map(s , increment)
+  } with list_map(s , increment)

src/test/contracts/map.ligo

@@ -48,23 +48,25 @@ function get_ (const m : foobar) : option(int) is
   end with map_get(42 , m)
 
 function iter_op (const m : foobar) : unit is
+  block {
     function aggregate (const i : int ; const j : int) : unit is block
       { if (i=j) then skip else failwith("fail") } with unit ;
-  block {skip}
     // map_iter(m , aggregate) ;
-  with map_iter(m, aggregate) ;
+  } with map_iter(m, aggregate) ;
 
 function map_op (const m : foobar) : foobar is
+  block {
     function increment (const i : int ; const j : int) : int is block { skip } with j + 1 ;
-  block { skip } with map_map(m , increment) ;
+  } with map_map(m , increment) ;
 
 function fold_op (const m : foobar) : int is
+  block {
     function aggregate (const i : int ; const j : (int * int)) : int is block { skip } with i + j.0 + j.1 ;
-  block { skip } with map_fold(m , 10 , aggregate)
+  } with map_fold(m , 10 , aggregate)
 
 function deep_op (var m : foobar) : foobar is
-var coco : (int*foobar) := (0, m);
   block {
+    var coco : (int*foobar) := (0, m);
     remove 42 from map coco.1 ;
     coco.1[32] := 16 ;
   } with coco.1

src/test/contracts/match.ligo

@@ -1,8 +1,8 @@
 // Test the pattern matching functionality of PascaLIGO
 
 function match_bool (const i : int) : int is
-  var result : int := 23 ;
   begin
+    var result : int := 23 ;
     case i = 2 of
     | True -> result := 42
     | False -> result := 0
@@ -10,8 +10,8 @@ function match_bool (const i : int) : int is
   end with result
 
 function match_option (const o : option(int)) : int is
-  var result : int := 23 ;
   begin
+    var result : int := 23 ;
     case o of
     | None -> skip
     | Some (s) -> result := s
@@ -19,21 +19,18 @@ function match_option (const o : option(int)) : int is
   end with result
 
 function match_expr_bool (const i : int) : int is
-  begin skip end with
   case i = 2 of
   | True -> 42
   | False -> 0
   end
 
 function match_expr_option (const o : option(int)) : int is
-  begin skip end with
   case o of
   | None -> 42
   | Some (s) -> s
   end
 
 function match_expr_list (const l : list(int)) : int is
-  begin skip end with
   case l of
   | nil -> -1
   | hd # tl -> hd

src/test/contracts/option.ligo

@@ -6,10 +6,8 @@ const s : foobar = Some(42)
 const n : foobar = None
 
 function assign (var m : int) : foobar is
+  block {
     var coco : foobar := None;
-  block
-{
     coco := Some(m);
     coco := None;
-}
-with coco
+  } with coco

src/test/contracts/set_arithmetic-1.ligo

@@ -1,16 +1,17 @@
 // Test set iteration in PascaLIGO
 
 function iter_op (const s : set(int)) : int is
+  begin
     var r : int := 0 ;
     function aggregate (const i : int) : unit is
       begin
         r := r + i ;
-  end with unit
-  begin
+      end with unit ;
     set_iter(s , aggregate) ;
   end with r
 
 function fold_op (const s : set(int)) : int is
+  block {
     function aggregate (const i : int ; const j : int) : int is
-  block { skip } with i + j
-  block { skip } with set_fold(s , 15 , aggregate)
+      i + j
+  } with set_fold(s , 15 , aggregate)

src/test/contracts/shadow.ligo

@@ -1,4 +1,5 @@
 function foo (const i : int) : int is
+  block {
     function bar (const i : int) : int is
-    block { skip } with i ;
-  block { skip } with bar (0)
+      i ;
+  } with bar (0)

src/test/contracts/simple_access.ligo

@@ -7,10 +7,10 @@ end
 type mpi is map(string,int)
 
 function main (const toto : tpi) : int is
+  begin
     var a : tpi := toto;
     var b : rpi := record x = 0; y=1 ; end;
     var m : mpi := map "y" -> 1; end;
-	begin 
     a.0 := 2;
     b.x := a.0;
     m["x"] := b.x;

src/test/contracts/website2.ligo

@@ -3,15 +3,13 @@ type action is
 | Increment of int
 | Decrement of int
 
-function add (const a : int ; const b : int) : int is
-    block { skip } with a + b
+function add (const a : int ; const b : int) : int is a + b
 
-function subtract (const a : int ; const b : int) : int is
-    block { skip } with a - b
+function subtract (const a : int ; const b : int) : int is a - b
 
 // real entrypoint that re-routes the flow based on the action provided
 function main (const p : action ; const s : int) : (list(operation) * int) is 
-  block {skip} with ((nil : list(operation)),
+  ((nil : list(operation)),
     case p of
     | Increment (n) -> add (s, n)
     | Decrement (n) -> subtract (s, n)

src/test/integration_tests.ml

@@ -52,6 +52,13 @@ let complex_function () : unit result =
   let make_expect = fun n -> (3 * n + 2) in
   expect_eq_n_int program "main" make_expect
 
+let anon_function () : unit result =
+  let%bind program = type_file "./contracts/function-anon.ligo" in
+  let%bind () =
+    expect_eq_evaluate program "x" (e_int 42)
+  in
+  ok ()
+
 let application () : unit result =
   let%bind program = type_file "./contracts/application.ligo" in
   let%bind () =
@@ -1196,6 +1203,7 @@ let main = test_suite "Integration (End to End)" [
     test "assign" assign ;
     test "declaration local" declaration_local ;
     test "complex function" complex_function ;
+    test "anon function" anon_function ;
     test "various applications" application ;
     test "closure" closure ;
     test "shared function" shared_function ;

vendors/ligo-utils/simple-utils/region.ml

@@ -108,6 +108,8 @@ let make ~(start: Pos.t) ~(stop: Pos.t) =
 
 let ghost = make ~start:Pos.ghost ~stop:Pos.ghost
 
+let wrap_ghost value = {value ; region = ghost}
+
 let min = make ~start:Pos.min ~stop:Pos.min
 
 (* Comparisons *)

vendors/ligo-utils/simple-utils/region.mli

@@ -96,6 +96,11 @@ val make : start:Pos.t -> stop:Pos.t -> t
 
 val ghost : t (* Two [Pos.ghost] positions *)
 
+(* This wraps a value with a ghost region. *)
+
+val wrap_ghost : 'a -> 'a reg
+
+
 (* Occasionnally, we may need a minimum region. It is here made of two
    minimal positions. *)