Merge branch 'ast/tuple_destruct' into 'dev'

Add a sugar operation : Tuple Destructuring

See merge request ligolang/ligo!650

src/passes/3-self_ast_imperative/helpers.ml

@@ -82,6 +82,11 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
      let%bind res = self init' tuple in
      ok res
     )
+  | E_tuple_destruct {tuple; next} -> (
+    let%bind res = self init' tuple in
+    let%bind res = self res next in
+    ok res
+  )
   | E_let_in { let_binder = _ ; rhs ; let_result } -> (
       let%bind res = self init' rhs in
       let%bind res = self res let_result in
@@ -205,6 +210,11 @@ let rec map_expression : exp_mapper -> expression -> expression result = fun f e
      let%bind tuple = self tuple in
      return @@ E_tuple_accessor {tuple;path}
     )
+  | E_tuple_destruct {tuple;fields;field_types;next} -> (
+     let%bind tuple = self tuple in
+     let%bind next  = self next in
+     return @@ E_tuple_destruct {tuple;fields;field_types;next}
+    )
   | E_constructor c -> (
       let%bind e' = self c.element in
       return @@ E_constructor {c with element = e'}
@@ -384,6 +394,11 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
      let%bind (res, tuple) = self init' tuple in
      ok (res, return @@ E_tuple_accessor {tuple; path})
     )
+  | E_tuple_destruct {tuple;fields;field_types;next} -> (
+     let%bind (res,tuple) = self init' tuple in
+     let%bind (res,next)  = self res next in
+     ok (res, return @@ E_tuple_destruct {tuple;fields;field_types;next})
+     )
   | E_constructor c -> (
       let%bind (res,e') = self init' c.element in
       ok (res, return @@ E_constructor {c with element = e'})

src/passes/4-imperative_to_sugar/imperative_to_sugar.ml

@@ -57,9 +57,10 @@ let repair_mutable_variable_in_matching (match_body : O.expression) (element_nam
       | E_constant _
       | E_skip
       | E_literal _ | E_variable _
-      | E_application _ | E_lambda _| E_recursive _
+      | E_application _ | E_lambda _| E_recursive _ | E_constructor _ 
-      | E_constructor _ | E_record _| E_record_accessor _|E_record_update _
+      | E_record _| E_record_accessor _|E_record_update _ | E_ascription _  
-      | E_ascription _  | E_sequence _ | E_tuple _ | E_tuple_accessor _ | E_tuple_update _
+      | E_sequence _ | E_tuple _ | E_tuple_accessor _ | E_tuple_update _
+      | E_tuple_destruct _
       | E_map _ | E_big_map _ |E_list _ | E_set _ |E_look_up _
        -> ok (true, (decl_var, free_var),ass_exp)
     )
@@ -104,6 +105,7 @@ and repair_mutable_variable_in_loops (for_body : O.expression) (element_names :
       | E_application _ | E_lambda _| E_recursive _
       | E_constructor _ | E_record _| E_record_accessor _|E_record_update _
       | E_ascription _  | E_sequence _ | E_tuple _ | E_tuple_accessor _ | E_tuple_update _
+      | E_tuple_destruct _
       | E_map _ | E_big_map _ |E_list _ | E_set _ |E_look_up _
        -> ok (true, (decl_var, free_var),ass_exp)
     )
@@ -335,6 +337,11 @@ and compile_expression' : I.expression -> (O.expression option -> O.expression)
       let%bind tuple = compile_expression tuple in
       let%bind update = compile_expression update in
       return @@ O.e_tuple_update ~loc tuple path update
+    | I.E_tuple_destruct {tuple; fields; field_types; next} ->
+      let%bind tuple = compile_expression tuple in
+      let%bind next  = compile_expression next in
+      let%bind field_types = bind_map_option (bind_map_list compile_type_expression) field_types in
+      return @@ O.e_tuple_destruct ~loc tuple fields field_types next
     | I.E_assign {variable; access_path; expression} ->
       let accessor ?loc s a =
         match a with 
@@ -724,6 +731,11 @@ let rec uncompile_expression' : O.expression -> I.expression result =
     let%bind tuple  = uncompile_expression' tuple in
     let%bind update = uncompile_expression' update in
     return @@ I.E_tuple_update {tuple;path;update}
+  | O.E_tuple_destruct {tuple; fields; field_types; next} ->
+    let%bind tuple = uncompile_expression' tuple in
+    let%bind next  = uncompile_expression' next in
+    let%bind field_types = bind_map_option (bind_map_list uncompile_type_expression) field_types in
+    return @@ I.E_tuple_destruct {tuple; fields; field_types; next}
   | O.E_map map ->
     let%bind map = bind_map_list (
       bind_map_pair uncompile_expression'

src/passes/5-self_ast_sugar/helpers.ml

@@ -99,6 +99,11 @@ let rec fold_expression : 'a folder -> 'a -> expression -> 'a result = fun f ini
      let%bind res = self init' tuple in
      ok res
     )
+  | E_tuple_destruct {tuple; next} -> (
+    let%bind res = self init' tuple in
+    let%bind res = self res next in
+    ok res
+  )
      
 
 and fold_cases : 'a folder -> 'a -> matching_expr -> 'a result = fun f init m ->
@@ -225,6 +230,11 @@ let rec map_expression : exp_mapper -> expression -> expression result = fun f e
      let%bind tuple = self tuple in
      return @@ E_tuple_accessor {tuple;path}
     )
+  | E_tuple_destruct {tuple;fields;field_types;next} -> (
+     let%bind tuple = self tuple in
+     let%bind next  = self next in
+     return @@ E_tuple_destruct {tuple;fields;field_types;next}
+    )
   | E_literal _ | E_variable _ | E_skip as e' -> return e'
 
 and map_type_expression : ty_exp_mapper -> type_expression -> type_expression result = fun f te ->
@@ -353,6 +363,11 @@ let rec fold_map_expression : 'a fold_mapper -> 'a -> expression -> ('a * expres
      let%bind (res, tuple) = self init' tuple in
      ok (res, return @@ E_tuple_accessor {tuple; path})
     )
+  | E_tuple_destruct {tuple;fields;field_types;next} -> (
+     let%bind (res,tuple) = self init' tuple in
+     let%bind (res,next)  = self res next in
+     ok (res, return @@ E_tuple_destruct {tuple;fields;field_types;next})
+     )
   | E_constructor c -> (
       let%bind (res,e') = self init' c.element in
       ok (res, return @@ E_constructor {c with element = e'})

src/passes/6-sugar_to_core/sugar_to_core.ml

@@ -193,6 +193,23 @@ let rec compile_expression : I.expression -> O.expression result =
       let path        = O.Label (string_of_int path) in
       let%bind update = compile_expression update in
       return @@ O.E_record_update {record;path;update}
+    | I.E_tuple_destruct {tuple; fields; field_types; next} ->
+      let combine fields field_types =
+        match field_types with
+          Some ft -> List.combine fields @@ List.map (fun x -> Some x) ft
+        | None    -> List.map (fun x -> (x, None)) fields
+      in
+      let%bind record = compile_expression tuple in
+      let%bind next   = compile_expression next in
+      let%bind field_types = bind_map_option (bind_map_list idle_type_expression) field_types in
+      let aux ((index,e) : int * _ ) (field: O.expression_variable * O.type_expression option) =
+        let f = fun expr -> O.e_let_in field false (O.e_record_accessor record (string_of_int index)) expr in
+        (index+1, fun expr -> e (f expr))
+      in
+      let (_,header) = List.fold_left aux (0, fun e -> e) @@
+        combine fields field_types
+      in
+      ok @@ header next
 
 and compile_lambda : I.lambda -> O.lambda result =
   fun {binder;input_type;output_type;result}->

src/stages/1-ast_imperative/PP.ml

@@ -136,6 +136,11 @@ and expression_content ppf (ec : expression_content) =
       fprintf ppf "%a.%d" expression ta.tuple ta.path
   | E_tuple_update {tuple; path; update} ->
       fprintf ppf "{ %a with %d = %a }" expression tuple path expression update
+  | E_tuple_destruct {tuple; fields; next; _} ->
+      fprintf ppf "{ let (%a) = %a in %a"
+        (list_sep_d expression_variable) fields
+        expression tuple
+        expression next
   | E_assign {variable; access_path; expression=e} ->
       fprintf ppf "%a%a := %a" 
         expression_variable variable

src/stages/1-ast_imperative/combinators.ml

@@ -140,6 +140,7 @@ let e_annotation ?loc anno_expr ty = make_e ?loc @@ E_ascription {anno_expr; typ
 let e_tuple ?loc lst : expression = make_e ?loc @@ E_tuple lst
 let e_tuple_accessor ?loc tuple path : expression = make_e ?loc @@ E_tuple_accessor {tuple; path}
 let e_tuple_update ?loc tuple path update : expression = make_e ?loc @@ E_tuple_update {tuple; path; update}
+let e_tuple_destruct ?loc tuple fields field_types next = make_e ?loc @@ E_tuple_destruct {tuple; fields; field_types; next}
 
 let e_pair ?loc a b  : expression = e_tuple ?loc [a;b]
 let e_cond ?loc condition then_clause else_clause = make_e ?loc @@ E_cond {condition;then_clause;else_clause}

src/stages/1-ast_imperative/combinators.mli

@@ -105,6 +105,7 @@ val e_annotation : ?loc:Location.t -> expression -> type_expression -> expressio
 val e_tuple : ?loc:Location.t -> expression list -> expression
 val e_tuple_accessor : ?loc:Location.t -> expression -> int -> expression
 val e_tuple_update : ?loc:Location.t -> expression -> int -> expression -> expression
+val e_tuple_destruct : ?loc:Location.t -> expression -> expression_variable list -> type_expression list option -> expression -> expression
 val e_pair : ?loc:Location.t -> expression -> expression -> expression
 
 val e_cond: ?loc:Location.t -> expression -> expression -> expression -> expression

src/stages/1-ast_imperative/types.ml

@@ -77,6 +77,7 @@ and expression_content =
   | E_tuple of expression list
   | E_tuple_accessor of tuple_accessor
   | E_tuple_update   of tuple_update
+  | E_tuple_destruct of tuple_destruct
   (* Data Structures *)
   | E_map of (expression * expression) list 
   | E_big_map of (expression * expression) list
@@ -144,6 +145,7 @@ and sequence = {
 
 and tuple_accessor = {tuple: expression; path: int}
 and tuple_update   = {tuple: expression; path: int ; update: expression}
+and tuple_destruct = {tuple: expression; fields : expression_variable list; field_types : type_expression list option; next : expression}
 
 and assign = {
   variable : expression_variable;

src/stages/2-ast_sugar/PP.ml

@@ -129,6 +129,11 @@ and expression_content ppf (ec : expression_content) =
       fprintf ppf "%a.%d" expression ta.tuple ta.path
   | E_tuple_update {tuple; path; update} ->
       fprintf ppf "{ %a with %d = %a }" expression tuple path expression update
+  | E_tuple_destruct {tuple; fields; next; _} ->
+      fprintf ppf "{ let (%a) = %a in %a"
+        (list_sep_d expression_variable) fields
+        expression tuple
+        expression next
 
 and option_type_name ppf
     ((n, ty_opt) : expression_variable * type_expression option) =

src/stages/2-ast_sugar/combinators.ml

@@ -129,6 +129,7 @@ let e_annotation ?loc anno_expr ty = make_e ?loc @@ E_ascription {anno_expr; typ
 let e_tuple ?loc lst : expression = make_e ?loc @@ E_tuple lst
 let e_tuple_accessor ?loc tuple path = make_e ?loc @@ E_tuple_accessor {tuple; path}
 let e_tuple_update ?loc tuple path update = make_e ?loc @@ E_tuple_update {tuple; path; update}
+let e_tuple_destruct ?loc tuple fields field_types next = make_e ?loc @@ E_tuple_destruct {tuple; fields; field_types; next}
 let e_pair ?loc a b  : expression = e_tuple ?loc [a;b]
 
 let e_cond ?loc condition then_clause else_clause = make_e ?loc @@ E_cond {condition;then_clause;else_clause}

src/stages/2-ast_sugar/combinators.mli

@@ -85,6 +85,7 @@ val e_annotation : ?loc:Location.t -> expression -> type_expression -> expressio
 val e_tuple : ?loc:Location.t -> expression list -> expression
 val e_tuple_accessor : ?loc:Location.t -> expression -> int -> expression
 val e_tuple_update : ?loc:Location.t -> expression -> int -> expression -> expression
+val e_tuple_destruct : ?loc:Location.t -> expression -> expression_variable list -> type_expression list option -> expression -> expression
 val e_pair : ?loc:Location.t -> expression -> expression -> expression
 
 val e_cond: ?loc:Location.t -> expression -> expression -> expression -> expression

src/stages/2-ast_sugar/types.ml

@@ -77,6 +77,7 @@ and expression_content =
   | E_tuple of expression list
   | E_tuple_accessor of tuple_accessor
   | E_tuple_update   of tuple_update
+  | E_tuple_destruct of tuple_destruct
   (* Data Structures *)
   | E_map of (expression * expression) list 
   | E_big_map of (expression * expression) list
@@ -138,6 +139,7 @@ and sequence = {
 
 and tuple_accessor = {tuple: expression; path: int}
 and tuple_update   = {tuple: expression; path: int ; update: expression}
+and tuple_destruct = {tuple: expression; fields : expression_variable list; field_types : type_expression list option; next : expression}
 
 and environment_element_definition =
   | ED_binder