Support trailing commas in literals

tjammer · Feb 29, 2024 · e954040 · e954040
1 parent b2b692e
commit e954040
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Showing 3 changed files with 33 additions and 29 deletions.
diff --git a/lib/parser.mly b/lib/parser.mly
@@ -141,7 +141,7 @@ func_name:
   | infix = infix_no_inline { $loc(infix), infix }
 
 typedef:
-  | Type; name = decl_typename; Equal; Lbrac; labels = separated_nonempty_list(Comma, record_item_decl); Rbrac
+  | Type; name = decl_typename; Equal; Lbrac; labels = separated_nonempty_trailing_list(Comma, record_item_decl, Rbrac)
     { Trecord ({name; labels = Array.of_list labels}) }
   | Type; name = decl_typename; Equal; spec = type_spec { Talias (name, spec) }
   | Type; name = decl_typename; Equal; ctors = separated_nonempty_list(Hbar, ctor)
@@ -265,22 +265,22 @@ param_pattern:
   | Lpar; tups = tup_tups(param_pattern); Rpar; Ampersand { let loc, tups = tups in Ptup (loc, tups, Dmut) }
   | Lpar; tups = tup_tups(param_pattern); Rpar; Exclamation { let loc, tups = tups in Ptup (loc, tups, Dmove) }
 
-let tup_pattern(x) :=
+tup_pattern(x):
   | tups = tup_tups(x); { let loc, tups = tups in Ptup (loc, tups, Dnorm) }
 
-let tup_tups(x) :=
+tup_tups(x):
   | head = with_loc(x); Comma; tail = separated_nonempty_list(Comma, with_loc(x));
     { $loc, head :: tail }
 
-let record_pattern(x) :=
-  | Lbrac; items = separated_nonempty_list(Comma, record_item_pattern(x)); Rbrac;
+record_pattern(x):
+  | Lbrac; items = separated_nonempty_trailing_list(Comma, record_item_pattern(x), Rbrac);
     { Precord ($loc, items, Dnorm) }
 
-let record_item_pattern(x) :=
+record_item_pattern(x):
   | ident = ident; Equal; pat = x; { ident, Some pat }
   | ident = ident; { ident, None }
 
-let with_loc(x) :=
+with_loc(x):
   | pat = x; { $loc, pat }
 
 ident:
@@ -328,12 +328,12 @@ expr:
     { Lambda ($loc, params, attr, return_annot, body) }
   | Fun; param = only_one_param; attr = loption(capture_copies); Colon; body = block
     { Lambda ($loc, [param], attr, None, body) }
-  | Lbrac; items = separated_nonempty_list(Comma, record_item); Rbrac
+  | Lbrac; items = separated_nonempty_trailing_list(Comma, record_item, Rbrac)
     { Record ($loc, items) }
   | Lpar; tuple = tuple; Rpar { Tuple ($loc, tuple) }
   | Lpar; expr = expr; Rpar { expr }
   | upcases = upcases { upcases }
-  | Lbrac; record = expr; With; items = separated_nonempty_list(Comma, record_item); Rbrac
+  | Lbrac; record = expr; With; items = separated_nonempty_trailing_list(Comma, record_item, Rbrac)
     { Record_update ($loc, record, items) }
   | Do; Colon; block = block { Do_block block }
   | aexpr = expr; Pipe_tail; pipeable = expr
@@ -401,10 +401,18 @@ bool:
   | False { false }
 
 array_lit:
-  | Lbrack; exprs = separated_list(Comma, expr); Rbrack { exprs }
+  | Lbrack; exprs = separated_trailing_list(Comma, expr, Rbrack) { exprs }
+
+separated_nonempty_trailing_list(sep, item, terminator):
+  | x = item; option(sep); terminator { [ x ] }
+  | x = item; sep; xs = separated_nonempty_trailing_list(sep, item, terminator) { x :: xs }
+
+separated_trailing_list(sep, item, terminator):
+  | terminator { [] }
+  | lst = separated_nonempty_trailing_list(sep, item, terminator) { lst }
 
 fixed_array_lit:
-  | Hashtag_brack; items = separated_nonempty_list(Comma, expr); Rbrack { Fixed_array items }
+  | Hashtag_brack; items = separated_nonempty_trailing_list(Comma, expr, Rbrack) { Fixed_array items }
   | num = Hashnum_brack; item = expr; Rbrack { Fixed_array_num (num, item) }
 
 call_arg:
@@ -460,7 +468,7 @@ infix_no_inline:
   | And     { And }
   | Or      { Or }
 
-let parens(x) :=
+parens(x):
   | Lpar; items = separated_list(Comma, x); Rpar; { items }
 
 type_spec:

diff --git a/lib/syntax_errors.messages b/lib/syntax_errors.messages
@@ -582,10 +582,6 @@ prog: Ctor Lpar With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Ctor Lpar Ident Comma Ident Rbrack
-
-<YOUR SYNTAX ERROR MESSAGE HERE>
-
 prog: Ctor Lpar Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
@@ -594,11 +590,11 @@ prog: Lpar Ident Comma With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Hashtag_brack Ident With
+prog: Fmt Lpar Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Hashtag_brack Ident Comma With
+prog: Fmt Lpar Ident Comma With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
@@ -814,15 +810,15 @@ prog: Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Fmt Lpar Ident Rbrack
+prog: Hashnum_brack Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Hashnum_brack Ident With
+prog: Hashtag_brack Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Hashtag_brack Ident Rpar
+prog: Hashtag_brack Ident Comma With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
@@ -890,14 +886,6 @@ prog: Lbrac Ident With With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>
 
-prog: Lbrack Ident Rpar
-
-<YOUR SYNTAX ERROR MESSAGE HERE>
-
-prog: Lpar Ident Comma Ident Rbrack
-
-<YOUR SYNTAX ERROR MESSAGE HERE>
-
 prog: Lpar Ident With
 
 <YOUR SYNTAX ERROR MESSAGE HERE>

diff --git a/test/typing.ml b/test/typing.ml
@@ -116,6 +116,9 @@ let test_record_false () =
   test_exn "Unbound field z on record t"
     "type t = {x : int, y : int}\n{x = 2, z = 2}"
 
+let test_record_trailing () =
+  test "t" "type t = { x : int, y : int }\n{x = 2, y = 2,}"
+
 let test_record_choose () =
   test "t1"
     "type t1 = { x : int, y : int }\n\
@@ -395,6 +398,7 @@ fun get_item(slot):
 get_item|}
 
 let test_array_lit () = test "array(int)" "[0, 1]"
+let test_array_lit_trailing () = test "array(int)" "[0, 1,]"
 
 let test_array_var () = test "array(int)" {|let a = [0, 1]
 a|}
@@ -1219,6 +1223,7 @@ let test_functor_check_concrete () =
      but found (_) -> [make/t('a)]" (check_sig_test "int")
 
 let test_farray_lit () = test "unit" "let arr = #[1, 2, 3]"
+let test_farray_lit_trailing () = test "unit" "let arr = #[1, 2, 3,]"
 
 let test_farray_nested_lit () =
   test "unit" "let arr = #[#[1, 2, 3], #[3, 4, 5]]"
@@ -1281,6 +1286,7 @@ let () =
         [
           case "clear" test_record_clear;
           case "false" test_record_false;
+          case "trailing" test_record_trailing;
           case "choose" test_record_choose;
           case "reorder" test_record_reorder;
           case "create if" test_record_create_if;
@@ -1365,6 +1371,7 @@ let () =
       ( "array",
         [
           case "literal" test_array_lit;
+          case "literal trailing" test_array_lit_trailing;
           case "var" test_array_var;
           case "weak" test_array_weak;
           case "different_types" test_array_different_types;
@@ -1683,6 +1690,7 @@ do:
       ( "fixed-size array",
         [
           case "lit" test_farray_lit;
+          case "lit trailing" test_farray_lit_trailing;
           case "nested lit" test_farray_nested_lit;
           case "generalize / instantiate" test_farray_inference;
         ] );