Remove assert as a reserved keyword

compiler/ml/translcore.ml

@@ -718,6 +718,23 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.lambda =
           [lambda],
           loc )
     | None -> lambda)
+  | Texp_apply
+      {
+        funct =
+          {
+            exp_desc =
+              Texp_ident (_, _, {val_kind = Val_prim {prim_name = "%assert"}});
+          };
+        args = [(_, Some cond)];
+      } -> (
+    (* assert(cond) — same semantics as the old assert keyword *)
+    match cond.exp_desc with
+    | Texp_construct (_, {cstr_name = "false"}, _) ->
+      if !Clflags.no_assert_false then Lambda.lambda_assert_false
+      else assert_failed e
+    | _ ->
+      if !Clflags.noassert then lambda_unit
+      else Lifthenelse (transl_exp cond, lambda_unit, assert_failed e))
   | Texp_apply
       {
         funct =

compiler/ml/typecore.ml

@@ -2503,6 +2503,29 @@ and type_expect_ ?deprecated_context ~context ?in_function ?(recarg = Rejected)
     type_function ?in_function ~arity ~async loc sexp.pexp_attributes env
       ty_expected l
       [Ast_helper.Exp.case spat sbody]
+  | Pexp_apply {funct = {pexp_desc = Pexp_ident lid}; args = [(Nolabel, scond)]}
+    when match Env.lookup_value lid.txt env with
+         | _, {val_kind = Val_prim {Primitive.prim_name = "%assert"}} -> true
+         | _ -> false
+         | exception Not_found -> false ->
+    (* assert(cond) via the %assert primitive — same semantics as the keyword form *)
+    let cond =
+      type_expect ~context:(Some AssertCondition) env scond Predef.type_bool
+    in
+    let exp_type =
+      match cond.exp_desc with
+      | Texp_construct (_, {cstr_name = "false"}, _) -> instance env ty_expected
+      | _ -> instance_def Predef.type_unit
+    in
+    rue
+      {
+        exp_desc = Texp_assert cond;
+        exp_loc = loc;
+        exp_extra = [];
+        exp_type;
+        exp_attributes = sexp.pexp_attributes;
+        exp_env = env;
+      }
   | Pexp_apply {funct = sfunct; args = sargs; partial; transformed_jsx} ->
     assert (sargs <> []);
     begin_def ();

compiler/syntax/src/res_core.ml

@@ -2374,15 +2374,9 @@ and parse_unary_expr p =
  * If you have `a + b`, `a` and `b` both represent
  * the operands of the binary expression with opeartor `+` *)
 and parse_operand_expr ~context p =
-  let start_pos = p.Parser.start_pos in
   let attrs = ref (parse_attributes p) in
   let expr =
     match p.Parser.token with
-    | Assert ->
-      Parser.next p;
-      let expr = parse_expr p in
-      let loc = mk_loc start_pos p.prev_end_pos in
-      Ast_helper.Exp.assert_ ~loc expr
     | Lident "async"
     (* we need to be careful when we're in a ternary true branch:
        `condition ? ternary-true-branch : false-branch`

compiler/syntax/src/res_grammar.ml

@@ -149,10 +149,10 @@ let is_atomic_typ_expr_start = function
   | _ -> false
 
 let is_expr_start = function
-  | Token.Assert | At | Await | Backtick | Bang | Codepoint _ | False | Float _
-  | For | Hash | If | Int _ | Lbrace | Lbracket | LessThan | Lident _ | List
-  | Lparen | Minus | MinusDot | Module | Percent | Plus | PlusDot | Bnot | Bor
-  | Bxor | Band | String _ | Switch | True | Try | Uident _
+  | Token.At | Await | Backtick | Bang | Codepoint _ | False | Float _ | For
+  | Hash | If | Int _ | Lbrace | Lbracket | LessThan | Lident _ | List | Lparen
+  | Minus | MinusDot | Module | Percent | Plus | PlusDot | Bnot | Bor | Bxor
+  | Band | String _ | Switch | True | Try | Uident _
   | Underscore (* _ => doThings() *)
   | While | Forwardslash | ForwardslashDot | Dict ->
     true
@@ -264,7 +264,7 @@ let is_attribute_start = function
 let is_jsx_child_start = is_atomic_expr_start
 
 let is_block_expr_start = function
-  | Token.Assert | At | Await | Backtick | Bang | Break | Codepoint _ | Continue
+  | Token.At | Await | Backtick | Bang | Break | Codepoint _ | Continue
   | Exception | False | Float _ | For | Forwardslash | ForwardslashDot | Hash
   | If | Int _ | Lbrace | Lbracket | LessThan | Let _ | Lident _ | List | Lparen
   | Minus | MinusDot | Module | Open | Percent | Plus | PlusDot | String _

compiler/syntax/src/res_token.ml

@@ -57,7 +57,6 @@ type t =
   | LessThan
   | Hash
   | HashEqual
-  | Assert
   | Tilde
   | Question
   | If
@@ -182,7 +181,6 @@ let to_string = function
   | Asterisk -> "*"
   | AsteriskDot -> "*."
   | Exponentiation -> "**"
-  | Assert -> "assert"
   | Tilde -> "~"
   | Question -> "?"
   | If -> "if"
@@ -234,7 +232,6 @@ let to_string = function
 let keyword_table = function
   | "and" -> And
   | "as" -> As
-  | "assert" -> Assert
   | "await" -> Await
   | "break" -> Break
   | "constraint" -> Constraint
@@ -267,7 +264,7 @@ let keyword_table = function
 [@@raises Not_found]
 
 let is_keyword = function
-  | Await | Break | Continue | And | As | Assert | Constraint | Else | Exception
+  | Await | Break | Continue | And | As | Constraint | Else | Exception
   | External | False | For | If | In | Include | Land | Let _ | List | Lor
   | Module | Mutable | Of | Open | Private | Rec | Switch | True | Try | Typ
   | When | While | Dict ->

compiler/syntax/src/res_token_debugger.ml

@@ -74,7 +74,6 @@ let dump_tokens filename =
       | Res_token.LessThan -> "LessThan"
       | Res_token.Hash -> "Hash"
       | Res_token.HashEqual -> "HashEqual"
-      | Res_token.Assert -> "Assert"
       | Res_token.Tilde -> "Tilde"
       | Res_token.Question -> "Question"
       | Res_token.If -> "If"

packages/@rescript/runtime/Pervasives.res

@@ -22,6 +22,8 @@ result == "Caught exception: Out of milk"
 */
 external throw: exn => 'a = "%raise"
 
+external assert: bool => 'a = "%assert"
+
 @deprecated({
   reason: "`raise` has been renamed to `throw` to align with JavaScript vocabulary. Please use `throw` instead",
   migrate: throw(),

tests/analysis_tests/tests-reanalyze/termination/src/TestCyberTruck.res

@@ -5,7 +5,7 @@ let progress = {
   let counter = ref((100))
   () => {
     if counter.contents < 0 {
-      assert false
+      assert(false)
     }
     counter := counter.contents - 1
   }
@@ -247,7 +247,7 @@ module UITermination = {
   let nothing: onClick = () => ()
 
   type div = (~text: string, ~onClick: onClick) => dom
-  let div: div = (~text, ~onClick) => assert false
+  let div: div = (~text, ~onClick) => assert(false)
 
   let initState = n => n == 0 ? Some(42) : None
   let increment = n => Some(n + 1)

tests/analysis_tests/tests/src/Objects.res

@@ -5,7 +5,7 @@ type nestedObjT = {"y": objT}
 module Rec = {
   type recordt = {xx: int, ss: string}
 
-  let recordVal: recordt = assert false
+  let recordVal: recordt = assert(false)
 }
 
 let object: objT = {"name": "abc", "age": 4}

tests/analysis_tests/tests/src/Patterns.res

@@ -13,7 +13,7 @@ module A = {
 
   type rec arr = A(array<arr>)
 
-  let A([v1, _, _]) | _ as v1 = assert false
+  let A([v1, _, _]) | _ as v1 = assert(false)
 
 }
 

tests/syntax_tests/data/parsing/grammar/expressions/binary.res

@@ -14,10 +14,8 @@ node :=
     node 
   }
 
-let x = z->switch z {| _ => false} 
-let x = z->@attr switch z {| _ => false} 
-let x = z->assert(z)
-let x = z->@attr assert(z)
+let x = z->switch z {| _ => false}
+let x = z->@attr switch z {| _ => false}
 let x = z->try sideEffect() catch { | _ => f() }
 let x = z->@attr try sideEffect() catch { | _ => f() }
 let x = z->for i in 0 to 10 { () }

tests/syntax_tests/data/parsing/grammar/expressions/expected/binary.res.txt

@@ -3,8 +3,6 @@
     [@attr ])
 let x = z -> (match z with | _ -> false)
 let x = z -> ((match z with | _ -> false)[@attr ])
-let x = z -> (assert z)
-let x = z -> ((assert z)[@attr ])
 let x = z -> (try sideEffect () with | _ -> f ())
 let x = z -> ((try sideEffect () with | _ -> f ())[@attr ])
 let x = z -> for i = 0 to 10 do () done

tests/syntax_tests/data/printer/comments/blockExpr.res

@@ -357,16 +357,13 @@ if {
   true
 } // trailing
 
+// here
 assert({
-  // here 
   open /* inside */ Matrix
   // c
 
   // c2
   compare(m1, m2)
-  // after
-
-  // test
 })
 
 user.name = {

tests/syntax_tests/data/printer/comments/expected/blockExpr.res.txt

@@ -354,16 +354,13 @@ if {
   true
 } // trailing
 
+// here
 assert({
-  // here
   open /* inside */ Matrix
   // c
 
   // c2
   compare(m1, m2)
-  // after
-
-  // test
 })
 
 user.name = {

tests/syntax_tests/data/printer/expr/assert.res

@@ -1,56 +1,56 @@
-assert false
-
-assert truth
-
-let x = assert true
-let x = assert 12
-let x = assert (12: int)
-let x = assert 12
-let x = assert list{1, 2, ...x}
-let x = assert module(Foo: Bar)
-let x = assert module(Foo)
-let x = assert Rgb(1, 2, 3)
-let x = assert [a, b, c]
-let x = assert {x: 1, y: 3}
-let x = assert (1, 2, 3)
-let x = assert %extension
-let x = assert user.name
-let x = assert streets[0]
-let x = assert apply(arg1, arg2)
-let x = assert apply(arg1, arg2)
-let x = assert -1
-let x = assert !true
-let x = assert (x => print(x))
-let x = assert (switch x {
+assert(false)
+
+assert(truth)
+
+let x = assert(true)
+let x = assert(12)
+let x = assert(12: int)
+let x = assert(12)
+let x = assert(list{1, 2, ...x})
+let x = assert(module(Foo: Bar))
+let x = assert(module(Foo))
+let x = assert(Rgb(1, 2, 3))
+let x = assert([a, b, c])
+let x = assert({x: 1, y: 3})
+let x = assert((1, 2, 3))
+let x = assert(%extension)
+let x = assert(user.name)
+let x = assert(streets[0])
+let x = assert(apply(arg1, arg2))
+let x = assert(apply(arg1, arg2))
+let x = assert(-1)
+let x = assert(!true)
+let x = assert(x => print(x))
+let x = assert(switch x {
   | Blue => ()
   | Yello => ()
 })
 
-let x = assert (for i in 0 to 10 {
+let x = assert(for i in 0 to 10 {
   print_int(i)
 })
 
-let x = assert (if i < 10 {
+let x = assert(if i < 10 {
   print_int(i)
 } else {
   print_int(1000)
 })
 
-let x = assert (while i < 10 {
+let x = assert(while i < 10 {
   print_int(i)
 })
 
-let x = assert (try sideEffect() catch {| Exit => ()})
+let x = assert(try sideEffect() catch {| Exit => ()})
 
-let x = assert (@attr expr)
+let x = assert(@attr expr)
 
-let x = assert (a + b)
+let x = assert(a + b)
 
-let x = @attr assert false
+let x = @attr assert(false)
 
-assert invariant["fatal"]
-assert invariants[0]
+assert(invariant["fatal"])
+assert(invariants[0])
 
-assert address["street"] = "Brusselsestraat"
+assert(address["street"] = "Brusselsestraat")
 
-assert (true ? 0 : 1)
+assert(true ? 0 : 1)

tests/syntax_tests/data/printer/expr/expected/assert.res.txt

@@ -4,7 +4,7 @@ assert(truth)
 
 let x = assert(true)
 let x = assert(12)
-let x = assert(12: int)
+let x = assert((12: int))
 let x = assert(12)
 let x = assert(list{1, 2, ...x})
 let x = assert(module(Foo: Bar))
@@ -21,28 +21,38 @@ let x = assert(apply(arg1, arg2))
 let x = assert(-1)
 let x = assert(!true)
 let x = assert(x => print(x))
-let x = assert(switch x {
-| Blue => ()
-| Yello => ()
-})
-
-let x = assert(for i in 0 to 10 {
-  print_int(i)
-})
-
-let x = assert(if i < 10 {
-  print_int(i)
-} else {
-  print_int(1000)
-})
-
-let x = assert(while i < 10 {
-  print_int(i)
-})
-
-let x = assert(try sideEffect() catch {
-| Exit => ()
-})
+let x = assert(
+  switch x {
+  | Blue => ()
+  | Yello => ()
+  },
+)
+
+let x = assert(
+  for i in 0 to 10 {
+    print_int(i)
+  },
+)
+
+let x = assert(
+  if i < 10 {
+    print_int(i)
+  } else {
+    print_int(1000)
+  },
+)
+
+let x = assert(
+  while i < 10 {
+    print_int(i)
+  },
+)
+
+let x = assert(
+  try sideEffect() catch {
+  | Exit => ()
+  },
+)
 
 let x = assert(@attr expr)