Use the same keyword 'type' for adt definitions

examples/example.bend

@@ -19,15 +19,15 @@
 
 # You can use numbers on the native match expression
 # The `+` arm binds the `scrutinee`-1 variable to the value of the number -1
-(Num.pred) = λn 
-  switch n { 
+(Num.pred) = λn
+  switch n {
     0: 0
     _: n-1
   }
 
 # Write new data types like this
-data Option = (Some val) | None
-data Bool = True | False
+type Option = (Some val) | None
+type Bool = True | False
 
 # You can have pattern matching on definitions
 # Use `*` to ignore a pattern
@@ -46,7 +46,7 @@ data Bool = True | False
   }
 
 # Data types can store values
-data Boxed = (Box val)
+type Boxed = (Box val)
 
 # Types with only one constructor can be destructured using `let` or a single matching definition
 (Box.map (Boxed/Box val) f) = (Boxed/Box (f val))
@@ -71,7 +71,7 @@ data Boxed = (Box val)
 # You can execute a program in HVM with "cargo run -- run <path to file>"
 # Other options are "check" (the default mode) to just see if the file is well formed
 # and "compile" to output hvm-core code.
-(main) = 
+(main) =
   let tup = (Tuple.new Option/None (Num.pred 5))
 
   let fst = (Tuple.fst tup)

examples/quick_sort.bend

@@ -1,4 +1,4 @@
-data Tree = Leaf | (Node l m r)
+type Tree = Leaf | (Node l m r)
 
 # Parallel QuickSort
 (Sort List/Nil)         = Tree/Leaf

examples/radix_sort.bend

@@ -1,5 +1,5 @@
-data Map_ = Free | Used | (Both a b)
-data Arr = Null | (Leaf x) | (Node a b)
+type Map_ = Free | Used | (Both a b)
+type Arr = Null | (Leaf x) | (Node a b)
 
 (Swap s a b) = switch s {
   0: (Map_/Both a b)

src/fun/builtins.bend

@@ -1,11 +1,11 @@
-data String = (Nil) | (Cons head ~tail)
-data List   = (Nil) | (Cons head ~tail)
-data Result = (Ok val) | (Err val)
-data Nat    = (Succ ~pred) | (Zero)
+type String = (Nil) | (Cons head ~tail)
+type List   = (Nil) | (Cons head ~tail)
+type Result = (Ok val) | (Err val)
+type Nat    = (Succ ~pred) | (Zero)
 
 # MAP Impl
 
-data Map = (Node value ~left ~right) | (Leaf)
+type Map = (Node value ~left ~right) | (Leaf)
 
 Map/empty = Map/Leaf
 
@@ -60,7 +60,7 @@ IO_GET_TIME_TAG   = 5
 IO_SLEEP_TAG      = 6
 IO_DRAW_IMAGE_TAG = 7
 
-data IO
+type IO
   = (Done term)
   | (PutText   text      cont)
   | (GetText             cont)

src/fun/parser.rs

@@ -66,17 +66,6 @@ impl<'a> TermParser<'a> {
     while !self.is_eof() {
       let ini_idx = *self.index();
 
-      // Imp type definition
-      if self.try_parse_keyword("type") {
-        let mut prs = PyParser { input: self.input, index: *self.index() };
-        let (enum_, nxt_indent) = prs.parse_type(indent)?;
-        self.index = prs.index;
-        let end_idx = *self.index();
-        prs.add_type(enum_, &mut book, ini_idx, end_idx, builtin)?;
-        indent = nxt_indent;
-        last_rule = None;
-        continue;
-      }
       // Imp record type definition
       if self.try_parse_keyword("object") {
         let mut prs = PyParser { input: self.input, index: *self.index() };
@@ -101,14 +90,31 @@ impl<'a> TermParser<'a> {
         continue;
       }
 
-      // Fun type definition
-      if self.try_parse_keyword("data") {
-        let (nam, adt) = self.parse_datatype(builtin)?;
-        let end_idx = *self.index();
-        self.with_ctx(book.add_adt(nam, adt), ini_idx, end_idx)?;
-        indent = self.advance_newlines();
-        last_rule = None;
-        continue;
+      // Fun/Imp type definition
+      if self.try_parse_keyword("type") {
+        self.skip_trivia();
+        let rewind_index = self.index;
+
+        let _ = self.labelled(|p| p.parse_top_level_name(), "datatype name")?;
+
+        if self.starts_with(":") {
+          let mut prs = PyParser { input: self.input, index: rewind_index };
+          let (r#enum, nxt_indent) = prs.parse_type(indent)?;
+          self.index = prs.index;
+          let end_idx = *self.index();
+          prs.add_type(r#enum, &mut book, ini_idx, end_idx, builtin)?;
+          indent = nxt_indent;
+          last_rule = None;
+          continue;
+        } else {
+          self.index = rewind_index;
+          let (nam, adt) = self.parse_datatype(builtin)?;
+          let end_idx = *self.index();
+          self.with_ctx(book.add_adt(nam, adt), ini_idx, end_idx)?;
+          indent = self.advance_newlines();
+          last_rule = None;
+          continue;
+        }
       }
 
       // Fun function definition

src/imp/parser.rs

@@ -962,14 +962,7 @@ impl<'a> PyParser<'a> {
     let mut variants = Vec::new();
     let mut nxt_indent = indent;
     while nxt_indent == indent {
-      let ctr_name = self.parse_top_level_name()?;
-      let ctr_name = Name::new(format!("{typ_name}/{ctr_name}"));
-      let mut fields = Vec::new();
-      self.skip_trivia_inline();
-      if self.starts_with("{") {
-        fields = self.list_like(|p| p.parse_variant_field(), "{", "}", ",", true, 0)?;
-      }
-      variants.push(Variant { name: ctr_name, fields });
+      variants.push(self.parse_enum_variant(&typ_name)?);
       if !self.is_eof() {
         self.consume_new_line()?;
       }
@@ -981,6 +974,17 @@ impl<'a> PyParser<'a> {
     Ok((enum_, nxt_indent))
   }
 
+  pub fn parse_enum_variant(&mut self, typ_name: &Name) -> ParseResult<Variant> {
+    let ctr_name = self.parse_top_level_name()?;
+    let ctr_name = Name::new(format!("{typ_name}/{ctr_name}"));
+    let mut fields = Vec::new();
+    self.skip_trivia_inline();
+    if self.starts_with("{") {
+      fields = self.list_like(|p| p.parse_variant_field(), "{", "}", ",", true, 0)?;
+    }
+    Ok(Variant { name: ctr_name, fields })
+  }
+
   pub fn parse_object(&mut self, indent: Indent) -> ParseResult<(Variant, Indent)> {
     if indent != Indent::Val(0) {
       let msg = "Indentation error. Types defined with 'object' must be at the start of the line.";

tests/golden_tests/cli/compile_all.bend

@@ -1,4 +1,4 @@
-data Pair
+type Pair
   = (Pair fst snd)
 
 Pair.get f (Pair/Pair fst snd) = (f fst snd)

tests/golden_tests/cli/debug_u60_to_nat.bend

@@ -1,4 +1,4 @@
-data Nat_ = (Z) | (S nat)
+type Nat_ = (Z) | (S nat)
 
 U60ToNat n = switch n {
   0: Nat_/Z

tests/golden_tests/cli/desugar_bool_scott.bend

@@ -1,3 +1,3 @@
-data Boolean = True | False
+type Boolean = True | False
 
 main = Boolean/True

tests/golden_tests/cli/net_size_too_large.bend

@@ -1,5 +1,5 @@
-data Map_ = Free | Used | (Both a b)
-data Arr = Null | (Leaf x) | (Node a b)
+type Map_ = Free | Used | (Both a b)
+type Arr = Null | (Leaf x) | (Node a b)
 
 (Swap s a b) = switch s {
   0: (Map_/Both a b)

tests/golden_tests/cli/no_check_net_size.bend

@@ -1,5 +1,5 @@
-data Map_ = Free | Used | (Both a b)
-data Arr = Null | (Leaf x) | (Node a b)
+type Map_ = Free | Used | (Both a b)
+type Arr = Null | (Leaf x) | (Node a b)
 
 (Swap s a b) = switch s {
   0: (Map_/Both a b)

tests/golden_tests/cli/warn_and_err.bend

@@ -1,3 +1,3 @@
 Foo a a = a
 
-Main = (Foo a)
+Main = (Foo a)

tests/golden_tests/compile_file/error_data_def_name.bend

@@ -1,4 +1,4 @@
-data A = A
+type A = A
 A/A = 0
 
 main = A/A

tests/golden_tests/compile_file/just_data.bend

@@ -1 +1 @@
-data
+type

tests/golden_tests/compile_file/missing_adt_eq.bend

@@ -1 +1 @@
-data Adt
+type Adt

tests/golden_tests/compile_file/missing_ctrs.bend

@@ -1 +1 @@
-data Adt = 
+type Adt =

tests/golden_tests/compile_file/nested_ctr_wrong_arity.bend

@@ -1,5 +1,5 @@
-data Pair = (Pair fst snd)
+type Pair = (Pair fst snd)
 
 fst_fst (Pair/Pair (Pair/Pair fst) *) = fst
 
-main = (fst_fst (Pair/Pair (Pair/Pair 1 2) 3))
+main = (fst_fst (Pair/Pair (Pair/Pair 1 2) 3))

tests/golden_tests/compile_file/redex_order_recursive.bend

@@ -1,4 +1,4 @@
-data Tree = (node lft rgt) | (leaf val)
+type Tree = (node lft rgt) | (leaf val)
 
 tail_recursive = @x (x @pred @acc (tail_recursive pred (+ 1 acc)) @acc 0)
 

tests/golden_tests/compile_file/wrong_ctr_arity.bend

@@ -1,4 +1,4 @@
-data Boxed = (Box val)
+type Boxed = (Box val)
 
 Bar (*, (Boxed/Box x y)) = x
 

tests/golden_tests/compile_file/wrong_ctr_var_arity.bend

@@ -1,4 +1,4 @@
-data Tup = (pair a b)
+type Tup = (pair a b)
 
 (foo Tup/pair) = pair
 

tests/golden_tests/compile_file_o_all/adt_option_and.bend

@@ -1,4 +1,4 @@
-data Option = (Some val) | None
+type Option = (Some val) | None
 
 Option/and = @a @b match a {
   Option/Some: match b {

tests/golden_tests/compile_file_o_all/adt_string.bend

@@ -1,3 +1,3 @@
-data String = S
+type String = S
 
 main = String/S

tests/golden_tests/compile_file_o_all/and.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 and a bool/false = bool/false
 and a bool/true = a

tests/golden_tests/compile_file_o_all/expr.bend

@@ -1,4 +1,4 @@
-data Expr
+type Expr
   = (Var name)
   | (Num val)
   | (App fun arg)
@@ -9,7 +9,7 @@ data Expr
   | (Tup fst snd)
   | (Op2 op fst snd)
 
-data Op
+type Op
   = Add
   | Sub
   | Mul

tests/golden_tests/compile_file_o_all/list_merge_sort.bend

@@ -1,5 +1,5 @@
-data Bool = True | False
-data List_ = (Cons head tail) | Nil
+type Bool = True | False
+type List_ = (Cons head tail) | Nil
 
 If Bool/True then else = then
 If Bool/False then else = else

tests/golden_tests/compile_file_o_all/list_reverse.bend

@@ -1,4 +1,4 @@
-data list = (cons h t) | nil
+type list = (cons h t) | nil
 
 reverse (list/cons h t) = (concat (reverse t) (list/cons h list/nil))
 reverse list/nil = list/nil

tests/golden_tests/compile_file_o_all/match_adt_non_exhaustive.bend

@@ -1,4 +1,4 @@
-data Maybe = (Some val) | None
+type Maybe = (Some val) | None
 
 main = @maybe
   match maybe {

tests/golden_tests/compile_file_o_all/match_dup_and_reconstruction.bend

@@ -1,4 +1,4 @@
-data Box = (Boxed val)
+type Box = (Boxed val)
 
 Got = @a match a {
   Box/Boxed: (a, a.val)

tests/golden_tests/compile_file_o_all/non_exhaustive_and.bend

@@ -1,4 +1,4 @@
-data Bool = T | F
+type Bool = T | F
 
 Bool.and Bool/T Bool/T = Bool/T
 Bool.and Bool/F Bool/F = Bool/F

tests/golden_tests/compile_file_o_all/non_exhaustive_different_types.bend

@@ -1,10 +1,10 @@
 # There was a bug where it would say "Non-exhaustive pattern (foo f1 f2 f3 f3)",
 # repeating the missing constructor for the next args.
 
-data b1 = f1 | t1
-data b2 = f2 | t2
-data b3 = f3 | t3
-data b4 = f4 | t4
+type b1 = f1 | t1
+type b2 = f2 | t2
+type b3 = f3 | t3
+type b4 = f4 | t4
 
 (foo b1/f1 b2/f2 b3/f3 b4/f4) = 0
 (foo b1/f1 b2/f2 b3/f3 b4/t4) = 1

tests/golden_tests/compile_file_o_all/non_exhaustive_pattern.bend

@@ -1,4 +1,4 @@
-data Type = A | B | C | D
+type Type = A | B | C | D
 
 Foo Type/A Type/B Type/C Type/D = 0
 Foo Type/A Type/B Type/D Type/D = 1

tests/golden_tests/compile_file_o_all/non_exhaustive_tree.bend

@@ -1,4 +1,4 @@
-data Tree = (Leaf a) | (Both a b)
+type Tree = (Leaf a) | (Both a b)
 (Warp s (Tree/Leaf a)   (Tree/Leaf b))   = 0
 (Warp s (Tree/Both a b) (Tree/Both c d)) = 1
 

tests/golden_tests/compile_file_o_all/num_pattern_with_var.bend

@@ -1,5 +1,5 @@
 # We had a bug where this gave the incorrect error: "Expected a number but found 'a' at definition 'Foo'."
-data bool = false | true
+type bool = false | true
 
 (Foo bool/false a) = 0
 (Foo bool/true 0) = 0

tests/golden_tests/compile_file_o_all/scrutinee_reconstruction.bend

@@ -1,4 +1,4 @@
-data Option = (Some val) | None
+type Option = (Some val) | None
 
 Option/or = @a @b match a {
   Option/Some: a

tests/golden_tests/compile_file_o_all/weekday.bend

@@ -1,4 +1,4 @@
-data Weekday
+type Weekday
   = Monday
   | Tuesday
   | Wednesday

tests/golden_tests/compile_file_o_no_all/bitonic_sort.bend

@@ -1,5 +1,5 @@
-data Tree = (Leaf a) | (Both a b)
-data Error = Err
+type Tree = (Leaf a) | (Both a b)
+type Error = Err
 
 # Atomic Swapper
 (Swap n a b) = switch n {

tests/golden_tests/compile_file_o_no_all/list_reverse.bend

@@ -1,4 +1,4 @@
-data list = (cons h t) | nil
+type list = (cons h t) | nil
 
 reverse (list/cons h t) = (concat (reverse t) (list/cons h list/nil))
 reverse list/nil = list/nil

tests/golden_tests/compile_file_o_no_all/sum_tree.bend

@@ -1,4 +1,4 @@
-data Tree = (Leaf x) | (Node x0 x1)
+type Tree = (Leaf x) | (Node x0 x1)
 
 add = λa λb (+ a b)
 

tests/golden_tests/desugar_file/deref_loop.bend

@@ -1,4 +1,4 @@
-data nat = (succ pred) | zero
+type nat = (succ pred) | zero
 
 foo = @x match x {
   nat/succ: x.pred

tests/golden_tests/desugar_file/non_exaustive_limit.bend

@@ -1,4 +1,4 @@
-data Foo = A | B | C | D | E | F | G | H
+type Foo = A | B | C | D | E | F | G | H
 
 Bar Foo/A Foo/A Foo/A = *
 

tests/golden_tests/encode_pattern_match/adt_tup_era.bend

@@ -1,4 +1,4 @@
-data Tuple = (Pair a b)
+type Tuple = (Pair a b)
 
 (Foo (Tuple/Pair (Tuple/Pair a b) c)) = a
 (Foo *) = 2

tests/golden_tests/encode_pattern_match/and3.bend

@@ -1,4 +1,4 @@
-data Bool = T | F
+type Bool = T | F
 
 And (Bool/T, Bool/T, Bool/T) = Bool/T
 And * = Bool/F

tests/golden_tests/encode_pattern_match/bool.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 not bool/false = bool/true
 not bool/true = bool/false

tests/golden_tests/encode_pattern_match/bool_tup.bend

@@ -1,4 +1,4 @@
-data Bool = T | F
+type Bool = T | F
 
 foo (Bool/T, x) = x
 foo * = Bool/F

tests/golden_tests/encode_pattern_match/box.bend

@@ -1,4 +1,4 @@
-data box = (new val)
+type box = (new val)
 
 unbox (box/new val) = val
 unbox x = x

tests/golden_tests/encode_pattern_match/common.bend

@@ -1,24 +1,24 @@
-data Box
+type Box
   = (Filled value)
   | Empty
 
-data Option
+type Option
   = (Some x)
   | None
 
-data Result_
+type Result_
   = (Ok a)
   | (Err b)
 
-data List_
+type List_
   = (Cons x xs)
   | Nil
 
-data Bool = True | False
+type Bool = True | False
 
-data Light = Red | Yellow | Green
+type Light = Red | Yellow | Green
 
-data Direction
+type Direction
   = North
   | South
   | East

tests/golden_tests/encode_pattern_match/definition_merge.bend

@@ -1,5 +1,5 @@
-data Either = (Left value) | (Right value)
-data Bool = Bool/True | Bool/False
+type Either = (Left value) | (Right value)
+type Bool = Bool/True | Bool/False
 
 Foo (Either/Left  Bool/False) (Either/Left  Bool/False) = 1
 Foo (Either/Left  Bool/False) (Either/Left  Bool/True)  = 1

tests/golden_tests/encode_pattern_match/expr.bend

@@ -1,4 +1,4 @@
-data Expr
+type Expr
   = (Var name)
   | (Num val)
   | (App fun arg)
@@ -9,7 +9,7 @@ data Expr
   | (Tup fst snd)
   | (Op2 op fst snd)
 
-data Op
+type Op
   = Add
   | Sub
   | Mul

tests/golden_tests/encode_pattern_match/is_some_some.bend

@@ -1,4 +1,4 @@
-data Option = (Some x) | (None)
+type Option = (Some x) | (None)
 
 some_some (Option/Some (Option/Some x)) = 1
 some_some *                             = 0

tests/golden_tests/encode_pattern_match/list_merge_sort.bend

@@ -1,5 +1,5 @@
-data Bool = True | False
-data List_ = (Cons head tail) | Nil
+type Bool = True | False
+type List_ = (Cons head tail) | Nil
 
 If Bool/True then else = then
 If Bool/False then else = else
@@ -26,4 +26,4 @@ Merge cmp (List_/Cons xh xt) (List_/Cons yh yt) =
     (List_/Cons xh (Merge cmp xt ys))
     let xs = (List_/Cons xh xt)
     (List_/Cons yh (Merge cmp xs yt))
-  )
+  )

tests/golden_tests/encode_pattern_match/match_adt_unscoped_in_arm.bend

@@ -1,5 +1,5 @@
 # Test that we don't mess up with that unscoped lambda/var
-data bool = T | F
+type bool = T | F
 
 main = @x match x {
   Bool/T: @$x $x

tests/golden_tests/encode_pattern_match/match_adt_unscoped_lambda.bend

@@ -1,4 +1,4 @@
-data Maybe = None | (Some val)
+type Maybe = None | (Some val)
 
 main = (match x = (Maybe/Some 1) {
   Maybe/None: @$x *

tests/golden_tests/encode_pattern_match/match_adt_unscoped_var.bend

@@ -1,4 +1,4 @@
-data Maybe = None | (Some val)
+type Maybe = None | (Some val)
 
 Foo = @$x match x = (Maybe/Some 1) {
   Maybe/None: $x

tests/golden_tests/encode_pattern_match/match_num_adt_tup_parser.bend

@@ -1,5 +1,5 @@
 # Testing various forms of pattern matching
-data Result_ = (Ok val) | (Err err)
+type Result_ = (Ok val) | (Err err)
 
 Parse state (String/Cons '(' xs) = (Result_/Ok ('(', xs, state))
 Parse state (String/Cons ')' xs) = (Result_/Ok (')', xs, state))

tests/golden_tests/encode_pattern_match/match_syntax.bend

@@ -1,4 +1,4 @@
-data List_ = (Cons x xs) | (Nil)
+type List_ = (Cons x xs) | (Nil)
 
 head x =
   match x {

tests/golden_tests/encode_pattern_match/non_matching_fst_arg.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 Foo x bool/false = x
 Foo x bool/true = (Foo x x)

tests/golden_tests/encode_pattern_match/pattern_match_encoding.bend

@@ -1,4 +1,4 @@
-data MyType = (A a) | (B b) | (C c) | (D d1 d2) | (E e1 e2)
+type MyType = (A a) | (B b) | (C c) | (D d1 d2) | (E e1 e2)
 
 Foo (MyType/A a) = 100
 Foo * = 200

tests/golden_tests/encode_pattern_match/var_only.bend

@@ -1,4 +1,4 @@
-data Bool = False | True
+type Bool = False | True
 
 (Foo a b) = λf (f a)
 (Foo a b) = b

tests/golden_tests/encode_pattern_match/weekday.bend

@@ -1,4 +1,4 @@
-data Weekday
+type Weekday
   = Monday
   | Tuesday
   | Wednesday

tests/golden_tests/mutual_recursion/odd_even.bend

@@ -1,4 +1,4 @@
-data Bool = True | False
+type Bool = True | False
 
 (if_ 0 then else) = else
 (if_ _ then else) = then

tests/golden_tests/parse_file/redefinition_with_type_between.bend

@@ -1,3 +1,3 @@
 A = 0
-data B = B
-A = 1
+type B = B
+A = 1

tests/golden_tests/parse_file/repeated_adt_name.bend

@@ -1,4 +1,4 @@
-data Foo = A
-data Foo = B
+type Foo = A
+type Foo = B
 
 main = *

tests/golden_tests/run_file/adt_match.bend

@@ -1,4 +1,4 @@
-data Opt = (Some x) | None
+type Opt = (Some x) | None
 
 Opt/map = @opt @f
   match opt {

tests/golden_tests/run_file/adt_match_wrong_tag.bend

@@ -1,3 +1,3 @@
-data Option = (Some val) | None
+type Option = (Some val) | None
 
 main = λa #Option (a #wrong_tag λb b *)

tests/golden_tests/run_file/adt_option_and.bend

@@ -1,4 +1,4 @@
-data Option = (Some val) | None
+type Option = (Some val) | None
 
 main = @a @b match a {
   Option/Some: match b {

tests/golden_tests/run_file/adt_wrong_tag.bend

@@ -1,3 +1,3 @@
-data Option = (Some val) | None
+type Option = (Some val) | None
 
-main = (@a #Option (a #wrong_tag @x x *)) 
+main = (@a #Option (a #wrong_tag @x x *))

tests/golden_tests/run_file/and.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 and a bool/false = bool/false
 and a bool/true = a

tests/golden_tests/run_file/bend_fold.bend

@@ -1,5 +1,5 @@
 # should return (a+b+c) * 2^depth
-data Tree = (node ~lft ~rgt) | (leaf val)
+type Tree = (node ~lft ~rgt) | (leaf val)
 
 main =
   let depth = 2

tests/golden_tests/run_file/bitonic_sort.bend

@@ -1,5 +1,5 @@
-data Tree = (Leaf a) | (Both a b)
-data Error = Err
+type Tree = (Leaf a) | (Both a b)
+type Error = Err
 
 # Atomic Swapper
 (Swap n a b) = switch n {

tests/golden_tests/run_file/box.bend

@@ -1,4 +1,4 @@
-data _Box = (Box val)
+type _Box = (Box val)
 
 Box.subst (_Box/Box x) cmp to = switch _ = (cmp x) {
   0: (_Box/Box x)

tests/golden_tests/run_file/def_bool_num.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 go bool/true  0 = 1
 go bool/false _ = 0

tests/golden_tests/run_file/def_num_bool.bend

@@ -1,4 +1,4 @@
-data bool = true | false
+type bool = true | false
 
 go 0 bool/true  = 1
 go 0 bool/false = 0

tests/golden_tests/run_file/example.bend

@@ -19,15 +19,15 @@
 
 # You can use numbers on the native match expression
 # The `+` arm binds the `scrutinee`-1 variable to the the value of the number -1
-(Num.pred) = λn 
-  switch n { 
+(Num.pred) = λn
+  switch n {
     0: 0
     _: n-1
   }
 
 # Write new data types like this
-data Option = (Some val) | None
-data Bool = True | False
+type Option = (Some val) | None
+type Bool = True | False
 
 # You can have pattern matching on definitions
 # Use `*` to ignore a pattern
@@ -46,7 +46,7 @@ data Bool = True | False
   }
 
 # Data types can store values
-data Boxed = (Box val)
+type Boxed = (Box val)
 
 # Types with only one constructor can be destructured using `let` or a single matching definition
 (Box.map (Boxed/Box val) f) = (Boxed/Box (f val))
@@ -71,7 +71,7 @@ data Boxed = (Box val)
 # You can execute a program in HVM with "cargo run -- run <path to file>"
 # Other options are "check" (the default mode) to just see if the file is well formed
 # and "compile" to output hvm-core code.
-(main) = 
+(main) =
   let tup = (Tuple.new Option/None (Num.pred 5))
 
   let fst = (Tuple.fst tup)

tests/golden_tests/run_file/list_reverse.bend

@@ -1,4 +1,4 @@
-data list = (cons h t) | nil
+type list = (cons h t) | nil
 
 reverse (list/cons h t) = (concat (reverse t) (list/cons h list/nil))
 reverse list/nil = list/nil

tests/golden_tests/run_file/match_num_adt_tup_parser.bend

@@ -1,5 +1,5 @@
 # Testing various forms of pattern matching
-data Result_ = (Ok val) | (Err err)
+type Result_ = (Ok val) | (Err err)
 
 Parse state (String/Cons '{' xs) = (Result_/Ok ('{', xs, state))
 Parse state (String/Cons '}' xs) = (Result_/Ok ('}', xs, state))

tests/golden_tests/run_file/merge_sort.bend

@@ -1,12 +1,12 @@
-data Tree = (Leaf x) | (Node x0 x1) 
-data List_ = Nil | (Cons h t)
+type Tree = (Leaf x) | (Node x0 x1)
+type List_ = Nil | (Cons h t)
 
 sort (Tree/Leaf v) = (List_/Cons v List_/Nil)
 sort (Tree/Node a b) = (merge (sort a) (sort b))
 
 merge (List_/Nil) b = b
 merge (List_/Cons x xs) (List_/Nil) = (List_/Cons x xs)
-merge (List_/Cons x xs) (List_/Cons y ys) = 
+merge (List_/Cons x xs) (List_/Cons y ys) =
   let t = switch _ = (< x y) {
     0: λaλbλcλt(t c a b)
     _: λaλbλcλt(t a b c)

tests/golden_tests/run_file/mixed_syntax.bend

@@ -2,7 +2,7 @@ type Bool:
   True
   False
 
-data Tree = (node ~lft ~rgt) | (leaf val)
+type Tree = (node ~lft ~rgt) | (leaf val)
 
 def tree_xor(tree):
   fold tree:
@@ -21,6 +21,6 @@ main =
     when (< n depth):
       (Tree/node (fork (+ n 1)) (fork (+ n 1)))
     else:
-      if (% n 2) { (Tree/leaf Bool/True) } else { (Tree/leaf Bool/False) }  
+      if (% n 2) { (Tree/leaf Bool/True) } else { (Tree/leaf Bool/False) }
   }
   (tree_xor tree)

tests/golden_tests/run_file/names_hyphen.bend

@@ -1,6 +1,6 @@
 id cool-var-name = cool-var-name
 
-data Done_ = (Done done-var)
+type Done_ = (Done done-var)
 
 toZero n =
   switch n {

tests/golden_tests/run_file/names_hyphen_toplevel.bend

@@ -1,4 +1,4 @@
-data Foo-Bar = (Baz-Qux field-hyph)
+type Foo-Bar = (Baz-Qux field-hyph)
 
 fun-with-hyphen = 1
 

tests/golden_tests/run_file/open.bend

@@ -1,4 +1,4 @@
-data Pair = (new a b)
+type Pair = (new a b)
 
 type State:
   new { a, b }
@@ -10,4 +10,4 @@ def with_state(x, s):
 main =
   let x = (with_state @x x (State/new 1 2))
   open Pair x;
-  {x.a x.b}
+  {x.a x.b}

tests/golden_tests/run_file/radix_sort_ctr.bend

@@ -1,5 +1,5 @@
-data Map_ = Free | Used | (Both a b)
-data Arr = Null | (Leaf x) | (Node a b)
+type Map_ = Free | Used | (Both a b)
+type Arr = Null | (Leaf x) | (Node a b)
 
 (Swap s a b) = switch s {
   0: (Map_/Both a b)

tests/golden_tests/run_file/readback_list_other_ctr.bend

@@ -1,5 +1,5 @@
 # Check that the ctr in the middle are interpreted correctly
-data tup = (pair a b)
+type tup = (pair a b)
 
 main = (List/Cons
   (String/Cons 'a' (tup/pair 'b' (String/Cons 'c' String/Nil)))

tests/golden_tests/run_file/sum_tree.bend

@@ -1,4 +1,4 @@
-data Tree = (Leaf x) | (Node x0 x1)
+type Tree = (Leaf x) | (Node x0 x1)
 
 add = λa λb (+ a b)
 
@@ -13,4 +13,4 @@ sum = λt
     Tree/Node: (add (sum t.x0) (sum t.x1))
   }
 
-main = (sum (gen 8))
+main = (sum (gen 8))

tests/golden_tests/run_file/superposed_is_even.bend

@@ -1,5 +1,5 @@
-data N = (S pred) | Z
-data B = T | F
+type N = (S pred) | Z
+type B = T | F
 
 (Not B/T) = B/F
 (Not B/F) = B/T

tests/golden_tests/run_file/unscoped_never_used.bend

@@ -1,4 +1,4 @@
-data Bool = T | F
+type Bool = T | F
 
 main = @x match x {
   Bool/T : @$x *

tests/golden_tests/scott_triggers_unused/test.bend

@@ -8,6 +8,6 @@
 # This was happening because the prune algorithm was just collecting constructors
 # by searching for tags.
 
-data bool = t | f
+type bool = t | f
 
 main = @b match b { bool/t: 0; bool/f: 1}

tests/golden_tests/simplify_matches/adt_tup_era.bend

@@ -1,4 +1,4 @@
-data Tuple = (Pair a b)
+type Tuple = (Pair a b)
 
 (Foo (Tuple/Pair (Tuple/Pair a b) c)) = a
 (Foo *) = 2

tests/golden_tests/simplify_matches/already_flat.bend

@@ -1,6 +1,6 @@
-data Foo = CtrA | (CtrB x)
-data Bar = (CtrA1 a) | (CtrA2 a1 a2) | (CtrA3 a)
-data Baz = (CtrB0) | (CtrB1 b) | (CtrB2 b) | (CtrB3 b)
+type Foo = CtrA | (CtrB x)
+type Bar = (CtrA1 a) | (CtrA2 a1 a2) | (CtrA3 a)
+type Baz = (CtrB0) | (CtrB1 b) | (CtrB2 b) | (CtrB3 b)
 
 Rule1 = λx x
 

tests/golden_tests/simplify_matches/bits_dec.bend

@@ -1,4 +1,4 @@
-data Data/Bits = e | (o t) | (i t)
+type Data/Bits = e | (o t) | (i t)
 
 Data.Bits.dec Data/Bits/e = (Data/Bits/e)
 Data.Bits.dec (Data/Bits/o (Data/Bits/e)) = (Data/Bits/e)

tests/golden_tests/simplify_matches/complex_with_case.bend

@@ -1,11 +1,11 @@
-data Tree = (Node lt rt rd ld) | (Leaf val)
+type Tree = (Node lt rt rd ld) | (Leaf val)
 
 (map) =
   λarg1 λarg2 use tree = arg2;
   use f = arg1;
-  match tree with f { 
-    Tree/Node: (Tree/Node (map f tree.lt) (map f tree.rt) (map f tree.rd) (map f tree.ld)); 
-    Tree/Leaf: (Tree/Leaf (f tree.val)); 
+  match tree with f {
+    Tree/Node: (Tree/Node (map f tree.lt) (map f tree.rt) (map f tree.rd) (map f tree.ld));
+    Tree/Leaf: (Tree/Leaf (f tree.val));
   }
 
 main = map

tests/golden_tests/simplify_matches/double_unwrap_box.bend

@@ -1,5 +1,5 @@
 # Should notice that the second rule is redundant, not create flattened rule for it and not forward the second argument.
-data Boxed = (Box x)
+type Boxed = (Box x)
 
 (DoubleUnbox (Boxed/Box (Boxed/Box x)) *) = x
 (DoubleUnbox * x) = x

tests/golden_tests/simplify_matches/double_unwrap_maybe.bend

@@ -1,5 +1,5 @@
 # We want to make sure that the default value is not mistakenly erased in the first level of flattening.
-data Maybe = (Some x) | None
+type Maybe = (Some x) | None
 
 (DoubleUnwrap (Maybe/Some (Maybe/Some x)) *) = x
 (DoubleUnwrap * x) = x

tests/golden_tests/simplify_matches/flatten_with_terminal.bend

@@ -1,6 +1,6 @@
 # The flattened rule should only have 1 arg, for matching 'B'
-data A_t = (A b)
-data B_t = B
+type A_t = (A b)
+type B_t = B
 
 (Foo 0 (A_t/A B_t/B)) = B_t/B
 (Foo * *) = *

tests/golden_tests/simplify_matches/linearize_match_all.bend

@@ -1,5 +1,5 @@
 # Testing linearization in different situations
-data ConsList = (Cons h t) | Nil
+type ConsList = (Cons h t) | Nil
 
 # Auto linearized on strict mode
 A = @a @b @c switch a {

tests/golden_tests/simplify_matches/nested.bend

@@ -1,6 +1,6 @@
-data Foo = (CtrA a b) | (CtrB a)
-data Bar = (CtrB1 b) | (CtrB2 a b)
-data Baz = CtrC
+type Foo = (CtrA a b) | (CtrB a)
+type Bar = (CtrB1 b) | (CtrB2 a b)
+type Baz = CtrC
 
 (Rule (Foo/CtrA a (Bar/CtrB1 b))) = (a b)
 (Rule (Foo/CtrA a (Bar/CtrB2 (Baz/CtrC) b))) = (a b)

tests/golden_tests/simplify_matches/nested_0ary.bend

@@ -1,4 +1,4 @@
-data list = (Cons head tail) | Nil
+type list = (Cons head tail) | Nil
 
 Unpack cmp list/Nil = list/Nil
 Unpack cmp (list/Cons h list/Nil) = h

tests/snapshots/compile_file__just_data.bend.snap

@@ -6,4 +6,4 @@ input_file: tests/golden_tests/compile_file/just_data.bend
 In tests/golden_tests/compile_file/just_data.bend :
 - expected: datatype name
 - detected: end of input
- 1 | data 
+ 1 | type 

tests/snapshots/compile_file__missing_adt_eq.bend.snap

@@ -6,4 +6,4 @@ input_file: tests/golden_tests/compile_file/missing_adt_eq.bend
 In tests/golden_tests/compile_file/missing_adt_eq.bend :
 - expected: '='
 - detected: end of input
-  1 | data Adt 
+  1 | type Adt 

tests/snapshots/compile_file__missing_ctrs.bend.snap

@@ -6,4 +6,4 @@ input_file: tests/golden_tests/compile_file/missing_ctrs.bend
 In tests/golden_tests/compile_file/missing_ctrs.bend :
 - expected: datatype constructor name
 - detected: end of input
-  1 | data Adt =  
+  1 | type Adt =