Fix 'wrap' being considered a variable inside 'with'

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project does not currently adhere to a particular versioning scheme.
 - Expand references to functions generated by the `float_combinators` pass inside the main function. ([#642][gh-642])
 - Expand references inside constructors in the main function. ([#643][gh-643])
 - Fix readback when hvm net has `a{n}` or `x{n}` vars. ([#659][gh-659])
+- Fix `wrap` inside `with` being deferred applied like a variable. ([#664][gh-664])
 
 ### Added
 
@@ -23,6 +24,7 @@ and this project does not currently adhere to a particular versioning scheme.
 - Add error message when input file is not found. ([#513][gh-513])
 - Add `List/filter` and `String/{equals, filter}` builtins.
 - Add IO functions for loading dynamically linked libraries (`IO/DyLib/open`, `IO/DyLib/call`, `IO/DyLib/close`). ([#621][gh-621])
+- Add builtin functions `Tree/to_list`, `Tree/reverse`, `DiffList/concat` and `DiffList/wrap`. ([#662][gh-662])
 
 ### Changed
 
@@ -420,4 +422,6 @@ and this project does not currently adhere to a particular versioning scheme.
 [gh-648]: https://github.com/HigherOrderCO/Bend/issues/648
 [gh-657]: https://github.com/HigherOrderCO/Bend/issues/657
 [gh-659]: https://github.com/HigherOrderCO/Bend/pull/659
+[gh-662]: https://github.com/HigherOrderCO/Bend/pull/662
+[gh-664]: https://github.com/HigherOrderCO/Bend/issues/664
 [Unreleased]: https://github.com/HigherOrderCO/Bend/compare/0.2.36...HEAD

src/fun/check/unbound_vars.rs

@@ -38,8 +38,12 @@ impl Ctx<'_> {
 
 impl Term {
   /// Checks that all variables are bound.
-  /// Precondition: References have been resolved, implicit binds have been solved.
-
+  ///
+  /// Precondition: References have been resolved, implicit binds
+  /// have been solved.
+  ///
+  /// `check_unbound_vars` should be called once before this, since
+  /// the original names will be lost after.
   pub fn check_unbound_vars<'a>(
     &'a mut self,
     scope: &mut HashMap<&'a Name, u64>,
@@ -127,17 +131,17 @@ impl std::fmt::Display for UnboundVarErr {
         if var == desugar_bend::RECURSIVE_KW {
           write!(
             f,
-            "Unbound variable '{}'.\n    Note: '{}' is only a keyword inside the 'when' arm of a 'bend'.",
+            "Unbound name '{}'.\n    Note: '{}' is only a keyword inside the 'when' arm of a 'bend'.",
             var,
             desugar_bend::RECURSIVE_KW
           )
         } else if let Some((pre, suf)) = var.rsplit_once('-') {
           write!(
             f,
-            "Unbound variable '{var}'. If you wanted to subtract '{pre}' from '{suf}', you must separate it with spaces ('{pre} - {suf}') since '-' is a valid name character."
+            "Unbound name '{var}'. If you wanted to subtract '{pre}' from '{suf}', you must separate it with spaces ('{pre} - {suf}') since '-' is a valid name character."
           )
         } else {
-          write!(f, "Unbound variable '{var}'.")
+          write!(f, "Unbound name '{var}'.")
         }
       }
       UnboundVarErr::Global { var, declared, used } => match (declared, used) {

src/fun/parser.rs

@@ -759,6 +759,11 @@ impl<'a> TermParser<'a> {
         let typ = self.parse_name()?;
         self.consume("{")?;
         let bod = self.parse_term()?;
+        let bod = Term::Use {
+          nam: Some(Name::new("wrap")),
+          val: Box::new(Term::Var { nam: Name::new(format!("{typ}/wrap")) }),
+          nxt: Box::new(bod),
+        };
         self.consume("}")?;
         return Ok(Term::With { typ: Name::new(typ), bod: Box::new(bod) });
       }

src/fun/transform/desugar_use.rs

@@ -13,6 +13,8 @@ impl Book {
   ///
   /// // Transforms to:
   /// (λx x λx x λx x)
+  ///
+  /// Should only be used after `make_var_names_unique`.
   /// ```
   pub fn desugar_use(&mut self) {
     for def in self.defs.values_mut() {

src/fun/transform/desugar_with_blocks.rs

@@ -33,13 +33,7 @@ impl Term {
     maybe_grow(|| {
       if let Term::With { typ, bod } = self {
         bod.desugar_with_blocks(Some(typ), def_names)?;
-        let wrap_ref = Term::r#ref(&format!("{typ}/wrap"));
-        // let wrap_ref = if def_names.contains(&wrap_nam) {
-        //   Term::r#ref(&wrap_nam)
-        // } else {
-        //   return Err(format!("Could not find definition {wrap_nam} for type {typ}"));
-        // };
-        *self = Term::Use { nam: Some(Name::new("wrap")), val: Box::new(wrap_ref), nxt: std::mem::take(bod) };
+        *self = std::mem::take(bod);
       }
 
       if let Term::Ask { pat, val, nxt } = self {

src/fun/transform/fix_match_terms.rs

@@ -22,7 +22,7 @@ impl Ctx<'_> {
   ///
   /// Example:
   /// For the program
-  /// ```hvm
+  /// ```bend
   /// data MyList = (Cons h t) | Nil
   /// match x {
   ///   Cons: (A x.h x.t)
@@ -35,9 +35,9 @@ impl Ctx<'_> {
   /// * The bind `%matched-2` will be generated and stored in the switch term.
   /// * If either was missing one of the match cases (a number or a constructor), we'd get an error.
   /// * If either included one of the cases more than once (including wildcard patterns), we'd get a warning.
-  /// ```hvm
+  /// ```bend
   /// match x {
-  ///   Cons: (A x.h x.t)
+  ///   Cons x.h x.t: (A x.h x.t)
   ///   Nil: let %matched = (Foo y); switch %matched { 0: B; 1: C; _: D }
   /// }
   /// ```

src/fun/transform/unique_names.rs

@@ -9,6 +9,7 @@ use std::collections::HashMap;
 impl Book {
   /// Makes all variables in each definition have a new unique name.
   /// Skips unbound variables.
+  ///
   /// Precondition: Definition references have been resolved.
   pub fn make_var_names_unique(&mut self) {
     for def in self.defs.values_mut() {
@@ -32,7 +33,7 @@ pub struct UniqueNameGenerator {
 }
 
 impl UniqueNameGenerator {
-  // Recursively assign an id to each variable in the term, then convert each id into a unique name.
+  /// Recursively assign an id to each variable in the term, then convert each id into a unique name.
   pub fn unique_names_in_term(&mut self, term: &mut Term) {
     // Note: we can't use the children iterators here because we mutate the binds,
     // which are shared across multiple children.
@@ -189,14 +190,16 @@ impl UniqueNameGenerator {
     }
   }
 
-  fn use_var(&self, nam: &Name) -> Name {
+  fn use_var(&mut self, nam: &Name) -> Name {
     if let Some(vars) = self.name_map.get(nam) {
       let var_id = *vars.last().unwrap();
       Name::from(var_id)
     } else {
       // Skip unbound variables.
       // With this, we can use this function before checking for unbound vars.
-      nam.clone()
+      let nam = Name::from(self.name_count);
+      self.name_count += 1;
+      nam
     }
   }
 }

src/imp/parser.rs

@@ -900,6 +900,11 @@ impl<'a> PyParser<'a> {
 
     self.consume_indent_exactly(*indent)?;
     let (bod, nxt_indent) = self.parse_statement(indent)?;
+    let bod = Stmt::Use {
+      nam: Name::new("wrap"),
+      val: Box::new(Expr::Var { nam: Name::new(format!("{typ}/wrap")) }),
+      nxt: Box::new(bod),
+    };
     indent.exit_level();
 
     if nxt_indent == *indent {

src/lib.rs

@@ -113,10 +113,13 @@ pub fn desugar_book(
 
   ctx.desugar_bend()?;
   ctx.desugar_fold()?;
-  ctx.desugar_with_blocks()?;
 
   ctx.check_unbound_vars()?;
 
+  ctx.book.make_var_names_unique();
+  ctx.book.desugar_use();
+  ctx.desugar_with_blocks()?;
+
   // Auto match linearization
   ctx.book.make_var_names_unique();
   ctx.book.desugar_use();

tests/golden_tests/compile_file/ask_outside_do.bend

@@ -1 +1 @@
-main = ask x = (Result/Ok x); x
+main = ask x = (Result/Ok 0); x

tests/golden_tests/compile_file_o_all/cyclic_dup.bend

@@ -1 +1 @@
-main = let {x1 x2} = y1; let {y1 y2} = x1; (x2 y2)
+main = let {$x1 x2} = $y1; let {$y1 y2} = $x1; (x2 y2)

tests/golden_tests/desugar_file/bind_syntax.bend

@@ -1,6 +1,8 @@
 Result/bind (Result/Ok val) f = ((undefer f) val)
 Result/bind err _ = err
 
+Result/wrap x = (Result/Ok x)
+
 safe_div a b = switch b {
   0: (Result/Err "Div by 0")
   _: (Result/Ok (/ a b))

tests/golden_tests/run_file/do_block_mixed.bend

@@ -4,6 +4,8 @@ Result/bind r nxt = match r {
   Result/Err: r
 }
 
+Result/wrap x = (Result/Ok x)
+
 main = with Result {
   let x = 1
   let y = (Result/Ok x)

tests/golden_tests/run_file/recursive_bind.bend

@@ -1,6 +1,8 @@
 Result/bind (Result/Ok val) f = ((undefer f) val)
 Result/bind err _ = err
 
+Result/wrap x = (Result/Ok x)
+
 Bar x = (Result/Err 0)
 
 Foo x y = with Result {

tests/golden_tests/run_file/strict_monad_fn.bend

@@ -3,6 +3,9 @@ Result/bind = @val @nxt match val {
   Result/Ok: ((undefer nxt) val.val)
   Result/Err: (Result/Err val.val)
 }
+
+Result/wrap x = (Result/Ok x)
+
 Result/foo x y = 
   with Result {
     ask a = (Result/Ok x)

tests/snapshots/cli__warn_and_err.bend.snap

@@ -8,4 +8,4 @@ input_file: tests/golden_tests/cli/warn_and_err.bend
 
 Errors:
 In definition 'Main':
-  Unbound variable 'a'.
+  Unbound name 'a'.

tests/snapshots/compile_file__ask_outside_do.bend.snap

@@ -4,4 +4,4 @@ input_file: tests/golden_tests/compile_file/ask_outside_do.bend
 ---
 Errors:
 In definition 'main':
-  Monadic bind operation 'x <- ...' used outside of a `do` block.
+  Monadic bind operation 'a <- ...' used outside of a `do` block.

tests/snapshots/compile_file__unbound_var.bend.snap

@@ -4,4 +4,4 @@ input_file: tests/golden_tests/compile_file/unbound_var.bend
 ---
 Errors:
 In definition 'main':
-  Unbound variable 'a'.
+  Unbound name 'a'.

tests/snapshots/compile_file__unbound_var_scope.bend.snap

@@ -4,4 +4,4 @@ input_file: tests/golden_tests/compile_file/unbound_var_scope.bend
 ---
 Errors:
 In definition 'main':
-  Unbound variable 'b'.
+  Unbound name 'b'.

tests/snapshots/compile_file__unbound_with_tup_pattern.bend.snap

@@ -4,4 +4,4 @@ input_file: tests/golden_tests/compile_file/unbound_with_tup_pattern.bend
 ---
 Errors:
 In definition 'Foo':
-  Unbound variable 'a'.
+  Unbound name 'a'.

tests/snapshots/compile_file__warn_and_err.bend.snap

@@ -8,4 +8,4 @@ input_file: tests/golden_tests/compile_file/warn_and_err.bend
 
 Errors:
 In definition 'Main':
-  Unbound variable 'a'.
+  Unbound name 'a'.

tests/snapshots/compile_file_o_all__bad_parens_making_erased_let.bend.snap

@@ -4,5 +4,5 @@ input_file: tests/golden_tests/compile_file_o_all/bad_parens_making_erased_let.b
 ---
 Errors:
 In definition 'main':
-  Unbound variable 'two'.
-  Unbound variable 'qua'.
+  Unbound name 'two'.
+  Unbound name 'qua'.

tests/snapshots/compile_file_o_all__cyclic_dup.bend.snap

@@ -3,5 +3,5 @@ source: tests/golden_tests.rs
 input_file: tests/golden_tests/compile_file_o_all/cyclic_dup.bend
 ---
 Errors:
-In definition 'main':
-  Unbound variable 'y1'.
+In compiled inet 'main':
+  Found term that compiles into an inet with a vicious cycle

tests/snapshots/desugar_file__ask_branch.bend.snap

@@ -10,7 +10,7 @@ input_file: tests/golden_tests/desugar_file/ask_branch.bend
 
 (IO/bind) = λa λb (a IO/bind__C2 b)
 
-(main) = (IO/bind (Bool/T λa switch a { 0: (IO/wrap 0); _: λ* (IO/wrap 0); }) λb (b λc λd (c d) IO/wrap))
+(main) = (IO/bind (Bool/T λa switch a { 0: (IO/wrap 0); _: λ* (IO/wrap 0); }) λb (b λc (IO/wrap c)))
 
 (IO/Done) = λa λb λc (c IO/Done/tag a b)
 

tests/snapshots/desugar_file__bind_syntax.bend.snap

@@ -6,6 +6,8 @@ input_file: tests/golden_tests/desugar_file/bind_syntax.bend
 
 (Result/bind) = λa λb (a Result/bind__C2 b)
 
+(Result/wrap) = λa (Result/Ok a)
+
 (safe_div) = λa λb (switch b { 0: λ* (Result/Err (String/Cons 68 (String/Cons 105 (String/Cons 118 (String/Cons 32 (String/Cons 98 (String/Cons 121 (String/Cons 32 (String/Cons 48 String/Nil))))))))); _: safe_div__C0; } a)
 
 (safe_rem) = λa λb (switch b { 0: λ* (Result/Err (String/Cons 77 (String/Cons 111 (String/Cons 100 (String/Cons 32 (String/Cons 98 (String/Cons 121 (String/Cons 32 (String/Cons 48 String/Nil))))))))); _: safe_rem__C0; } a)

tests/snapshots/parse_file__imp_program.bend.snap

@@ -8,6 +8,10 @@ input_file: tests/golden_tests/parse_file/imp_program.bend
 
 (Map/set) = λ%arg0 λ%arg1 λ%arg2 use value = %arg2; use key = %arg1; use map = %arg0; match map = map { Map/Node: switch _ = (== 0 key) { 0: switch _ = (% key 2) { 0: (Map/Node map.value (Map/set map.left (/ key 2) value) map.right); _ _-1: (Map/Node map.value map.left (Map/set map.right (/ key 2) value)); }; _ _-1: (Map/Node value map.left map.right); }; Map/Leaf: switch _ = (== 0 key) { 0: switch _ = (% key 2) { 0: (Map/Node * (Map/set Map/Leaf (/ key 2) value) Map/Leaf); _ _-1: (Map/Node * Map/Leaf (Map/set Map/Leaf (/ key 2) value)); }; _ _-1: (Map/Node value Map/Leaf Map/Leaf); }; }
 
+(IO/MAGIC) = (13683217, 16719857)
+
+(IO/wrap) = λ%arg0 use x = %arg0; (IO/Done IO/MAGIC x)
+
 (symbols) = let x = (Map/set (Map/set Map/empty 49 5) 2 3); let x = (Map/set x 49 2); let x = (Map/set x 2 3); let (map/get%0, x) = (Map/get x 49); (+ map/get%0 8293490)
 
 (mk_point) = (Point/Point 1 2)
@@ -36,7 +40,7 @@ input_file: tests/golden_tests/parse_file/imp_program.bend
 
 (sup) = let x = {(List/Cons 1 (List/Cons 2 List/Nil)) (List/Cons 3 (List/Cons 4 (List/Cons 5 (List/Cons 6 List/Nil))))}; x
 
-(main) = with IO { ask x = IO.read; x }
+(main) = with IO { use wrap = IO/wrap; ask x = IO.read; x }
 
 (List/Nil) = λ%x (%x List/Nil/tag)
 
@@ -46,6 +50,8 @@ input_file: tests/golden_tests/parse_file/imp_program.bend
 
 (Map/Leaf) = λ%x (%x Map/Leaf/tag)
 
+(IO/Done) = λmagic λexpr λ%x (%x IO/Done/tag magic expr)
+
 (Point/Point) = λx λy λ%x (%x Point/Point/tag x y)
 
 (Bool/True) = λ%x (%x Bool/True/tag)
@@ -60,6 +66,8 @@ input_file: tests/golden_tests/parse_file/imp_program.bend
 
 (Map/Leaf/tag) = 1
 
+(IO/Done/tag) = 0
+
 (Point/Point/tag) = 0
 
 (Bool/True/tag) = 0

tests/snapshots/run_file__unbound_wrap.bend.snap

@@ -4,4 +4,4 @@ input_file: tests/golden_tests/run_file/unbound_wrap.bend
 ---
 Errors:
 In definition 'main':
-  Reference to undefined function 'Maybe/wrap'
+  Unbound name 'Maybe/wrap'.