more backtracking

compiler/gen/tests/gen_num.rs

@@ -51,6 +51,9 @@ mod gen_num {
         assert_evals_to!(
             indoc!(
                 r#"
+                app "test" provides [ main ] to "./platform"
+
+                main =
                     i : I64
                     i = 64
 
@@ -446,24 +449,6 @@ mod gen_num {
             -1,
             i64
         );
-
-        assert_evals_to!(
-            indoc!(
-                r#"
-                    limitedNegate = \num ->
-                        if num == 1 then
-                            -1
-                        else if num == -1 then
-                            1
-                        else
-                            num
-
-                    limitedNegate 1
-                "#
-            ),
-            -1,
-            i64
-        );
     }
 
     #[test]

compiler/load/src/file.rs

@@ -3396,9 +3396,7 @@ fn parse<'a>(arena: &'a Bump, header: ModuleHeader<'a>) -> Result<Msg<'a>, Loadi
                 ),
                 _ => panic!(
                     "Parser Error\nmodule: {:?}\nattempting: {:?}\n(line, col): {:?}\n",
-                    header.module_id,
+                    header.module_id, fail.attempting, &state
-                    fail.attempting,
-                    (state.line, state.column)
                 ),
             }
         }

compiler/parse/src/expr.rs

@@ -174,8 +174,9 @@ fn loc_parse_expr_body_without_operators<'a>(
 pub fn unary_op<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>> {
     one_of!(
         map_with_arena!(
+            // must backtrack to distinguish `!x` from `!= y`
             and!(
-                loc!(ascii_char(b'!')),
+                loc!(backtrackable(ascii_char(b'!'))),
                 loc!(move |arena, state| parse_expr(min_indent, arena, state))
             ),
             |arena: &'a Bump, (loc_op, loc_expr): (Located<()>, Located<Expr<'a>>)| {
@@ -208,9 +209,7 @@ fn parse_expr<'a>(min_indent: u16, arena: &'a Bump, state: State<'a>) -> ParseRe
             optional(and!(
                 // and!(space0(min_indent), loc!(binop())),
                 move |arena, state| {
-                    dbg!("... -----> starting here");
                     let (_, spaces, state) = space0(min_indent).parse(arena, state)?;
-                    dbg!("got here");
                     let (_, op, state) = loc!(binop()).parse(arena, state)?;
 
                     Ok((MadeProgress, (spaces, op), state))
@@ -225,7 +224,7 @@ fn parse_expr<'a>(min_indent: u16, arena: &'a Bump, state: State<'a>) -> ParseRe
                 )
             ))
         ),
-        |arena, (loc_expr1, opt_operator)| match dbg!(opt_operator) {
+        |arena, (loc_expr1, opt_operator)| match opt_operator {
             Some(((spaces_before_op, loc_op), loc_expr2)) => {
                 let loc_expr1 = if spaces_before_op.is_empty() {
                     loc_expr1
@@ -583,10 +582,16 @@ fn spaces_then_comment_or_newline<'a>() -> impl Parser<'a, Option<&'a str>> {
 type Body<'a> = (Located<Pattern<'a>>, Located<Expr<'a>>);
 
 fn body<'a>(min_indent: u16) -> impl Parser<'a, Body<'a>> {
-    dbg!("we get here?");
     let indented_more = min_indent + 1;
     let result = and!(
-        pattern(min_indent),
+        // this backtrackable is required for the case
+        //
+        // i = 64
+        //
+        // i
+        //
+        // so the final i is not considered the start of a def
+        backtrackable(pattern(min_indent)),
         skip_first!(
             equals_for_def(),
             // Spaces after the '=' (at a normal indentation level) and then the expr.
@@ -1570,14 +1575,11 @@ fn unary_negate_function_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<Exp
     then(
         // Spaces, then '-', then *not* more spaces.
         not_followed_by(
-            and!(
+            either!(
-                backtrackable(space1(min_indent)),
+                // Try to parse a number literal *before* trying to parse unary negate,
-                either!(
+                // because otherwise (foo -1) will parse as (foo (Num.neg 1))
-                    // Try to parse a number literal *before* trying to parse unary negate,
+                loc!(number_literal()),
-                    // because otherwise (foo -1) will parse as (foo (Num.neg 1))
+                loc!(ascii_char(b'-'))
-                    loc!(number_literal()),
-                    loc!(ascii_char(b'-'))
-                )
             ),
             one_of!(
                 ascii_char(b' '),
@@ -1586,7 +1588,7 @@ fn unary_negate_function_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<Exp
                 ascii_char(b'>')
             ),
         ),
-        move |arena, state, progress, (spaces, num_or_minus_char)| {
+        move |arena, state, progress, num_or_minus_char| {
             debug_assert_eq!(progress, MadeProgress);
 
             match num_or_minus_char {
@@ -1616,12 +1618,7 @@ fn unary_negate_function_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<Exp
                         value,
                     };
 
-                    // spaces can be empy if it's all space characters (no newlines or comments).
+                    let value = loc_expr.value;
-                    let value = if spaces.is_empty() {
-                        loc_expr.value
-                    } else {
-                        Expr::SpaceBefore(arena.alloc(loc_expr.value), spaces)
-                    };
 
                     Ok((
                         MadeProgress,
@@ -1638,13 +1635,27 @@ fn unary_negate_function_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<Exp
 }
 
 fn loc_function_args<'a>(min_indent: u16) -> impl Parser<'a, Vec<'a, Located<Expr<'a>>>> {
-    move |a, s| {
+    one_or_more!(move |arena: &'a Bump, s| {
-        dbg!((one_or_more!(one_of!(
+        map!(
-            unary_negate_function_arg(min_indent),
+            and!(
-            space1_before(loc_function_arg(min_indent), min_indent)
+                backtrackable(space1(min_indent)),
-        )))
+                one_of!(
-        .parse(a, s))
+                    unary_negate_function_arg(min_indent),
-    }
+                    loc_function_arg(min_indent)
+                )
+            ),
+            |(spaces, loc_expr): (&'a [_], Located<Expr<'a>>)| {
+                if spaces.is_empty() {
+                    loc_expr
+                } else {
+                    arena
+                        .alloc(loc_expr.value)
+                        .with_spaces_before(spaces, loc_expr.region)
+                }
+            }
+        )
+        .parse(arena, s)
+    })
 }
 
 /// When we parse an ident like `foo ` it could be any of these:
@@ -1674,8 +1685,6 @@ fn ident_etc<'a>(min_indent: u16) -> impl Parser<'a, Expr<'a>> {
         move |arena, state, progress, (loc_ident, opt_extras)| {
             debug_assert_eq!(progress, MadeProgress);
 
-            dbg!("parsed the ident", &opt_extras);
-
             // This appears to be a var, keyword, or function application.
             match opt_extras {
                 (Some(loc_args), Some((_spaces_before_equals, Either::First(_equals_indent)))) => {

compiler/parse/src/module.rs

@@ -298,7 +298,7 @@ pub fn platform_header<'a>() -> impl Parser<'a, PlatformHeader<'a>> {
 pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>> {
     move |a: &'a Bump, s: State<'a>| {
         // this parses just the defs
-        let defs = zero_or_more!(space0_around(loc(debug!(def(0))), 0));
+        let defs = zero_or_more!(space0_around(loc(def(0)), 0));
 
         // let result = skip_second!(defs, end_of_file()).parse(a, s);
         let result = defs.parse(a, s);
@@ -322,8 +322,8 @@ fn provides_to<'a>() -> impl Parser<'a, ProvidesTo<'a>> {
     map!(
         and!(
             and!(
-                skip_second!(debug!(backtrackable(space1(1))), ascii_string("provides")),
+                skip_second!(backtrackable(space1(1)), ascii_string("provides")),
-                debug!(space1(1))
+                space1(1)
             ),
             and!(
                 collection!(

compiler/parse/src/parser.rs

@@ -792,7 +792,7 @@ where
                     }
                 }
             }
-            Err((element_progress, fail, new_state)) => match dbg!(element_progress) {
+            Err((element_progress, fail, new_state)) => match element_progress {
                 MadeProgress => {
                     return Err((
                         MadeProgress,
@@ -1058,16 +1058,12 @@ macro_rules! collection {
                 // We could change the AST to add extra storage specifically to
                 // support empty literals containing newlines or comments, but this
                 // does not seem worth even the tiniest regression in compiler performance.
-                {
+                zero_or_more!($crate::parser::ascii_char(b' ')),
-                    dbg!("we are here? ");
-                    |a, s| dbg!(zero_or_more!($crate::parser::ascii_char(b' ')).parse(a, s))
-                },
                 skip_second!(
-                    move |a, s| dbg!($crate::parser::sep_by0(
+                    $crate::parser::sep_by0(
                         $delimiter,
                         $crate::blankspace::space0_around($elem, $min_indent)
-                    )
+                    ),
-                    .parse(a, s)),
                     $closing_brace
                 )
             )
@@ -1260,8 +1256,6 @@ macro_rules! one_or_more {
         move |arena, state: State<'a>| {
             use bumpalo::collections::Vec;
 
-            dbg!(state.bytes);
-
             match $parser.parse(arena, state) {
                 Ok((_, first_output, next_state)) => {
                     let mut state = next_state;
@@ -1282,8 +1276,7 @@ macro_rules! one_or_more {
                     }
                 }
                 Err((progress, _, new_state)) => {
-                    dbg!(new_state.bytes);
+                    debug_assert_eq!(progress, NoProgress, "{:?}", &new_state);
-                    debug_assert_eq!(progress, NoProgress);
                     Err($crate::parser::unexpected_eof(
                         0,
                         new_state.attempting,

compiler/parse/src/type_annotation.rs

@@ -61,14 +61,13 @@ pub fn term<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotation<'a>>>
                 loc!(parse_type_variable)
             ),
             |a, s| {
-                dbg!("term state", &s);
                 optional(
                     // Inline type annotation, e.g. [ Nil, Cons a (List a) ] as List a
                     and!(
                         space1(min_indent),
                         skip_first!(
                             crate::parser::keyword(keyword::AS, min_indent),
-                            |a, s| dbg!(space1_before(term(min_indent), min_indent).parse(a, s))
+                            space1_before(term(min_indent), min_indent)
                         )
                     ),
                 )
@@ -125,7 +124,7 @@ fn loc_applied_arg<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotatio
 }
 
 fn loc_applied_args<'a>(min_indent: u16) -> impl Parser<'a, Vec<'a, Located<TypeAnnotation<'a>>>> {
-    zero_or_more!(move |arena, state| dbg!(loc_applied_arg(min_indent).parse(arena, state)))
+    zero_or_more!(loc_applied_arg(min_indent))
 }
 
 #[inline(always)]
@@ -220,7 +219,6 @@ fn applied_type<'a>(min_indent: u16) -> impl Parser<'a, TypeAnnotation<'a>> {
 }
 
 fn expression<'a>(min_indent: u16) -> impl Parser<'a, Located<TypeAnnotation<'a>>> {
-    dbg!("parsing type ig");
     use crate::blankspace::space0;
     move |arena, state: State<'a>| {
         let (p1, first, state) = space0_before(term(min_indent), min_indent).parse(arena, state)?;

compiler/parse/tests/test_parse.rs

@@ -1803,7 +1803,7 @@ mod test_parse {
             indoc!(
                 r#"
                 foo : Foo.Bar.Baz x y as Blah a b
-        
+
                 42
                 "#
             ),
@@ -1839,7 +1839,7 @@ mod test_parse {
             indoc!(
                 r#"
                 Blah a b : Foo.Bar.Baz x y
- 
+
                 42
                 "#
             ),
@@ -2773,6 +2773,52 @@ mod test_parse {
         assert_eq!(Ok(expected), actual);
     }
 
+    #[test]
+    fn module_def_newline() {
+        use roc_parse::ast::Def::*;
+
+        let arena = Bump::new();
+
+        let src = indoc!(
+            r#"
+                main =
+                    i = 64
+
+                    i
+            "#
+        );
+
+        let actual = module_defs()
+            .parse(&arena, State::new(src.as_bytes(), Attempting::Module))
+            .map(|tuple| tuple.1);
+
+        assert!(actual.is_ok());
+    }
+
+    #[test]
+    fn nested_def_annotation() {
+        use roc_parse::ast::Def::*;
+
+        let arena = Bump::new();
+
+        let src = indoc!(
+            r#"
+            main =
+                wrappedNotEq : a, a -> Bool
+                wrappedNotEq = \num1, num2 ->
+                    num1 != num2
+
+                wrappedNotEq 2 3
+            "#
+        );
+
+        let actual = module_defs()
+            .parse(&arena, State::new(src.as_bytes(), Attempting::Module))
+            .map(|tuple| tuple.1);
+
+        assert!(actual.is_ok());
+    }
+
     #[test]
     fn newline_after_equals() {
         // Regression test for https://github.com/rtfeldman/roc/issues/51