Support '??' syntax for optional record fields

crates/compiler/builtins/roc/List.roc

@@ -871,7 +871,7 @@ mapWithIndexHelp = \src, dest, func, index, length ->
 ## All of these options are compatible with the others. For example, you can use `At` or `After`
 ## with `start` regardless of what `end` and `step` are set to.
 range : _
-range = \{ start, end, step ? 0 } ->
+range = \{ start, end, step ?? 0 } ->
     { calcNext, stepIsPositive } =
         if step == 0 then
             when T start end is

crates/compiler/builtins/roc/Num.roc

@@ -618,8 +618,8 @@ isGte : Num a, Num a -> Bool
 ##
 ## If either argument is [*NaN*](Num.isNaN), returns `Bool.false` no matter what. (*NaN*
 ## is [defined to be unordered](https://en.wikipedia.org/wiki/NaN#Comparison_with_NaN).)
-isApproxEq : Frac a, Frac a, { rtol ? Frac a, atol ? Frac a } -> Bool
+isApproxEq : Frac a, Frac a, { rtol ?? Frac a, atol ?? Frac a } -> Bool
-isApproxEq = \x, y, { rtol ? 0.00001, atol ? 0.00000001 } ->
+isApproxEq = \x, y, { rtol ?? 0.00001, atol ?? 0.00000001 } ->
     eq = x <= y && x >= y
     meetsTolerance = Num.absDiff x y <= Num.max atol (rtol * Num.max (Num.abs x) (Num.abs y))
     eq || meetsTolerance

crates/compiler/fmt/src/annotation.rs

@@ -386,7 +386,7 @@ impl<'a> Nodify<'a> for AssignedField<'a, TypeAnnotation<'a>> {
                 assigned_field_value_to_node(n.into_bump_str(), arena, sp, &value.value, ":", flags)
             }
             AssignedField::OptionalValue(name, sp, value) => {
-                assigned_field_value_to_node(name.value, arena, sp, &value.value, "?", flags)
+                assigned_field_value_to_node(name.value, arena, sp, &value.value, "??", flags)
             }
             AssignedField::LabelOnly(name) => NodeInfo {
                 before: &[],
@@ -512,7 +512,7 @@ fn format_assigned_field_help<T>(
 
             buf.spaces(separator_spaces);
             buf.indent(indent);
-            buf.push('?');
+            buf.push_str("??");
             buf.spaces(1);
             ann.value.format(buf, indent);
         }

crates/compiler/fmt/src/expr.rs

@@ -701,16 +701,8 @@ fn fmt_apply(
     if !expr.before.is_empty() {
         format_spaces(buf, expr.before, Newlines::Yes, indent);
     }
-    expr.item.format_with_options(
+    expr.item
-        buf,
+        .format_with_options(buf, Parens::InApply, Newlines::Yes, indent);
-        if use_commas_and_parens {
-            Parens::NotNeeded
-        } else {
-            Parens::InApply
-        },
-        Newlines::Yes,
-        indent,
-    );
 
     if use_commas_and_parens {
         buf.push('(');

crates/compiler/fmt/src/pattern.rs

@@ -268,7 +268,7 @@ fn fmt_pattern_only(
         Pattern::OptionalField(name, loc_pattern) => {
             buf.indent(indent);
             snakify_camel_ident(buf, name);
-            buf.push_str(" ?");
+            buf.push_str(" ??");
             buf.spaces(1);
             loc_pattern.format(buf, indent);
         }

crates/compiler/load/tests/test_reporting.rs

@@ -4538,8 +4538,8 @@ mod test_reporting {
     4│      f : { foo  bar }
                        ^
 
-    I was expecting to see a colon, question mark, comma or closing curly
+    I was expecting to see a colon, two question marks (??), comma or
-    brace.
+    closing curly brace.
     "
     );
 

crates/compiler/parse/src/expr.rs

@@ -2082,6 +2082,7 @@ pub fn merge_spaces<'a>(
 /// If the given Expr would parse the same way as a valid Pattern, convert it.
 /// Example: (foo) could be either an Expr::Var("foo") or Pattern::Identifier("foo")
 fn expr_to_pattern_help<'a>(arena: &'a Bump, expr: &Expr<'a>) -> Result<Pattern<'a>, ()> {
+    println!("expr_to_pattern_help");
     let mut expr = expr.extract_spaces();
 
     while let Expr::ParensAround(loc_expr) = &expr.item {
@@ -3587,7 +3588,10 @@ pub fn record_field<'a>() -> impl Parser<'a, RecordField<'a>, ERecord<'a>> {
                     optional(either(
                         and(byte(b':', ERecord::Colon), record_field_expr()),
                         and(
-                            byte(b'?', ERecord::QuestionMark),
+                            and(
+                                byte(b'?', ERecord::QuestionMark),
+                                optional(byte(b'?', ERecord::QuestionMark)),
+                            ),
                             spaces_before(specialize_err_ref(ERecord::Expr, loc_expr(true))),
                         ),
                     )),

crates/compiler/parse/src/pattern.rs

@@ -5,7 +5,7 @@ use crate::blankspace::{space0_before_optional_after, space0_e, spaces, spaces_b
 use crate::ident::{lowercase_ident, parse_ident, Accessor, Ident};
 use crate::keyword;
 use crate::parser::{
-    self, backtrackable, byte, collection_trailing_sep_e, fail_when, loc, map, map_with_arena,
+    self, and, backtrackable, byte, collection_trailing_sep_e, fail_when, loc, map, map_with_arena,
     optional, skip_first, skip_second, specialize_err, specialize_err_ref, then, three_bytes,
     two_bytes, zero_or_more, EPattern, PInParens, PList, PRecord, Parser,
 };
@@ -551,7 +551,10 @@ fn record_pattern_field<'a>() -> impl Parser<'a, Loc<Pattern<'a>>, PRecord<'a>>
         // (This is true in both literals and types.)
         let (_, opt_loc_val, state) = optional(either(
             byte(b':', PRecord::Colon),
-            byte(b'?', PRecord::Optional),
+            and(
+                byte(b'?', PRecord::Optional),
+                optional(byte(b'?', PRecord::Optional)),
+            ),
         ))
         .parse(arena, state, min_indent)?;
 

crates/compiler/parse/src/type_annotation.rs

@@ -588,7 +588,10 @@ fn record_type_field<'a>() -> impl Parser<'a, AssignedField<'a, TypeAnnotation<'
         // (This is true in both literals and types.)
         let (_, opt_loc_val, state) = optional(either(
             byte(b':', ETypeRecord::Colon),
-            byte(b'?', ETypeRecord::Optional),
+            and(
+                byte(b'?', ETypeRecord::Optional),
+                optional(byte(b'?', ETypeRecord::Optional)),
+            ),
         ))
         .parse(arena, state, min_indent)?;
 

crates/compiler/test_syntax/src/minimize.rs

@@ -102,10 +102,7 @@ fn round_trip_once(input: Input<'_>, options: Options) -> Option<String> {
     let arena = Bump::new();
 
     let actual = match input.parse_in(&arena) {
-        Ok(a) => {
+        Ok(a) => a,
-            println!("actual {a:#?}");
-            a
-        }
         Err(e) => {
             if options.minimize_initial_parse_error {
                 return Some(format!("Initial parse failed: {:?}", e.normalize(&arena)));

crates/compiler/test_syntax/tests/snapshots/pass/closure_complex_pattern_indent_issue.expr.formatted.roc

@@ -1,3 +1,3 @@
-\I { p ? Y
+\I { p ?? Y
     Y } [] ->
         K # (

crates/compiler/test_syntax/tests/snapshots/pass/if_in_record_field_opt_pat.expr.formatted.roc

@@ -1,5 +1,5 @@
 O
-    { p ? if
+    { p ?? if
         a
     then
         A

crates/compiler/test_syntax/tests/snapshots/pass/module_with_optional_param.header.formatted.roc

@@ -1 +1 @@
-module { x, y ? 0 } -> [menu]
+module { x, y ?? 0 } -> [menu]

crates/compiler/test_syntax/tests/snapshots/pass/multiline_str_opt_field.expr.formatted.roc

@@ -1,5 +1,5 @@
 {
-    l?
+    l??
     """
     """,
 }

crates/compiler/test_syntax/tests/snapshots/pass/newline_after_opt_field.expr.formatted.roc

@@ -1,3 +1,3 @@
 {
-    i? p,
+    i?? p,
 }

crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_pat.expr.formatted.roc

@@ -1,2 +1,2 @@
-{ i ? Y } = p
+{ i ?? Y } = p
 Q

crates/compiler/test_syntax/tests/snapshots/pass/opt_field_newline_in_ty.expr.formatted.roc

@@ -1,5 +1,5 @@
 0 : {
     i
-    ? d,
+    ?? d,
 }
 O

crates/compiler/test_syntax/tests/snapshots/pass/opt_record_field_pat_assign.expr.formatted.roc

@@ -1,4 +1,4 @@
-{ e ? f
+{ e ?? f
     4 } = f
         e
 r

crates/compiler/test_syntax/tests/snapshots/pass/pattern_opt_field_bonanza.expr.formatted.roc

@@ -1,8 +1,8 @@
 M
-    { s ? s
+    { s ?? s
         { J &
         } }
-    { s ? s
+    { s ?? s
         { J &
         } } : p
 y

crates/compiler/test_syntax/tests/test_fmt.rs

@@ -2497,13 +2497,13 @@ mod test_fmt {
         expr_formats_to(
             indoc!(
                 r"
-                f : { a ?Str }
+                f : { a ??Str }
 
                 f"
             ),
             indoc!(
                 r"
-                f : { a ? Str }
+                f : { a ?? Str }
 
                 f"
             ),
@@ -2513,7 +2513,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    a ?Str,
+                    a ??Str,
                 }
 
                 f"
@@ -2521,7 +2521,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    a ? Str,
+                    a ?? Str,
                 }
 
                 f"
@@ -2743,7 +2743,7 @@ mod test_fmt {
                 r"
                 f :
                     {
-                        someField ? Int * # comment 1
+                        someField ?? Int * # comment 1
                         ,
                         # comment 2
                     }
@@ -2753,7 +2753,7 @@ mod test_fmt {
             indoc!(
                 r"
                 f : {
-                    some_field ? Int *, # comment 1
+                    some_field ?? Int *, # comment 1
                     # comment 2
                 }
 

crates/reporting/src/error/parse.rs

@@ -2889,7 +2889,7 @@ fn to_trecord_report<'a>(
                         alloc.region_with_subregion(lines.convert_region(surroundings), region, severity),
                         alloc.concat([
                             alloc.reflow(
-                                r"I was expecting to see a colon, question mark, comma or closing curly brace.",
+                                r"I was expecting to see a colon, two question marks (??), comma or closing curly brace.",
                             ),
                         ]),
                     ]);