Allow trailing comments in imports decl

compiler/fmt/src/module.rs

@@ -1,6 +1,6 @@
 use crate::spaces::{fmt_spaces, INDENT};
 use bumpalo::collections::{String, Vec};
-use roc_parse::ast::Module;
+use roc_parse::ast::{Collection, Module};
 use roc_parse::header::{AppHeader, ExposesEntry, ImportsEntry, InterfaceHeader, PlatformHeader};
 use roc_region::all::Located;
 
@@ -64,7 +64,7 @@ pub fn fmt_interface_header<'a>(buf: &mut String<'a>, header: &'a InterfaceHeade
         fmt_spaces(buf, header.after_imports.iter(), indent);
     }
 
-    fmt_imports(buf, &header.imports, indent);
+    fmt_imports(buf, header.imports, indent);
 }
 
 pub fn fmt_app_header<'a>(buf: &mut String<'a>, header: &'a AppHeader<'a>) {
@@ -76,7 +76,7 @@ pub fn fmt_app_header<'a>(buf: &mut String<'a>, header: &'a AppHeader<'a>) {
     buf.push_str("imports");
 
     fmt_spaces(buf, header.before_imports.iter(), indent);
-    fmt_imports(buf, &header.imports, indent);
+    fmt_imports(buf, header.imports, indent);
     fmt_spaces(buf, header.after_imports.iter(), indent);
 }
 
@@ -86,7 +86,7 @@ pub fn fmt_platform_header<'a>(_buf: &mut String<'a>, _header: &'a PlatformHeade
 
 fn fmt_imports<'a>(
     buf: &mut String<'a>,
-    loc_entries: &'a Vec<'a, Located<ImportsEntry<'a>>>,
+    loc_entries: Collection<'a, Located<ImportsEntry<'a>>>,
     indent: u16,
 ) {
     buf.push('[');

compiler/load/src/file.rs

@@ -2609,7 +2609,7 @@ fn parse_header<'a>(
                 header_src,
                 packages: &[],
                 exposes: header.exposes.into_bump_slice(),
-                imports: header.imports.into_bump_slice(),
+                imports: header.imports.items,
                 to_platform: None,
             };
 
@@ -2643,7 +2643,7 @@ fn parse_header<'a>(
                 header_src,
                 packages,
                 exposes: header.provides.into_bump_slice(),
-                imports: header.imports.into_bump_slice(),
+                imports: header.imports.items,
                 to_platform: Some(header.to.value.clone()),
             };
 
@@ -3421,7 +3421,7 @@ fn fabricate_pkg_config_module<'a>(
         packages: &[],
         provides,
         requires: arena.alloc([header.requires.signature.clone()]),
-        imports: header.imports.clone().into_bump_slice(),
+        imports: header.imports.items,
     };
 
     send_header_two(

compiler/parse/src/header.rs

@@ -38,7 +38,7 @@ pub enum PackageOrPath<'a> {
     Path(StrLiteral<'a>),
 }
 
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
 pub struct ModuleName<'a>(&'a str);
 
 impl<'a> From<ModuleName<'a>> for &'a str {
@@ -61,7 +61,7 @@ impl<'a> ModuleName<'a> {
 pub struct InterfaceHeader<'a> {
     pub name: Loc<ModuleName<'a>>,
     pub exposes: Vec<'a, Loc<ExposesEntry<'a, &'a str>>>,
-    pub imports: Vec<'a, Loc<ImportsEntry<'a>>>,
+    pub imports: Collection<'a, Loc<ImportsEntry<'a>>>,
 
     // Potential comments and newlines - these will typically all be empty.
     pub before_header: &'a [CommentOrNewline<'a>],
@@ -82,7 +82,7 @@ pub enum To<'a> {
 pub struct AppHeader<'a> {
     pub name: Loc<StrLiteral<'a>>,
     pub packages: Collection<'a, Loc<PackageEntry<'a>>>,
-    pub imports: Vec<'a, Loc<ImportsEntry<'a>>>,
+    pub imports: Collection<'a, Loc<ImportsEntry<'a>>>,
     pub provides: Vec<'a, Loc<ExposesEntry<'a, &'a str>>>,
     pub to: Loc<To<'a>>,
 
@@ -147,7 +147,7 @@ pub struct PlatformHeader<'a> {
     pub requires: PlatformRequires<'a>,
     pub exposes: Vec<'a, Loc<ExposesEntry<'a, ModuleName<'a>>>>,
     pub packages: Collection<'a, Loc<PackageEntry<'a>>>,
-    pub imports: Vec<'a, Loc<ImportsEntry<'a>>>,
+    pub imports: Collection<'a, Loc<ImportsEntry<'a>>>,
     pub provides: Vec<'a, Loc<ExposesEntry<'a, &'a str>>>,
     pub effects: Effects<'a>,
 
@@ -196,7 +196,7 @@ impl<'a, T> Spaceable<'a> for ExposesEntry<'a, T> {
     }
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub enum ImportsEntry<'a> {
     /// e.g. `Task` or `Task.{ Task, after }`
     Module(

compiler/parse/src/module.rs

@@ -220,11 +220,11 @@ fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>, EHeader<'a>> {
         #[allow(clippy::type_complexity)]
         let opt_imports: Option<(
             (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-            Vec<'a, Located<ImportsEntry<'a>>>,
+            Collection<'a, Located<ImportsEntry<'a>>>,
         )> = opt_imports;
 
         let ((before_imports, after_imports), imports) =
-            opt_imports.unwrap_or_else(|| ((&[] as _, &[] as _), Vec::new_in(arena)));
+            opt_imports.unwrap_or_else(|| ((&[] as _, &[] as _), Collection::empty()));
         let provides: ProvidesTo<'a> = provides; // rustc must be told the type here
 
         let header = AppHeader {
@@ -631,7 +631,7 @@ fn imports<'a>() -> impl Parser<
     'a,
     (
         (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
-        Vec<'a, Located<ImportsEntry<'a>>>,
+        Collection<'a, Located<ImportsEntry<'a>>>,
     ),
     EImports,
 > {
@@ -646,14 +646,16 @@ fn imports<'a>() -> impl Parser<
             EImports::IndentImports,
             EImports::IndentListStart
         ),
-        collection_e!(
+        collection_trailing_sep_e!(
             word1(b'[', EImports::ListStart),
             loc!(imports_entry()),
             word1(b',', EImports::ListEnd),
             word1(b']', EImports::ListEnd),
             min_indent,
+            EImports::Open,
             EImports::Space,
-            EImports::IndentListEnd
+            EImports::IndentListEnd,
+            ImportsEntry::SpaceBefore
         )
     )
 }

compiler/parse/tests/test_parse.rs

@@ -3077,7 +3077,7 @@ mod test_parse {
     fn empty_app_header() {
         let arena = Bump::new();
         let packages = Collection::empty();
-        let imports = Vec::new_in(&arena);
+        let imports = Collection::empty();
         let provides = Vec::new_in(&arena);
         let module_name = StrLiteral::PlainLine("test-app");
         let header = AppHeader {
@@ -3117,7 +3117,7 @@ mod test_parse {
 
         let arena = Bump::new();
         let packages = Collection::empty();
-        let imports = Vec::new_in(&arena);
+        let imports = Collection::empty();
         let provides = Vec::new_in(&arena);
         let module_name = StrLiteral::PlainLine("test-app");
         let header = AppHeader {
@@ -3168,7 +3168,7 @@ mod test_parse {
         let packages = Collection::with_items(arena.alloc([loc_pkg_entry]));
         let import = ImportsEntry::Package("foo", ModuleName::new("Bar.Baz"), Collection::empty());
         let loc_import = Located::new(2, 2, 14, 25, import);
-        let imports = bumpalo::vec![in &arena; loc_import];
+        let imports = Collection::with_items(arena.alloc([loc_import]));
         let provide_entry = Located::new(3, 3, 15, 24, Exposed("quicksort"));
         let provides = bumpalo::vec![in &arena; provide_entry];
         let module_name = StrLiteral::PlainLine("quicksort");
@@ -3253,7 +3253,7 @@ mod test_parse {
             ),
         );
         let loc_import = Located::new(2, 6, 14, 5, import);
-        let imports = bumpalo::vec![in &arena; loc_import];
+        let imports = Collection::with_items(arena.alloc([loc_import]));
         let provide_entry = Located::new(7, 7, 15, 24, Exposed("quicksort"));
         let provides = bumpalo::vec![in &arena; provide_entry];
         let module_name = StrLiteral::PlainLine("quicksort");
@@ -3342,7 +3342,7 @@ mod test_parse {
             requires,
             exposes: Vec::new_in(&arena),
             packages: Collection::empty(),
-            imports: Vec::new_in(&arena),
+            imports: Collection::empty(),
             provides: Vec::new_in(&arena),
             effects,
             after_platform_keyword: &[],
@@ -3385,7 +3385,7 @@ mod test_parse {
         let loc_pkg_entry = Located::new(3, 3, 15, 27, pkg_entry);
         let arena = Bump::new();
         let packages = Collection::with_items(arena.alloc([loc_pkg_entry]));
-        let imports = Vec::new_in(&arena);
+        let imports = Collection::empty();
         let provide_entry = Located::new(5, 5, 15, 26, Exposed("mainForHost"));
         let provides = bumpalo::vec![in &arena; provide_entry];
         let effects = Effects {
@@ -3466,7 +3466,7 @@ mod test_parse {
     fn empty_interface_header() {
         let arena = Bump::new();
         let exposes = Vec::new_in(&arena);
-        let imports = Vec::new_in(&arena);
+        let imports = Collection::empty();
         let module_name = ModuleName::new("Foo");
         let header = InterfaceHeader {
             before_header: &[],
@@ -3498,7 +3498,7 @@ mod test_parse {
     fn nested_module() {
         let arena = Bump::new();
         let exposes = Vec::new_in(&arena);
-        let imports = Vec::new_in(&arena);
+        let imports = Collection::empty();
         let module_name = ModuleName::new("Foo.Bar.Baz");
         let header = InterfaceHeader {
             before_header: &[],