Parse app module headers.

compiler/parse/src/ast.rs

@@ -36,9 +36,14 @@ pub struct WhenBranch<'a> {
 
 #[derive(Clone, Debug, PartialEq)]
 pub struct AppHeader<'a> {
+    pub name: Loc<ModuleName<'a>>,
+    pub provides: Vec<'a, Loc<ExposesEntry<'a>>>,
     pub imports: Vec<'a, Loc<ImportsEntry<'a>>>,
 
     // Potential comments and newlines - these will typically all be empty.
+    pub after_interface: &'a [CommentOrNewline<'a>],
+    pub before_provides: &'a [CommentOrNewline<'a>],
+    pub after_provides: &'a [CommentOrNewline<'a>],
     pub before_imports: &'a [CommentOrNewline<'a>],
     pub after_imports: &'a [CommentOrNewline<'a>],
 }

compiler/parse/src/module.rs

@@ -127,9 +127,30 @@ pub fn module_name<'a>() -> impl Parser<'a, ModuleName<'a>> {
 
 #[inline(always)]
 fn app_header<'a>() -> impl Parser<'a, AppHeader<'a>> {
-    move |_, _| {
-        panic!("TODO parse app header");
-    }
+    parser::map(
+        and!(
+            skip_first!(string("app"), and!(space1(1), loc!(module_name()))),
+            and!(provides(), imports())
+        ),
+        |(
+            (after_interface, name),
+            (
+                ((before_provides, after_provides), provides),
+                ((before_imports, after_imports), imports),
+            ),
+        )| {
+            AppHeader {
+                name,
+                provides,
+                imports,
+                after_interface,
+                before_provides,
+                after_provides,
+                before_imports,
+                after_imports,
+            }
+        },
+    )
 }
 
 #[inline(always)]
@@ -137,6 +158,20 @@ pub fn module_defs<'a>() -> impl Parser<'a, Vec<'a, Located<Def<'a>>>> {
     zero_or_more!(space0_around(loc(def(0)), 0))
 }
 
+#[inline(always)]
+fn provides<'a>() -> impl Parser<
+    'a,
+    (
+        (&'a [CommentOrNewline<'a>], &'a [CommentOrNewline<'a>]),
+        Vec<'a, Located<ExposesEntry<'a>>>,
+    ),
+> {
+    and!(
+        and!(skip_second!(space1(1), string("provides")), space1(1)),
+        collection!(char('['), loc!(exposes_entry()), char(','), char(']'), 1)
+    )
+}
+
 #[inline(always)]
 fn exposes<'a>() -> impl Parser<
     'a,