Expose unsupported lookups

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "font"
-version = "0.35.1"
+version = "0.36.0"
 edition = "2021"
 license = "Apache-2.0/MIT"
 authors = ["Ivan Ukhov <ivan.ukhov@gmail.com>"]

src/formats/opentype/features/mod.rs

@@ -28,7 +28,7 @@ pub struct Directory {
     /// Features to samples.
     pub features: Vec<(Feature, Vec<usize>)>,
     /// Samples.
-    pub samples: Vec<Option<Vec<BTreeSet<Sample>>>>,
+    pub samples: Vec<Vec<Option<BTreeSet<Sample>>>>,
 }
 
 pub(crate) fn read<T: crate::Read>(cache: &mut Cache<T>) -> Result<Directory> {
@@ -97,8 +97,8 @@ fn process_table<T>(
         HashMap<(Feature, Vec<usize>), usize>,
     ),
     samples: &mut (
-        Vec<Option<Vec<BTreeSet<Sample>>>>,
-        HashMap<Option<Vec<BTreeSet<Sample>>>, usize>,
+        Vec<Vec<Option<BTreeSet<Sample>>>>,
+        HashMap<Vec<Option<BTreeSet<Sample>>>, usize>,
     ),
 ) -> Option<()>
 where
@@ -125,8 +125,8 @@ fn process_graphs<T>(
     directory: &layout::Directory<T>,
     mapping: &Mapping,
     samples: &mut (
-        Vec<Option<Vec<BTreeSet<Sample>>>>,
-        HashMap<Option<Vec<BTreeSet<Sample>>>, usize>,
+        Vec<Vec<Option<BTreeSet<Sample>>>>,
+        HashMap<Vec<Option<BTreeSet<Sample>>>, usize>,
     ),
 ) -> Vec<usize>
 where

src/formats/opentype/features/rules.rs

@@ -267,13 +267,11 @@ impl Table for opentype::tables::glyph_substitution::Type {
                     table.glyph_ids.iter().cloned().map(Into::into).collect(),
                 )));
             }
-            _ => {}
-        }
-        if !values.is_empty() {
-            Some(values)
-        } else {
-            None
+            _ => {
+                return None;
+            }
         }
+        Some(values)
     }
 }
 

src/formats/opentype/features/transform.rs

@@ -14,7 +14,7 @@ pub trait Transform<'l> {
 }
 
 impl<'l> Transform<'l> for &[Option<Rules>] {
-    type Target = Option<Vec<BTreeSet<Sample>>>;
+    type Target = Vec<Option<BTreeSet<Sample>>>;
     type Parameter = &'l [Vec<Option<Rules>>];
 
     fn transform(self, mapping: &Mapping, rules: Self::Parameter) -> Self::Target {