bug fixes and performance improvements

src/pipeline/split_name.rs

@@ -0,0 +1,14 @@
+use crate::interner::Token;
+
+pub fn split_name<'a>(
+  path: &'a [Token<String>],
+  is_valid: &impl Fn(&[Token<String>]) -> bool
+) -> Option<(&'a [Token<String>], &'a [Token<String>])> {
+  for split in (0..=path.len()).rev() {
+    let (filename, subpath) = path.split_at(split);
+    if is_valid(filename) {
+      return Some((filename, subpath))
+    }
+  }
+  None
+}