message: Remove placeholder string thing in distiller
diff: @@ -14,8 +14,6 @@ pub struct Context<'interner, 'arena, 'env> {
  scope: &'arena Scope<'arena>,
  /// Rigid name environment.
  rigid_names: &'env mut UniqueEnv<Option<StringId>>,
  -
  - placeholder_string: StringId,
  }
  impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
  @@ -25,13 +23,10 @@ impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
  scope: &'arena Scope<'arena>,
  rigid_names: &'env mut UniqueEnv<Option<StringId>>,
  ) -> Context<'interner, 'arena, 'env> {
  - let placeholder_string = interner.borrow_mut().get_or_intern("_");
  -
  Context {
  interner,
  scope,
  rigid_names,
  - placeholder_string,
  }
  }
  @@ -44,7 +39,9 @@ impl<'interner, 'arena, 'env> Context<'interner, 'arena, 'env> {
  }
  fn push_rigid(&mut self, name: Option<StringId>) -> StringId {
  - let name = name.unwrap_or(self.placeholder_string); // TODO: choose a better name?
  + let name = name.unwrap_or_else(|| {
  + self.interner.borrow_mut().get_or_intern_static("_") // TODO: choose a better name?
  + });
  // TODO: avoid globals
  // TODO: ensure we chose a correctly bound name
  