bug fixes and performance improvements

src/rule/rule_error.rs

@@ -1,18 +1,36 @@
-use std::{fmt, error::Error};
+use std::fmt;
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+use crate::interner::{Token, InternedDisplay, Interner};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum RuleError {
-  BadState(String),
-  ScalarVecMismatch(String)
+  Missing(Token<String>),
+  TypeMismatch(Token<String>),
+  /// Multiple occurences of a placeholder in a pattern are no longer
+  /// supported.
+  Multiple(Token<String>),
+  VecNeighbors(Token<String>, Token<String>),
 }
 
-impl fmt::Display for RuleError {
-  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-    match self {
-      Self::BadState(key) => write!(f, "Key {:?} not in match pattern", key),
-      Self::ScalarVecMismatch(key) =>
-        write!(f, "Key {:?} used inconsistently with and without ellipsis", key)
+impl InternedDisplay for RuleError {
+  fn fmt_i(&self, f: &mut fmt::Formatter<'_>, i: &Interner) -> fmt::Result {
+    match *self {
+      Self::Missing(key) => write!(f,
+        "Key {:?} not in match pattern",
+        i.r(key)
+      ),
+      Self::TypeMismatch(key) => write!(f,
+        "Key {:?} used inconsistently with and without ellipsis",
+        i.r(key)
+      ),
+      Self::Multiple(key) => write!(f,
+        "Key {:?} appears multiple times in match pattern",
+        i.r(key)
+      ),
+      Self::VecNeighbors(left, right) => write!(f,
+        "Keys {:?} and {:?} are two vectorials right next to each other",
+        i.r(left), i.r(right)
+      )
     }
   }
-}
-impl Error for RuleError {}
+}