feat: implemented lexer-backed error builder, error messages are now based on predefined tokens

Co-authored-by: gc1523

src/main/wacc/lexer.scala

@@ -80,5 +80,15 @@ object lexer {
   val stringLit = lexer.lexeme.string.ascii
   val implicits = lexer.lexeme.symbol.implicits
 
+  val errTokens = Seq(
+    lexer.nonlexeme.names.identifier.map(v => s"identifier $v"),
+    lexer.nonlexeme.integer.decimal32[Int].map(n => s"integer $n"),
+    lexer.nonlexeme.character.ascii.map(c => s"character literal $c"),
+    lexer.nonlexeme.string.ascii.map(s => s"string literal $s"),
+    character.whitespace.map(_ => "")
+  ) ++ desc.symbolDesc.hardKeywords.map { k =>
+    lexer.nonlexeme.symbol(k).as(s"keyword $k")
+  }
+
   def fully[A](p: Parsley[A]): Parsley[A] = lexer.fully(p)
 }