Add "production" line to parse debug output

And also add a .next() in the parser that should've been there

schala-lang/language/src/parsing.rs

@@ -825,6 +825,7 @@ impl Parser {
     let lhs = self.prefix_expr()?;
     let ref next = self.token_handler.peek_kind();
     Ok(if let Some(op) = BinOp::from_sigil_token(next) {
+      self.token_handler.next();
       Discriminator::BinOp(lhs, op)
     } else {
       Discriminator::Simple(lhs)

schala-lang/language/src/schala.rs

@@ -127,12 +127,18 @@ fn format_parse_error(error: parsing::ParseError, handle: &mut Schala) -> String
   let line_num_digits = format!("{}", line_num).chars().count();
   let space_padding = " ".repeat(line_num_digits);
 
+  let production = match error.production_name {
+    Some(n) => format!("\n(from production \"{}\")", n),
+    None => "".to_string()
+  };
+
   format!(r#"
-{error_msg}
+{error_msg}{production}
 {space_padding} |
 {line_num} | {}
 {space_padding} | {}
-"#, line_from_program, location_pointer, error_msg=error.msg, space_padding=space_padding, line_num=line_num)
+"#, line_from_program, location_pointer, error_msg=error.msg, space_padding=space_padding, line_num=line_num, production=production
+)
 }
 
 fn symbol_table(input: ast::AST, handle: &mut Schala, comp: Option<&mut PassDebugArtifact>) -> Result<ast::AST, String> {