From 4dcd9d019801de699f9d659b2ed2fca5c880f830 Mon Sep 17 00:00:00 2001
From: greg <greg.shuflin@protonmail.com>
Date: Tue, 22 Oct 2019 02:11:49 -0700
Subject: [PATCH] Some more parse trace improvements

---
 schala-lang/language/src/parsing.rs    | 9 ++++++++-
 schala-lang/language/src/tokenizing.rs | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/schala-lang/language/src/parsing.rs b/schala-lang/language/src/parsing.rs
index da97c3c..f78911c 100644
--- a/schala-lang/language/src/parsing.rs
+++ b/schala-lang/language/src/parsing.rs
@@ -263,12 +263,19 @@ impl Parser {
   pub fn format_parse_trace(&self) -> String {
     let mut buf = String::new();
     buf.push_str("Parse productions:\n");
+    let mut next_token = None;
     for r in self.parse_record.iter() {
       let mut indent = String::new();
       for _ in 0..r.level {
         indent.push('.');
       }
-      buf.push_str(&format!("{}`{}`, next token: {}\n", indent, r.production_name, r.next_token))
+      let effective_token = if next_token == Some(&r.next_token) {
+        "".to_string()
+      } else {
+        next_token = Some(&r.next_token);
+        format!(", next token: {}", r.next_token)
+      };
+      buf.push_str(&format!("{}`{}`{}\n", indent, r.production_name, effective_token));
     }
     buf
   }
diff --git a/schala-lang/language/src/tokenizing.rs b/schala-lang/language/src/tokenizing.rs
index 7939f31..e4abbd0 100644
--- a/schala-lang/language/src/tokenizing.rs
+++ b/schala-lang/language/src/tokenizing.rs
@@ -86,7 +86,7 @@ lazy_static! {
     };
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct Token {
   pub kind: TokenKind,
   pub line_num: usize,