From 27a8de70facd6d5a13c43425b4715ac6eacb4ba7 Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Thu, 29 Apr 2021 09:47:29 +0200
Subject: [PATCH] Bugfix: Peeking - Fixed `PeekableLexer` next to not-be
 passtrough to iterator - Made error handling depend on state of Option

---
 src/lexer.rs        |  5 ++++-
 src/parser/ops.rs   |  1 +
 src/parser/utils.rs | 12 ++++++++----
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/lexer.rs b/src/lexer.rs
index dbe33a8..f3038e4 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -53,7 +53,10 @@ impl<'source> Iterator for PeekableLexer<'source> {
     /// again may or may not eventually start returning [`Some(Item)`] again at some point.
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
-        self.lexer.next()
+        match self.peeked.take() {
+            Some(v) => v,
+            None => self.lexer.next(),
+        }
     }
 }
 
diff --git a/src/parser/ops.rs b/src/parser/ops.rs
index 2b76e68..fb22c30 100644
--- a/src/parser/ops.rs
+++ b/src/parser/ops.rs
@@ -21,6 +21,7 @@ impl<'a> Parser<'a> {
     }
 
     fn fn_call(&mut self, iden: Iden) -> Result<Expr, Error> {
+        self.lexer.next();
         self.require(Token::RightParenthesis)?;
         Ok(Expr::FunctionCall {
             iden,
diff --git a/src/parser/utils.rs b/src/parser/utils.rs
index 49c8b34..eddfbea 100644
--- a/src/parser/utils.rs
+++ b/src/parser/utils.rs
@@ -42,12 +42,16 @@ impl<'a> Parser<'a> {
     }
 
     pub(super) fn unexpected_token(&mut self, expected: Option<Token>) -> Error {
-        Error {
-            kind: ErrorKind::SyntaxError(format!(
+        let error_msg = match expected {
+            Some(s) => format!(
                 "Unexpected token: `{}` (required: `{:?}`)",
                 self.lexer.slice(),
-                expected
-            )),
+                s
+            ),
+            None => format!("Unexpected token: `{}`)", self.lexer.slice(),),
+        };
+        Error {
+            kind: ErrorKind::SyntaxError(error_msg),
             position: self.lexer.span(),
         }
     }