From 6585366b0d832de170ca831b3693d5dab9f962e9 Mon Sep 17 00:00:00 2001
From: Kasper <kasperkh.kh@gmail.com>
Date: Wed, 21 Apr 2021 21:06:02 +0200
Subject: [PATCH] Fix panic when input contains only whitespace and/or commas

---
 src/lexer.rs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/lexer.rs b/src/lexer.rs
index 142bc89..8d25895 100644
--- a/src/lexer.rs
+++ b/src/lexer.rs
@@ -21,10 +21,6 @@ pub const fn is_alphabetic_extended(input: &char) -> bool {
 /// Lex an input string and return a [`TokenVector`]
 pub fn lex(input: &str, allow_trailing_operators: bool, default_degree: Unit) -> Result<TokenVector, String> {
 
-  if input == "" {
-    return Err(format!("Input was empty"))
-  }
-
   let mut input = input.replace(",", ""); // ignore commas
   input = input.to_lowercase();
 
@@ -399,8 +395,6 @@ pub fn lex(input: &str, allow_trailing_operators: bool, default_degree: Unit) ->
             }
           }
         }
-
-        
       },
       '.' | '0'..='9' => {
         let start_index = byte_index;
@@ -455,6 +449,10 @@ pub fn lex(input: &str, allow_trailing_operators: bool, default_degree: Unit) ->
     }
   }
 
+  if tokens.len() == 0 {
+    return Err(format!("Input was empty"))
+  }
+
   let mut token_index = 0;
   loop {
     match tokens[token_index] {