Token to_string now include source name and is printed error style

So instead of the previous weird format, we have the format
<source_name>:<line>:<column>: <TYPE> which also allows me to quickly
go to that token via Emacs' (compile).

src/lexer.cpp

@@ -556,13 +556,13 @@ namespace Lexer
   std::string to_string(const Token &t)
   {
     std::stringstream stream;
-    stream << to_string(t.type);
+    stream << t.source_name << ":" << t.line << ":" << t.column << ": "
+           << to_string(t.type);
 
     if (t.operand_type != Token::OperandType::NIL)
       stream << "[" << to_string(t.operand_type) << "]";
     if (t.content != "")
       stream << "(`" << t.content << "`)";
-    stream << "@" << t.line << ", " << t.column;
     return stream.str();
   }
 

src/lexer.hpp

@@ -114,7 +114,7 @@ namespace Lexer
 
     Err();
 
-    Err(Type type, size_t col, size_t line, std::string_view source_name);
+    Err(Type type, size_t col, size_t line, std::string_view source_name = "");
   };
 
   Err tokenise_buffer(std::string_view source_name, std::string_view content,

src/main.cpp

@@ -70,7 +70,7 @@ int main(int argc, const char *argv[])
   string source_str;
   string_view original;
   string_view src;
-  vector<Token *> tokens, preprocessed_tokens;
+  vector<Token *> tokens;
   Lex_Err lerr;
 
   // Highest scoped variable cut off point
@@ -87,7 +87,7 @@ int main(int argc, const char *argv[])
   src      = string_view{source_str};
   lerr     = tokenise_buffer(source_name, src, tokens);
 
-  if (lerr.type != Lexer ::Err::Type::OK)
+  if (lerr.type != Lex_Err::Type::OK)
   {
     cerr << lerr << endl;
     ret = 255 - static_cast<int>(lerr.type);
@@ -95,7 +95,6 @@ int main(int argc, const char *argv[])
   }
   else
   {
-
 #if VERBOSE >= 1
     printf("[%sLEXER%s]: %lu bytes -> %lu tokens\n", TERM_GREEN, TERM_RESET,
            source_str.size(), tokens.size());