1 files changed, 41 insertions, 0 deletions
diff --git a/include/lexer.hpp b/include/lexer.hpp
new file mode 100644
index 0000000..73c5717
--- /dev/null
+++ b/include/lexer.hpp
@@ -0,0 +1,41 @@
+#include <string>
+
+#ifndef LEXER_H
+#define LEXER_H
+
+const std::string EMPTY_STRING = ""; 
+
+enum token_type{
+  sum,
+  substraction,
+  division,
+  multiplication,
+  power,
+  variable,
+  number,
+  sin,
+  cos,
+  tan,
+  function,
+  left_parens,
+  right_parens
+};
+
+struct Token{
+  token_type type;
+  std::string value;
+};
+
+class Lexer{
+private:
+  std::string text;
+  size_t txt_ptr;
+  Token current_token;
+  void setCurrentToken(Token val);
+public:
+  Lexer(std::string text);
+  void nextToken();
+  Token getCurrentToken();
+};
+
+#endif /* LEXER_H */