parse sign

headers/errors.h

@@ -9,8 +9,9 @@ typedef enum
     ERROR_UNKNOWN_TOKEN = -1,
     ERROR_NUMBER_TOO_BIG = -2,
     ERROR_PARSING = -3,
+    ERROR_TOKEN_POSITION = -4,
 } program_error;
 
-int stop_errors(int err, const char *details);
+int stop_errors(program_error err, const char *details);
 
 #endif

headers/lexer.h

@@ -7,13 +7,14 @@
 
 typedef enum
 {
-    TOKEN_VARIABLE, // x, y, etc.
-    TOKEN_NUMBER,   // int or double -> all converted into double
-    TOKEN_POWER,    // ^ or **
-    TOKEN_SIGN,     // + or -
-    TOKEN_FACTOR,   // * or /
-    TOKEN_EQUAL,    // =
-    TOKEN_END       // null (end of input)
+    TOKEN_VARIABLE,      // x, y, etc.
+    TOKEN_NUMBER_INT,    // int
+    TOKEN_NUMBER_DOUBLE, // double
+    TOKEN_POWER,         // ^ or **
+    TOKEN_SIGN,          // + or -
+    TOKEN_FACTOR,        // * or /
+    TOKEN_EQUAL,         // =
+    TOKEN_END            // null (end of input)
 } token_type;
 
 typedef struct
@@ -22,6 +23,7 @@ typedef struct
     union
     {
         char value_char;
+        int value_int;
         double value_double;
     };
 } token;