Fixing bugs, pointer arithmetic checking, better for, working on first program

program.c

@@ -16,20 +16,36 @@ typedef U64      SizeU;
 typedef S64      SizeS;
 typedef float    F32;
 typedef double   F64;
+typedef S32     Bool;
 
 typedef struct String{
   U8 *str;
   S64 len;
 }String;
 #define LIT(x) (String){.str=(U8 *)x, .len=sizeof(x)-1}
-  
-struct Lex_Stream{
-  U8 *stream;
-  U8 *end;
-};
+
+void entry();
 int main(){
+  entry();
+}
+  
+typedef struct Token{
+  U8 *str;
+  S64 len;
+}Token;
+Bool is_numeric(U8 c){
+  Bool result = ((c>=48)&&(c<=57));
+  return result;
+}
+void entry(){
   String string_to_lex = LIT("Identifier 2425525 Not_Number");
+  Token t;
   for(S64 i = 0;(i<string_to_lex.len);(i+=1)){
-    (string_to_lex.str[0]=64);
+    if(is_numeric((string_to_lex.str[i]))){
+      (t.str=(&(string_to_lex.str[i])));
+      for(;is_numeric((string_to_lex.str[i]));){
+        (i+=1);
+      }
+    }
   }
 }