Added simple rules for literals based on documentation. Still have to test them and refine further

lexicalStructure.lex

@@ -7,6 +7,17 @@
  %} 
 
 %%
-//rules
+/* rules */
+[0-9]+ {printf( "C_INTEGER: %s (%d)\n", yytext, atoi( yytext ) );}
+
+"null" {printf( "C_NULL: %s (%d)\n", yytext, atoi( yytext ) );}
+
+['][.]['] | [']\\[nt'\\]['] {printf( "C_CHARACTER: %s (%d)\n", yytext, atoi( yytext ) );} /*using double \ per documentation to show escaped chars*/
+
+"true" {printf( "C_TRUE: %s (%d)\n", yytext, atoi( yytext ) );}
+
+"false" {printf( "C_FALSE: %s (%d)\n", yytext, atoi( yytext ) );}
+
+["][.]+["] {printf( "C_STRING: %s (%d)\n", yytext, atoi( yytext ) );}
 %%
-//user code
+/* user code */