19.2 An Overview of the Reentrant API

The API for reentrant scanners is different than for non-reentrant scanners. Here is a quick overview of the API:

• %option reentrant must be specified.
• All functions take one additional argument: yyscanner
• All global variables are replaced by their macro equivalents. (We tell you this because it may be important to you during debugging.)
• yylex_init and yylex_destroy must be called before and after yylex, respectively.
• Accessor methods (get/set functions) provide access to common flex variables.
• User-specific data can be stored in yyextra.