flex: Extra Reentrant Argument
19.4.2 The Extra Argument
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All functions take one additional argument: 'yyscanner'.
Notice that the calls to 'yy_push_state' and 'yy_pop_state' both have
an argument, 'yyscanner' , that is not present in a non-reentrant
scanner. Here are the declarations of 'yy_push_state' and
'yy_pop_state' in the reentrant scanner:
static void yy_push_state ( int new_state , yyscan_t yyscanner ) ;
static void yy_pop_state ( yyscan_t yyscanner ) ;
Notice that the argument 'yyscanner' appears in the declaration of
both functions. In fact, all 'flex' functions in a reentrant scanner
have this additional argument. It is always the last argument in the
argument list, it is always of type 'yyscan_t' (which is typedef'd to
'void *') and it is always named 'yyscanner'. As you may have guessed,
'yyscanner' is a pointer to an opaque data structure encapsulating the
current state of the scanner. For a list of function declarations, see
⇒Reentrant Functions. Note that preprocessor macros, such as
'BEGIN', 'ECHO', and 'REJECT', do not take this additional argument.
Info Catalog
flex: Specify Reentrant
flex: Reentrant Detail
flex: Global Replacement