[Flex-devel] Suggestions for improvement

[Joe K. <kr...@ni...>]

Here are some suggestions for updating Flex. Is it good to mail patches 
to this list?

Several newer(?) functions should probably be included in the options 
for not generating code, such as "%option noyyget_column noyyset_column"

When the option is used to generate a public header, the scanner source 
file should #include that header rather than duplicating the contents in 
the source file. Otherwise, user code that include that header (directly 
or indirectly) gets duplicate declarations. At the very least, generated 
source should pre-define the header's include guard macro.

Flex has functions yyset_lval() and yyset_lloc() so that the scanner 
globals can be set in reentrant mode, without having to pass them as 
arguments on every call to yylex(). Unfortunately, those functions are 
generated ONLY with bison-bridge options, which also forces them to be 
yylex arguments. My suggestion is to always generate the lval and lloc 
set/get functions in reentrant mode, unless options noyyset_lval, etc., 
are given.

The main reason Flex has memory allocation wrappers seems to be to avoid 
errors for older standards that use (char*) for memory pointers. Why not 
include a flag to directly use malloc, etc.? Or maybe an option to 
define them as inline, to get the same effect?

Joe Krahn