end of file on Mac OS X

[Steven Eker]

I've noticed that yyinput()/input() returns 0 rather than EOF when it
hits the end of the file. On Linux the expected EOF is returned.

Mac OS X:

ape:Mixfix eker$ flex --version
flex 2.5.35 Apple(flex-31)

Linux:

psi:Mixfix > flex --version
flex 2.5.35

If I examine the C/C++ code generated, there is indeed a difference at
the relevant line in yyinput()/input():

Mac:

case EOB_ACT_END_OF_FILE:
{
if ( yywrap( ) )
return 0;

if ( !
(yy_did_buffer_switch_on_eof) )
YY_NEW_FILE;
#ifdef __cplusplus
return yyinput();
#else
return input();
#endif
}

Linux:

case EOB_ACT_END_OF_FILE:
{
if ( yywrap( ) )
return EOF;

if ( !
(yy_did_buffer_switch_on_eof) )
YY_NEW_FILE;
#ifdef __cplusplus
return yyinput();
#else
return input();
#endif
}

So is this a bug (in the Mac version) or is this weirdness documented
somewhere?

Steven Eker
http://www.csl.sri.com/people/eker/