a question about yyrestart & reusing a scanner

[Cheng Po-wen]

Hi,

I have a a question about how to reuse a scanner,
The document (which is flex.pdf -- Flex, version 2.5.31) says

there is no need to destroy a scanner if you plan to reuse it. A flex
scanner (both reentrant
and non-reentrant) may be restarted by calling yyrestart

my question is :

1. Is it safe, for a long lived applicaion to reuse a scanner all the
time by calling
yyrestart(..) ?

will there be any dangling resources, which are not released or freed by
doing so???

2. Does yy_scan_buffer (or yy_scan_string) internally do the "yyrestart
things" ?

what I mean is my scanner scans "strings", instead of "stdin".
so, if i want to reuse a scanner,
do I have to call yyrestart(NULL , my_scanner), and then call
yy_scan_buffer(.....) ???

or I can just call yy_scan_buffer(.....), and it internally does the
"yyrestart things" ?

THANX

Sting



The function yylex_destroy should be called to free resources used by
the scanner.
After yylex_destroy is called, the contents of yyscanner should not be
used. Of course,
there is no need to destroy a scanner if you plan to reuse it. A flex
scanner (both reentrant
and non-reentrant) may be restarted by calling yyrestart

-- 
Sting, Cheng Po-wen(鄭博文)
Phone :  886-3-5914545  Fax : 886-3-5820085
E-Mail : address@hidden

Internet Software Technology Division(W100)
Computer & Communication Research Lab. / ITRI