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1934304acf
Reported by Bruno Haible. http://lists.gnu.org/archive/html/bug-bison/2019-05/msg00026.html * configure.ac (FLEX_WORKS): New. * examples/c/lexcalc/local.mk, examples/c/reccalc/local.mk: Use it.
reccalc - recursive calculator with Flex and Bison
In this example the generated parser is pure and reentrant: it can be used concurrently in different threads, or recursively. As a proof of this reentrancy, expressions in parenthesis are tokenized as strings, and then recursively parsed from the parser:
exp: STR
{
result r = parse_string ($1);
free ($1);
if (r.nerrs)
{
res->nerrs += r.nerrs;
YYERROR;
}
else
$$ = r.value;
}