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Prompted by Rici Lake. https://stackoverflow.com/questions/62658368/#comment110853985_62661621 Discussed with Paul Eggert. * doc/bison.texi, examples/c/bistromathic/parse.y, * examples/c/lexcalc/parse.y, examples/c/lexcalc/scan.l, * examples/c/pushcalc/calc.y, examples/c/reccalc/parse.y, * examples/c/reccalc/scan.l, examples/d/calc.y, * examples/java/calc/Calc.y, examples/java/simple/Calc.y: Install the GPL3+ header.
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;
}