d50a3e450e
That change was started in Bison 3.4. The announcement for 3.7 stated that in Bison 3.8 we would use *.gv by default. * src/files.c (compute_output_file_names): spec_graph_file defaults too *.gv. * doc/bison.texi, examples/c++/calc++/local.mk, tests/output.at: Adjust.
calc++ - A Flex+Bison calculator
This directory contains calc++, a Bison grammar file in C++. If you never saw the traditional implementation in C, please first read examples/c/lexcalc, which can be seen as a C precursor of this example.
Read the corresponding chapter in the documentation: "A Complete C++ Example". It is also available on line (maybe with a different version of Bison).
To use it, copy this directory into some work directory, and run make to
compile the executable, and try it. It is a simple calculator which accepts
several variable definitions, one per line, and then a single expression to
evaluate.
The program calc++ expects the file to parse as argument; pass - to read
the standard input (and then hit , control-d, to end your input).
$ ./calc++ -
one := 1
two := 2
three := 3
(one + two * three) * two * three
<Ctrl-d>
42
You may pass -p to activate the parser debug traces, and -s to activate
the scanner's.