On 21/12/13 03:57, Josh Stratton wrote:
I'm completely new to guile and am trying to find a simple example of
evaluating a string inside C with some kind of context. I want to
execute small self-contained strings provided by a user. I've looked
at various examples, but everything I've seen seems uses the shell,
which seems like more than I need. The context doesn't need to
persist between evals.
Is there an example that would allow me to do something like this?
float evaluateExpression(char* expression)
{
if (!initialized) {
scm_init_guile();
initialized = true;
}
// making stuff up here
some_guile_context = ...
some_guile_context.add("someDef", 5); // add some definitionos the
expression might expect to be defined
some_guile_response = some_guile_context.eval(expression); //
expression might use "someDef" like (* someDef 8)
return scm_arg_to_float(scm_guile_response[0]);
}
http://www.gnu.org/software/guile/manual/html_node/Fly-Evaluation.html
SCM r = scm_c_eval_string(expression);
if (scm_is_true(scm_number_p(r))
value = scm_to_double(r);
But you will probably want to wrap the evaluation of expression in a
scm_catch().
P.
