extern int x1f4_peek_expression (void *x1f4_expression, void *data, int (*this)(void *, const struct x1f4_function_type *));
x1f4_peek_expression function lists the symbolic function occurences
x1f4_expression parsed expression representation by calling the
this method with the function listing
data context and the
symbolic function definition as parameters for each variable occurence, for as
this returns 0.
See struct x1f4_function_type.
The function returns
this was never called or never returned
non zero, the first (and only) non zero return of