to_s

static VALUE
proc_to_s(VALUE self)
{
    VALUE str = 0;
    rb_proc_t *proc;
    const char *cname = rb_obj_classname(self);
    rb_iseq_t *iseq;
    const char *is_lambda;

    GetProcPtr(self, proc);
    iseq = proc->block.iseq;
    is_lambda = proc->is_lambda ? " (lambda)" : "";

    if (RUBY_VM_NORMAL_ISEQ_P(iseq)) {
        int first_lineno = 0;

        if (iseq->line_info_table) {
            first_lineno = FIX2INT(rb_iseq_first_lineno(iseq->self));
        }
        str = rb_sprintf("#<%s:%p@%"PRIsVALUE":%d%s>", cname, (void *)self,
                         iseq->location.path, first_lineno, is_lambda);
    }
    else {
        str = rb_sprintf("#<%s:%p%s>", cname, (void *)proc->block.iseq,
                         is_lambda);
    }

    if (OBJ_TAINTED(self)) {
        OBJ_TAINT(str);
    }
    return str;
}