void generate_precondition_next(ast::tree& ast, ast::node* root, unsigned branch_index, formatter& output)
{
plnnrc_assert(is_logical_op(root));
output.writeln("bool next(p%d_state& state, worldstate& world)", branch_index);
{
scope s(output);
output.writeln("PLNNR_COROUTINE_BEGIN(state);");
output.newline();
generate_precondition_satisfier(ast, root, output);
output.writeln("PLNNR_COROUTINE_END();");
}
}
// expression = term { add_op term } |
// expression "?" expression ":" expression
// expression logical_op expression
// variable "=" expression
// add_op = "+" | "-"
static enum v7_err parse_expression(struct v7 *v7) {
#ifdef V7_DEBUG
const char *stmt_str = v7->cursor;
#endif
int op;
v7->cur_obj = &v7->scopes[v7->current_scope];
TRY(parse_term(v7));
while (*v7->cursor == '-' || *v7->cursor == '+') {
int ch = *v7->cursor;
TRY(match(v7, ch));
TRY(parse_term(v7));
TRY(do_arithmetic_op(v7, ch));
}
if ((op = is_logical_op(v7->cursor)) > OP_XX) {
v7->cursor += op == OP_LT || op == OP_GT ? 1 : 2;
skip_whitespaces_and_comments(v7);
TRY(parse_expression(v7));
TRY(do_logical_op(v7, op));
}
// Parse assignment
if (*v7->cursor == '=') {
//printf("=> cur_obj: %p\n", cur_obj);
TRY(parse_assignment(v7, v7->cur_obj));
}
// Parse ternary operator
if (*v7->cursor == '?') {
int condition_true = v7_is_true(v7_top(v7)[-1]);
int old_no_exec = v7->no_exec;
TRY(match(v7, '?'));
v7->no_exec = old_no_exec || !condition_true;
TRY(parse_expression(v7));
TRY(match(v7, ':'));
v7->no_exec = old_no_exec || condition_true;
TRY(parse_expression(v7));
v7->no_exec = old_no_exec;
}
return V7_OK;
}