Function parse_condition_op

src/cypher/cypher.c:1077–1131

Parse the operator + value tail shared by every condition subject * (var[.prop] and multi-arg functions like coalesce(...)): IS [NOT] NULL, * IN [...], or a comparison operator with a literal value. */

 * (var[.prop] and multi-arg functions like coalesce(...)): IS [NOT] NULL,
 * IN [...], or a comparison operator with a literal value. */
static cbm_expr_t *parse_condition_op(parser_t *p, cbm_condition_t *c) {
    /* IS NULL / IS NOT NULL */
    if (check(p, TOK_IS)) {
        advance(p);
        if (match(p, TOK_NOT)) {
            c->op = heap_strdup("IS NOT NULL");
            expect(p, TOK_NULL_KW);
        } else {
            expect(p, TOK_NULL_KW);
            c->op = heap_strdup("IS NULL");
        }
        return expr_leaf(*c);
    }

    /* IN [...] */
    if (check(p, TOK_IN)) {
        cbm_expr_t *e = parse_in_list(p, c);
        if (!e) {
            cond_func_fields_free(c);
        }
        return e;
    }

    /* Standard operators */
    c->op = parse_comparison_op(p);
    if (!c->op) {
        snprintf(p->error, sizeof(p->error), "unexpected operator at pos %d", peek(p)->pos);
        cond_func_fields_free(c);
        safe_str_free(&c->variable);
        safe_str_free(&c->property);
        safe_str_free(&c->coalesce_default);
        return NULL;
    }

    /* Value */
    if (check(p, TOK_STRING) || check(p, TOK_NUMBER)) {
        c->value = heap_strdup(advance(p)->text);
    } else if (check(p, TOK_TRUE)) {
        advance(p);
        c->value = heap_strdup("true");
    } else if (check(p, TOK_FALSE)) {
        advance(p);
        c->value = heap_strdup("false");
    } else {
        snprintf(p->error, sizeof(p->error), "expected value at pos %d", peek(p)->pos);
        cond_func_fields_free(c);
        safe_str_free(&c->variable);
        safe_str_free(&c->property);
        safe_str_free(&c->op);
        safe_str_free(&c->coalesce_default);
        return NULL;
    }

    return expr_leaf(*c);
}

/* parse_condition_lhs result: the label-test form is a complete condition. */
enum { COND_LHS_COMPLETE = 1 };