Function apply_string_func

src/cypher/cypher.c:2907–2999

/* ── String function application ──────────────────────────────── */

static const char *apply_string_func(const char *func, const char *val, char *buf, size_t buf_sz) {
    if (!func || !val) {
        return val ? val : "";
    }
    if (strcmp(func, "toLower") == 0) {
        size_t i = 0;
        for (; i < buf_sz - SKIP_ONE && val[i]; i++) {
            buf[i] = (char)tolower((unsigned char)val[i]);
        }
        buf[i] = '\0';
        return buf;
    }
    if (strcmp(func, "toUpper") == 0) {
        size_t i = 0;
        for (; i < buf_sz - SKIP_ONE && val[i]; i++) {
            buf[i] = (char)toupper((unsigned char)val[i]);
        }
        buf[i] = '\0';
        return buf;
    }
    if (strcmp(func, "toString") == 0) {
        return val; /* already strings */
    }
    if (strcmp(func, "toInteger") == 0) {
        char *end = NULL;
        long long v = strtoll(val, &end, CBM_DECIMAL_BASE);
        if (end == val) {
            /* Not an integer literal — accept a float string and truncate. */
            char *fend = NULL;
            double d = strtod(val, &fend);
            if (fend == val) {
                return ""; /* non-numeric → null */
            }
            v = (long long)d;
        }
        snprintf(buf, buf_sz, "%lld", v);
        return buf;
    }
    if (strcmp(func, "toFloat") == 0) {
        char *end = NULL;
        double d = strtod(val, &end);
        if (end == val) {
            return ""; /* non-numeric → null */
        }
        snprintf(buf, buf_sz, "%g", d);
        return buf;
    }
    if (strcmp(func, "toBoolean") == 0) {
        if (cyp_ci_eq(val, "true")) {
            return "true";
        }
        if (cyp_ci_eq(val, "false")) {
            return "false";
        }
        return ""; /* not a boolean → null */
    }
    if (strcmp(func, "size") == 0 || strcmp(func, "length") == 0) {
        snprintf(buf, buf_sz, "%zu", strlen(val));