sys/fmt: move _is_digit and _is_upper to public API

sys/fmt/fmt.c

@@ -48,16 +48,6 @@ static const uint32_t _tenmap[] = {
 
 #define TENMAP_SIZE  ARRAY_SIZE(_tenmap)
 
-static inline int _is_digit(char c)
-{
-    return (c >= '0' && c <= '9');
-}
-
-static inline int _is_upper(char c)
-{
-    return (c >= 'A' && c <= 'Z');
-}
-
 static inline char _to_lower(char c)
 {
     return 'a' + (c - 'A');
@@ -437,7 +427,7 @@ size_t fmt_to_lower(char *out, const char *str)
     size_t len = 0;
 
     while (str && *str) {
-        if (_is_upper(*str)) {
+        if (fmt_is_upper(*str)) {
             if (out) {
                 *out++ = _to_lower(*str);
             }
@@ -457,7 +447,7 @@ uint32_t scn_u32_dec(const char *str, size_t n)
     uint32_t res = 0;
     while(n--) {
         char c = *str++;
-        if (!_is_digit(c)) {
+        if (!fmt_is_digit(c)) {
             break;
         }
         else {
@@ -474,8 +464,8 @@ uint32_t scn_u32_hex(const char *str, size_t n)
 
     while (n--) {
         char c = *str++;
-        if (!_is_digit(c)) {
-            if (_is_upper(c)) {
+        if (!fmt_is_digit(c)) {
+            if (fmt_is_upper(c)) {
                 c = _to_lower(c);
             }
             if (c == '\0' || c > 'f') {

sys/include/fmt.h

@@ -45,6 +45,30 @@ extern "C" {
 #define FMT_USE_MEMMOVE (1) /**< use memmove() or internal implementation */
 #endif
 
+/**
+ * @brief   Test if the given character is a numerical digit (regex `[0-9]`)
+ *
+ * @param[in] c     Character to test
+ *
+ * @return  true if @p c is a digit, false otherwise
+ */
+static inline int fmt_is_digit(char c)
+{
+    return (c >= '0' && c <= '9');
+}
+
+/**
+ * @brief   Test if the given character is an uppercase letter (regex `[A-Z]`)
+ *
+ * @param[in] c     Character to test
+ *
+ * @return  true if @p c is an uppercase letter, false otherwise
+ */
+static inline int fmt_is_upper(char c)
+{
+    return (c >= 'A' && c <= 'Z');
+}
+
 /**
  * @brief Format a byte value as hex
  *