Add utils::is_double and utils::is_integer

src/utils.cpp

@@ -348,6 +348,40 @@ size_t utils::count_words(const std::string & text, const std::string & seperato
   return words.count();
 }
 
+/* ----------------------------------------------------------------------
+   Return whether string is a valid integer number
+------------------------------------------------------------------------- */
+
+bool utils::is_integer(const std::string & str) {
+  if (str.size() == 0) {
+    return false;
+  }
+
+  for (auto c : str) {
+    if (isdigit(c) || c == '-' || c == '+') continue;
+    return false;
+  }
+  return true;
+}
+
+/* ----------------------------------------------------------------------
+   Return whether string is a valid floating-point number
+------------------------------------------------------------------------- */
+
+bool utils::is_double(const std::string & str) {
+  if (str.size() == 0) {
+    return false;
+  }
+
+  for (auto c : str) {
+    if (isdigit(c)) continue;
+    if (c == '-' || c == '+' || c == '.') continue;
+    if (c == 'e' || c == 'E') continue;
+    return false;
+  }
+  return true;
+}
+
 /* ------------------------------------------------------------------ */
 
 extern "C" {

src/utils.h

@@ -142,6 +142,20 @@ namespace LAMMPS_NS {
      * \return number of words found
      */
     size_t count_words(const std::string & text, const std::string & seperators = " \t\r\n\f");
+
+    /**
+     * \brief Check if string can be converted to valid integer
+     * \param text string that should be checked
+     * \return true, if string contains valid integer, false otherwise
+     */
+    bool is_integer(const std::string & str);
+
+    /**
+     * \brief Check if string can be converted to valid floating-point number
+     * \param text string that should be checked
+     * \return true, if string contains valid floating-point number, false otherwise
+     */
+    bool is_double(const std::string & str);
   }
 }
 

unittest/utils/test_utils.cpp

@@ -14,3 +14,39 @@ TEST(Utils, trim_comment) {
 TEST(Utils, count_words) {
     ASSERT_EQ(utils::count_words("some text # comment"), 2);
 }
+
+TEST(Utils, valid_integer) {
+    ASSERT_TRUE(utils::is_integer("10"));
+}
+
+TEST(Utils, valid_double) {
+    ASSERT_TRUE(utils::is_double("10.0"));
+}
+
+TEST(Utils, empty_not_an_integer) {
+    ASSERT_FALSE(utils::is_integer(""));
+}
+
+TEST(Utils, empty_not_a_double) {
+    ASSERT_FALSE(utils::is_double(""));
+}
+
+TEST(Utils, double_not_an_integer) {
+    ASSERT_FALSE(utils::is_integer("10.0"));
+}
+
+TEST(Utils, integer_is_double) {
+    ASSERT_TRUE(utils::is_double("10"));
+}
+
+TEST(Utils, is_double_with_exponential) {
+    ASSERT_TRUE(utils::is_double("10e22"));
+}
+
+TEST(Utils, is_double_with_neg_exponential) {
+    ASSERT_TRUE(utils::is_double("10e-22"));
+}
+
+TEST(Utils, signed_double_and_exponential) {
+    ASSERT_TRUE(utils::is_double("-10E-22"));
+}