Added alias resolution for PlantUML annotations

src/util/error.h

@@ -20,10 +20,18 @@
 #include <stdexcept>
 
 namespace clanguml::error {
+
 struct uml_alias_missing : public virtual std::runtime_error {
     uml_alias_missing(const std::string &message)
         : std::runtime_error(message)
     {
     }
 };
+
+struct substring_delimiter_not_found : public virtual std::runtime_error {
+    substring_delimiter_not_found(const std::string &message)
+        : std::runtime_error(message)
+    {
+    }
+};
 }

src/util/util.cc

@@ -19,6 +19,8 @@
 
 #include <spdlog/spdlog.h>
 
+#include <regex>
+
 namespace clanguml {
 namespace util {
 
@@ -101,5 +103,28 @@ std::string unqualify(const std::string &s)
 
     return fmt::format("{}", fmt::join(toks, " "));
 }
+
+bool find_element_alias(
+    const std::string &input, std::tuple<std::string, size_t, size_t> &result)
+{
+
+    std::regex alias_regex("(@A\\([^\\).]+\\))");
+
+    auto alias_it =
+        std::sregex_iterator(input.begin(), input.end(), alias_regex);
+    auto end_it = std::sregex_iterator();
+
+    if (alias_it == end_it)
+        return false;
+
+    std::smatch match = *alias_it;
+    std::string alias = match.str().substr(3, match.str().size() - 4);
+
+    std::get<0>(result) = alias;
+    std::get<1>(result) = match.position();
+    std::get<2>(result) = match.length();
+
+    return true;
+}
 }
 }

src/util/util.h

@@ -91,5 +91,18 @@ std::string ns_relative(
  * @return Unqualified type spelling.
  */
 std::string unqualify(const std::string &s);
+
+/**
+ * @brief Find element alias in Puml note
+ *
+ * Finds aliases of the form @A(entity_name) in the Puml notes
+ * or directives.
+ * The match, if any, is returned in the result tuple:
+ *   (entity_name, offset, length)
+ *
+ * @return True if match was found
+ */
+bool find_element_alias(
+    const std::string &input, std::tuple<std::string, size_t, size_t> &result);
 }
 }