improved argument parser

application/argumentparser.cpp

@@ -1,5 +1,6 @@
 #include "argumentparser.h"
 #include "failure.h"
+
 #include "../conversion/stringconversion.h"
 #include "../misc/random.h"
 
@@ -38,6 +39,7 @@ Argument::Argument(const std::string &name, const std::string abbreviation, cons
     m_required(false),
     m_combinable(false),
     m_implicit(false),
+    m_denotesOperation(false),
     m_requiredValueCount(0),
     m_default(false),
     m_present(false),
@@ -451,7 +453,21 @@ void ArgumentParser::parseArgs(int argc, char *argv[])
                 } else {
                     readValue:
                     if(!currentArg) {
-                        // we have not parsed an argument before -> check if there's an implicit argument definition
+                        // we have not parsed an argument before
+                        // -> check if an argument which denotes the operation is specified
+                        if(i == argv + 1) {
+                            for(Argument *arg : m_mainArgs) {
+                                if(!arg->isPresent() && arg->denotesOperation()
+                                        && (arg->name() == givenArg || arg->abbreviation() == givenArg)) {
+                                    currentArg = arg;
+                                    break;
+                                }
+                            }
+                            if(currentArg) {
+                                continue;
+                            }
+                        }
+                        // -> check if there's an implicit argument definition
                         for(Argument *arg : m_mainArgs) {
                             if(!arg->isPresent() && arg->isImplicit()) {
                                 // set present flag of argument

application/argumentparser.h

@@ -63,6 +63,8 @@ public:
     void setCombinable(bool value);
     bool isImplicit() const;
     void setImplicit(bool value);
+    bool denotesOperation() const;
+    void setDenotesOperation(bool denotesOperation);
     void setCallback(CallbackFunction callback);
     void printInfo(std::ostream &os, unsigned char indentionLevel = 0) const;
     const ArgumentVector &secondaryArguments() const;
@@ -81,6 +83,7 @@ private:
     bool m_required;
     bool m_combinable;
     bool m_implicit;
+    bool m_denotesOperation;
     int m_requiredValueCount;
     StringList m_valueNames;
     bool m_default;
@@ -415,6 +418,8 @@ inline void Argument::setCombinable(bool value)
 /*!
  * \brief Returns an indication whether the argument can be specified implicitely.
  *
+ * An implicit main argument is assumed to be present even if only its value is present.
+ *
  * \sa setImplicit()
  */
 inline bool Argument::isImplicit() const
@@ -432,6 +437,30 @@ inline void Argument::setImplicit(bool value)
     m_implicit = value;
 }
 
+/*!
+ * \brief Returns whether the argument denotes the operation.
+ *
+ * An argument which denotes the operation might be specified
+ * withouth "--" or "-" prefix as first main argument.
+ *
+ * The default value is false.
+ *
+ * \sa setDenotesOperation()
+ */
+inline bool Argument::denotesOperation() const
+{
+    return m_denotesOperation;
+}
+
+/*!
+ * \brief Sets whether the argument denotes the operation.
+ * \sa denotesOperation()
+ */
+inline void Argument::setDenotesOperation(bool denotesOperation)
+{
+    m_denotesOperation = denotesOperation;
+}
+
 /*!
  * \brief Sets a \a callback function which will be called by the parser if
  *        the argument could be found and no parsing errors occured.