lib/cli: finish initial implementation

This should be all functionality that is needed for now.
The next step is building unit tests to check that everything works correctly.

Who am I kidding? There will most certainly be bugs in there given that this
code has been typed out without ever being run.

src/lib/cli.cpp

@@ -56,6 +56,7 @@ namespace CLI {
     ArgumentsParser::ArgumentsParser(int argc, char* argv[], std::vector<Flag> flags, std::vector<UnpositionalArgument> unpositionalArguments, std::vector<PositionalArgument> positionalArguments) {
         this->wrongUsage = false;
         this->wrongUsageMessages = std::vector<std::string>();
+        this->programName = std::string(argv[0]);
         this->positionalArguments = positionalArguments;
         // create lookup tables for all flags and unpositional arguments
         // by their names
@@ -78,7 +79,7 @@ namespace CLI {
 
         UnpositionalArgument* argumentWaitingForValue = nullptr;
         std::vector<CLI::PositionalArgument>::size_type positionalArgumentCounter = 0;
-        for (int i=0; i<argc; i++) {
+        for (int i=1; i<argc; i++) {
             std::string argument(argv[i]);
             if (argument[0]=='-') {
                 // do we have unfinished business?
@@ -189,4 +190,58 @@ namespace CLI {
         }
     }
 
+    ErrorOr<std::string> ArgumentsParser::getProgramName() {
+        if (this->wrongUsage) {
+            return ErrorOr<std::string>(true, ErrorCodes::WRONG_USAGE, this->programName);
+        }
+        return ErrorOr<std::string>(this->programName);
+    }
+
+    ErrorOr<bool> ArgumentsParser::getFlag(int argc, char* argv[], char shortName) {
+        if (!this->flagsByShortName.contains(shortName)) return ErrorOr<bool>(true, ErrorCodes::UNKNOWN_KEY, false);
+        if (this->wrongUsage) {
+            return ErrorOr<bool>(true, ErrorCodes::WRONG_USAGE, this->flagsByShortName[shortName]->present);
+        }
+        return ErrorOr<bool>(this->flagsByShortName[shortName]->present);
+    }
+
+    ErrorOr<bool> ArgumentsParser::getFlag(int argc, char* argv[], std::string longName) {
+        if (!this->flagsByLongName.contains(longName)) return ErrorOr<bool>(true, ErrorCodes::UNKNOWN_KEY, false);
+        if (this->wrongUsage) {
+            return ErrorOr<bool>(true, ErrorCodes::WRONG_USAGE, this->flagsByLongName[longName]->present);
+        }
+        return ErrorOr<bool>(this->flagsByLongName[longName]->present);
+    }
+
+    ErrorOr<std::string> ArgumentsParser::getPositionalArgument(int argc, char* argv[], std::vector<CLI::PositionalArgument>::size_type position){
+        if (position >= this->positionalArguments.size()) return ErrorOr<std::string>(true, ErrorCodes::OUT_OF_RANGE, std::string(""));
+        if (this->wrongUsage) {
+            if (this->positionalArguments.at(position).present) return ErrorOr<std::string>(true, ErrorCodes::WRONG_USAGE, this->positionalArguments.at(position).value);
+            else return ErrorOr<std::string>(true, ErrorCodes::NOT_PRESENT, std::string(""));
+        }
+        return ErrorOr<std::string>(this->positionalArguments.at(position).value);
+    }
+
+    ErrorOr<std::string> ArgumentsParser::getUnpositionalArgument(int argc, char* argv[], char shortName) {
+        if (!this->argumentsByShortName.contains(shortName)) return ErrorOr<std::string>(true, ErrorCodes::UNKNOWN_KEY, std::string(""));
+        if (this-wrongUsage) {
+            if (this->argumentsByShortName[shortName]->present) return ErrorOr<std::string>(true, ErrorCodes::WRONG_USAGE, this->argumentsByShortName[shortName]->value);
+            else return ErrorOr<std::string>(true, ErrorCodes::NOT_PRESENT, std::string(""));
+        }
+        if (this->argumentsByShortName[shortName]->present) return ErrorOr<std::string>(this->argumentsByShortName[shortName]->value);
+        // argument is not present, but this is not an error -> false, NOT_PRESENT, ""
+        else return ErrorOr<std::string>(false, ErrorCodes::NOT_PRESENT, std::string(""));
+    }
+
+    ErrorOr<std::string> ArgumentsParser::getUnpositionalArgument(int argc, char* argv[], std::string longName) {
+        if (!this->argumentsByLongName.contains(longName)) return ErrorOr<std::string>(true, ErrorCodes::UNKNOWN_KEY, std::string(""));
+        if (this-wrongUsage) {
+            if (this->argumentsByLongName[longName]->present) return ErrorOr<std::string>(true, ErrorCodes::WRONG_USAGE, this->argumentsByLongName[longName]->value);
+            else return ErrorOr<std::string>(true, ErrorCodes::NOT_PRESENT, std::string(""));
+        }
+        if (this->argumentsByLongName[longName]->present) return ErrorOr<std::string>(this->argumentsByLongName[longName]->value);
+        // argument is not present, but this is not an error -> false, NOT_PRESENT, ""
+        else return ErrorOr<std::string>(false, ErrorCodes::NOT_PRESENT, std::string(""));
+    }
+    //std::string ArgumentsParser::getUsage();
 }

src/lib/cli.h++

@@ -77,11 +77,11 @@ namespace CLI {
         ~ArgumentsParser();
 
         ErrorOr<std::string> getProgramName();
-        ErrorOr<bool> getFlag(int argc, char* argv, char shortName);
+        ErrorOr<bool> getFlag(int argc, char* argv[], char shortName);
-        ErrorOr<bool> getFlag(int argc, char* argv, std::string longName);
+        ErrorOr<bool> getFlag(int argc, char* argv[], std::string longName);
-        ErrorOr<std::string> getPositionalArgument(int argc, char* argv, int position);
+        ErrorOr<std::string> getPositionalArgument(int argc, char* argv[], std::vector<CLI::PositionalArgument>::size_type position);
-        ErrorOr<std::string> getUnpositionalArgument(int argc, char* argv, char shortName);
+        ErrorOr<std::string> getUnpositionalArgument(int argc, char* argv[], char shortName);
-        ErrorOr<std::string> getUnpositionalArgument(int argc, char* argv, std::string longName);
+        ErrorOr<std::string> getUnpositionalArgument(int argc, char* argv[], std::string longName);
 
         std::string getUsage();
     };

src/lib/error.h++

@@ -75,6 +75,9 @@ namespace ErrorCodes {
 
     const uint8_t WRONG_USAGE = 4;
 
+    // when dealing with maps
+    const uint8_t UNKNOWN_KEY = 5;
+
     const uint8_t UNIMPLEMENTED = 254;
 
     const uint8_t UNKNOWN = 255;