Add optional colour to the logging helper prefixes

Author: stuarthayhurst

src/ammonite/utils/debug.cpp

@@ -10,7 +10,8 @@
 #ifdef AMMONITE_DEBUG
 /*NOLINTBEGIN(cppcoreguidelines-avoid-non-const-global-variables,
               cppcoreguidelines-interfaces-global-init)*/
-ammonite::utils::OutputHelper ammoniteInternalDebug(std::cout, "DEBUG: ");
+ammonite::utils::OutputHelper ammoniteInternalDebug(std::cout, "DEBUG: ",
+                                                    ammonite::utils::colour::magenta);
 /*NOLINTEND(cppcoreguidelines-avoid-non-const-global-variables,
             cppcoreguidelines-interfaces-global-init)*/
 #endif

src/ammonite/utils/logging.cpp

@@ -9,11 +9,16 @@ namespace ammonite {
   namespace utils {
     namespace {
       std::mutex outputLock;
+
+      const std::string reset = "\033[0m";
     }
 
     OutputHelper::OutputHelper(std::ostream& output, const std::string& pre):
       outputStream(output), prefix(pre) {}
 
+    OutputHelper::OutputHelper(std::ostream& output, const std::string& pre, const std::string& colour):
+      outputStream(output), prefix(colour + pre + reset) {}
+
     //Output the stored string
     OutputHelper& OutputHelper::operator << (std::ostream& (*)(std::ostream&)) {
       //Safely output the prefix, buffered string and new line
@@ -32,9 +37,9 @@ namespace ammonite {
                   cppcoreguidelines-interfaces-global-init)*/
     thread_local std::stringstream OutputHelper::storageStream = std::stringstream("");
 
-    OutputHelper error(std::cerr, "ERROR: ");
-    OutputHelper warning(std::cerr, "WARNING: ");
-    OutputHelper status(std::cout, "STATUS: ");
+    OutputHelper error(std::cerr, "ERROR: ", colour::red);
+    OutputHelper warning(std::cerr, "WARNING: ", colour::yellow);
+    OutputHelper status(std::cout, "STATUS: ", colour::green);
     /*NOLINTEND(cppcoreguidelines-avoid-non-const-global-variables,
                 cppcoreguidelines-interfaces-global-init)*/
   }

src/include/ammonite/utils/logging.hpp

@@ -8,10 +8,22 @@
 
 namespace ammonite {
   namespace utils {
+    namespace colour {
+      const std::string black = "\033[30m";
+      const std::string red = "\033[31m";
+      const std::string green = "\033[32m";
+      const std::string yellow = "\033[33m";
+      const std::string blue = "\033[34m";
+      const std::string magenta = "\033[35m";
+      const std::string cyan = "\033[36m";
+      const std::string white = "\033[37m";
+    }
+
     /*
      - Output helper to buffer output data and synchronise with other helpers to display
      - Prefixes the output with the prefix of the instant used to flush
      - Buffer is shared between all instances on the same thread
+     - Colour is only used for the prefix
     */
     class OutputHelper {
     private:
@@ -23,6 +35,7 @@ namespace ammonite {
 
     public:
       OutputHelper(std::ostream& output, const std::string& pre);
+      OutputHelper(std::ostream& output, const std::string& pre, const std::string& colour);
       template<typename T> OutputHelper& operator << (T&& input);
       OutputHelper& operator << (std::ostream& (*)(std::ostream&));
     };