Use global option for verbosity in R package and add tests.

src/mlpack/bindings/R/mlpack/tests/testthat/test-R_binding.R

@@ -335,3 +335,25 @@ test_that("TestReallyNotVerbose", {
                                build_model=TRUE,
                                verbose=FALSE))
 })
+
+# Make sure that the mlpack verbose global option does anything at all.
+test_that("TestGlobalVerbose", {
+  options(mlpack.verbose = TRUE)
+  expect_output(test_r_binding(4.0, 12, "hello",
+                               build_model=TRUE))
+})
+
+# Test that we get no output when the global verbose option is set to false.
+test_that("TestGlobalNotVerbose", {
+  options(mlpack.verbose = FALSE)
+  expect_silent(test_r_binding(4.0, 12, "hello",
+                               build_model=TRUE))
+})
+
+# Test that we can override the global verbose option.
+test_that("TestGlobalVerboseOverride", {
+  options(mlpack.verbose = TRUE)
+  expect_silent(test_r_binding(4.0, 12, "hello",
+                               build_model=TRUE,
+                               verbose=FALSE))
+})

src/mlpack/bindings/R/print_input_param.hpp

@@ -30,9 +30,22 @@ void PrintInputParam(util::ParamData& d,
 {
   MLPACK_COUT_STREAM << d.name;
   if (std::is_same<T, bool>::value)
-    MLPACK_COUT_STREAM << "=FALSE";
+  {
+    if (d.name == "verbose")
+    {
+      // Make sure that we use the global verbose option for the mlpack package
+      // as the default.
+      MLPACK_COUT_STREAM << "=getOption(\"mlpack.verbose\", FALSE)";
+    }
+    else
+    {
+      MLPACK_COUT_STREAM << "=FALSE";
+    }
+  }
   else if (!d.required)
+  {
     MLPACK_COUT_STREAM << "=NA";
+  }
 }
 
 } // namespace r