Emit all output to custom stdio channels

This change continues and concludes the effort of using customizable
stdio channels for output of data from the program. It does so by
replacing the standard println macro with a custom one that outputs the
data to the supplied context's stdout object.
Because this object is injected from the main function, it will be
possible for tests invoking this function to supply custom Write objects
that can buffer this data and make it available for verification
purposes.

1 files changed, 38 insertions, 0 deletions

diff --git a/nitrocli/src/redefine.rs b/nitrocli/src/redefine.rs
new file mode 100644
index 0000000..a79cb4b
--- /dev/null
+++ b/nitrocli/src/redefine.rs
@@ -0,0 +1,38 @@
+// redefine.rs
+
+// *************************************************************************
+// * Copyright (C) 2019 Daniel Mueller (deso@posteo.net)                   *
+// *                                                                       *
+// * This program is free software: you can redistribute it and/or modify  *
+// * it under the terms of the GNU General Public License as published by  *
+// * the Free Software Foundation, either version 3 of the License, or     *
+// * (at your option) any later version.                                   *
+// *                                                                       *
+// * This program is distributed in the hope that it will be useful,       *
+// * but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+// * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+// * GNU General Public License for more details.                          *
+// *                                                                       *
+// * You should have received a copy of the GNU General Public License     *
+// * along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+// *************************************************************************
+
+// A replacement of the standard println!() macro that requires an
+// execution context as the first argument and prints to its stdout.
+macro_rules! println {
+  ($ctx:expr) => {
+    writeln!($ctx.stdout, "")
+  };
+  ($ctx:expr, $($arg:tt)*) => {
+    writeln!($ctx.stdout, $($arg)*)
+  };
+}
+
+macro_rules! eprintln {
+  ($ctx:expr) => {
+    writeln!($ctx.stderr, "")
+  };
+  ($ctx:expr, $($arg:tt)*) => {
+    writeln!($ctx.stderr, $($arg)*)
+  };
+}