2 files changed, 113 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..e0386ab
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,76 @@
+mod log_level;
+pub use log_level::*;
+
+use std::sync::Mutex;
+
+
+pub const NORMAL: &str = "\x1b[0m";
+pub const BOLD:   &str = "\x1b[1m";
+pub const WHITE:  &str = "\x1b[37m";
+pub const RED:    &str = "\x1b[31m";
+pub const YELLOW: &str = "\x1b[33m";
+pub const BLUE:   &str = "\x1b[34m";
+
+
+pub static LOG_LEVEL: Mutex<LogLevel> = Mutex::new(LogLevel::Warn);
+
+pub fn set_log_level(level: LogLevel) {
+    *LOG_LEVEL.lock().unwrap() = level;
+}
+
+pub fn get_log_level() -> LogLevel {
+    *LOG_LEVEL.lock().unwrap()
+}
+
+
+#[macro_export] macro_rules! info {
+    ($($tokens:tt)*) => {
+        if *$crate::LOG_LEVEL.lock().unwrap() <= { LogLevel::Info } {
+            eprint!("{}{}[INFO]{}: ",
+                $crate::BOLD,
+                $crate::BLUE,
+                $crate::NORMAL,
+            );
+            eprint!($($tokens)*);
+            eprintln!("{}",
+                $crate::NORMAL,
+            );
+        }
+    };
+}
+
+#[macro_export] macro_rules! warn {
+    ($($tokens:tt)*) => {{
+        if *$crate::LOG_LEVEL.lock().unwrap() <= { LogLevel::Warn } {
+            eprint!("{}{}[WARNING]{}{}: ",
+                $crate::BOLD,
+                $crate::YELLOW,
+                $crate::NORMAL,
+                $crate::WHITE,
+            );
+            eprint!($($tokens)*);
+            eprintln!("{}",
+                $crate::NORMAL,
+            );
+        }
+    }};
+}
+
+#[macro_export] macro_rules! error {
+    ($($tokens:tt)*) => {{
+        if *$crate::LOG_LEVEL.lock().unwrap() <= { LogLevel::Error } {
+            eprint!("{}{}[ERROR]{}: ",
+                $crate::BOLD,
+                $crate::RED,
+                $crate::WHITE,
+
+            );
+            eprint!($($tokens)*);
+            eprintln!("{}",
+                $crate::NORMAL,
+            );
+        }
+        std::process::exit(1);
+    }};
+}
+
diff --git a/src/log_level.rs b/src/log_level.rs
new file mode 100644
index 0000000..6c84cb0
--- /dev/null
+++ b/src/log_level.rs
@@ -0,0 +1,37 @@
+
+use std::cmp::Ordering;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum LogLevel {
+    /// Verbose record of decisions and operations.
+    Info,
+    /// Report recoverable issues.
+    Warn,
+    /// Report unrecoverable errors and quit.
+    Error,
+}
+
+impl PartialOrd for LogLevel {
+    fn partial_cmp(&self, other: &LogLevel) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for LogLevel {
+    fn cmp(&self, other: &LogLevel) -> Ordering {
+        use LogLevel::*;
+        match (self, other) {
+            (Info , Info ) => Ordering::Equal,
+            (Info , Warn ) => Ordering::Less,
+            (Info , Error) => Ordering::Less,
+
+            (Warn , Info ) => Ordering::Greater,
+            (Warn , Warn ) => Ordering::Equal,
+            (Warn , Error) => Ordering::Less,
+
+            (Error , Info ) => Ordering::Greater,
+            (Error , Warn ) => Ordering::Greater,
+            (Error , Error) => Ordering::Equal,
+        }
+    }
+}