Add optional color and style support using paris crate

More info about formatting:
https://github.com/0x20F/paris

When enabled you can use formatting like this:
info!("I can write <b>bold</b> text or use tags to <red>color it</>");

Cargo.toml

@@ -25,4 +25,5 @@ default = ["termcolor"]
 [dependencies]
 log = { version = "0.4.*", features = ["std"] }
 termcolor = { version = "1.1.*", optional = true }
+paris = { version = "*", optional = true }
 chrono = "0.4.1"

README.md

@@ -61,6 +61,24 @@ simplelog = "^0.10.0"
 ```
 to your `Cargo.toml`
 
+## Color and style support
+
+This crate can use a [paris](https://github.com/0x20F/paris) crate to provide support for color and styles.
+To use this feature you need to set a paris feature, like this:
+```
+[dependencies]
+simplelog = { version = "^0.10.0", features = ["paris"] }
+```
+in your `Cargo.toml`
+
+After this you can use e.g. the following call:
+```rust
+info!("I can write <b>bold</b> text or use tags to <red>color it</>");
+```
+
+This will automatically generates ANSI terminal control sequences for required features.
+More formatting info: [paris crate documentation](https://github.com/0x20F/paris)
+
 ## [Documentation](https://docs.rs/simplelog/)
 
 ## Contributing

src/lib.rs

@@ -39,6 +39,9 @@ use log::Log;
 #[cfg(test)]
 use log::*;
 
+#[cfg(feature = "paris")]
+mod paris;
+
 /// Trait to have a common interface to obtain the Level of Loggers
 ///
 /// Necessary for CombinedLogger to calculate

src/paris/mod.rs

@@ -0,0 +1,39 @@
+#[allow(missing_docs)]
+#[macro_export]
+macro_rules! info {
+    ($($args:tt)+) => {
+        log::info!("{}", paris::formatter::colorize_string(format!($($args)*)));
+    };
+}
+
+#[allow(missing_docs)]
+#[macro_export]
+macro_rules! debug {
+    ($($args:tt)+) => {
+        log::debug!("{}", paris::formatter::colorize_string(format!($($args)*)));
+    };
+}
+
+#[allow(missing_docs)]
+#[macro_export]
+macro_rules! trace {
+    ($($args:tt)+) => {
+        log::trace!("{}", paris::formatter::colorize_string(format!($($args)*)));
+    };
+}
+
+#[allow(missing_docs)]
+#[macro_export]
+macro_rules! warn {
+    ($($args:tt)+) => {
+        log::warn!("{}", paris::formatter::colorize_string(format!($($args)*)));
+    };
+}
+
+#[allow(missing_docs)]
+#[macro_export]
+macro_rules! error {
+    ($($args:tt)+) => {
+        log::error!("{}", paris::formatter::colorize_string(format!($($args)*)));
+    };
+}