Color exceptions (#1698)

1 files changed, 69 insertions, 0 deletions

diff --git a/src/ansi.rs b/src/ansi.rs
new file mode 100644
index 000000000..47bf6c941
--- /dev/null
+++ b/src/ansi.rs
@@ -0,0 +1,69 @@
+use ansi_term::Color::Cyan;
+use ansi_term::Color::Red;
+use ansi_term::Color::Yellow;
+use ansi_term::Style;
+use regex::Regex;
+use std::borrow::Cow;
+use std::env;
+use std::fmt;
+
+lazy_static! {
+  // STRIP_ANSI_RE and strip_ansi_codes are lifted from the "console" crate.
+  // Copyright 2017 Armin Ronacher <armin.ronacher@active-4.com>. MIT License.
+  static ref STRIP_ANSI_RE: Regex = Regex::new(
+    r"[\x1b\x9b][\[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-PRZcf-nqry=><]"
+  ).unwrap();
+  static ref NO_COLOR: bool = {
+    env::var_os("NO_COLOR").is_some()
+  };
+}
+
+/// Helper function to strip ansi codes.
+#[allow(dead_code)]
+pub fn strip_ansi_codes(s: &str) -> Cow<str> {
+  STRIP_ANSI_RE.replace_all(s, "")
+}
+
+pub fn use_color() -> bool {
+  *NO_COLOR == false
+}
+
+pub fn red_bold(s: String) -> impl fmt::Display {
+  let mut style = Style::new();
+  if use_color() {
+    style = style.bold().fg(Red);
+  }
+  style.paint(s)
+}
+
+pub fn italic_bold(s: String) -> impl fmt::Display {
+  let mut style = Style::new();
+  if use_color() {
+    style = style.italic().bold();
+  }
+  style.paint(s)
+}
+
+pub fn yellow(s: String) -> impl fmt::Display {
+  let mut style = Style::new();
+  if use_color() {
+    style = style.fg(Yellow);
+  }
+  style.paint(s)
+}
+
+pub fn cyan(s: String) -> impl fmt::Display {
+  let mut style = Style::new();
+  if use_color() {
+    style = style.fg(Cyan);
+  }
+  style.paint(s)
+}
+
+pub fn bold(s: String) -> impl fmt::Display {
+  let mut style = Style::new();
+  if use_color() {
+    style = style.bold();
+  }
+  style.paint(s)
+}