Add style_for_path_components function

closes #5

src/bin.rs

@@ -1,7 +1,6 @@
 use std::alloc::System;
 use std::io;
 use std::io::prelude::*;
-use std::path::Path;
 
 use lscolors::{LsColors, Style};
 
@@ -22,11 +21,12 @@ fn run() -> io::Result<()> {
         }
 
         let path_str = String::from_utf8_lossy(&buf[..(buf.len() - 1)]);
-        let path = Path::new(path_str.as_ref());
-        let style = ls_colors.style_for_path(path);
-        let ansi_style = style.map(Style::to_ansi_term_style).unwrap_or_default();
 
-        writeln!(stdout, "{}", ansi_style.paint(path_str))?;
+        for (component, style) in ls_colors.style_for_path_components(path_str.as_ref()) {
+            let ansi_style = style.map(Style::to_ansi_term_style).unwrap_or_default();
+            write!(stdout, "{}", ansi_style.paint(component.to_string_lossy()))?;
+        }
+        writeln!(stdout)?;
 
         buf.clear();
     }

src/lib.rs

@@ -18,7 +18,8 @@ mod fs;
 pub mod style;
 
 use std::env;
-use std::path::Path;
+use std::ffi::OsString;
+use std::path::{Component, Path, PathBuf, MAIN_SEPARATOR};
 
 pub use crate::style::{Color, FontStyle, Style};
 
@@ -180,6 +181,45 @@ impl LsColors {
 
         None
     }
+
+    /// Get ANSI styles for each component of a given path. Components already
+    /// include the patj separator symbol, if required. For a path like
+    /// `foo/bar/test.md`, this would return three pairs for the components
+    /// `foo/`, `bar/` and `test.md` together with their respective styles.
+    pub fn style_for_path_components<P: AsRef<Path>>(
+        &self,
+        path: P,
+    ) -> Vec<(OsString, Option<&Style>)> {
+        let mut styled_components = vec![];
+
+        // Full path to the current component.
+        let mut component_path = PathBuf::new();
+
+        // Traverse the path and colorize each component
+        let mut components = path.as_ref().components().peekable();
+        while let Some(component) = components.next() {
+            let mut component_str = component.as_os_str().to_os_string();
+
+            component_path.push(&component_str);
+            let style = self.style_for_path(&component_path);
+
+            if components.peek().is_some() {
+                match component {
+                    // Prefix needs no separator, as it is always followed by RootDir.
+                    // RootDir is already a separator.
+                    Component::Prefix(_) | Component::RootDir => {}
+                    // Everything else uses a separator that is painted the same way as the component.
+                    Component::CurDir | Component::ParentDir | Component::Normal(_) => {
+                        component_str.push(MAIN_SEPARATOR.to_string());
+                    }
+                }
+            }
+
+            styled_components.push((component_str, style));
+        }
+
+        styled_components
+    }
 }
 
 #[cfg(test)]