Add some prerequisites

src/symbols/dir.rs

@@ -0,0 +1,49 @@
+use std::borrow::Cow;
+use std::error::Error;
+use std::fmt;
+use std::fs;
+use std::io;
+use std::io::{Read, Write};
+use std::ops::Deref;
+use std::path::Path;
+
+use symbols::Symbol;
+
+pub struct Dir<D> where D: AsRef<str> + fmt::Display {
+  path: D
+}
+
+impl<D> Dir<D> where D: AsRef<str> + fmt::Display {
+  pub fn new(path: D) -> Self {
+    Dir { path: path }
+  }
+}
+
+impl<D> Symbol for Dir<D> where D: AsRef<str> + fmt::Display {
+  fn target_reached(&self) -> Result<bool, Box<Error>> {
+    let metadata = fs::metadata(self.path.as_ref());
+    // Check if dir exists
+    if let Err(e) = metadata {
+      return if e.kind() == io::ErrorKind::NotFound {
+        Ok(false)
+      } else {
+        Err(Box::new(e))
+      };
+    }
+    if metadata.unwrap().is_dir() {
+      Ok(true)
+    } else {
+      Err(Box::new(io::Error::new(io::ErrorKind::AlreadyExists, "Could not create a directory, non-directory file exists")))
+    }
+  }
+
+  fn execute(&self) -> Result<(), Box<Error>> {
+    fs::create_dir_all(self.path.as_ref()).map_err(|e| Box::new(e) as Box<Error>)
+  }
+}
+
+impl<D> fmt::Display for Dir<D> where D: AsRef<str> + fmt::Display {
+  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error>{
+    write!(f, "Dir {}", self.path)
+  }
+}