Shell::readln now completes to a filename if the last word is a file (#…

…342)

* Shell::readln now completes to a filename if the last word is a file

- This allows situations like "./foo" to complete to a local directory
"./foobar"
- I'm not sure how efficient this is compared to the old competion, I'm
guessing not very.

* Have completion be relative to the current directory

* Remove random newline

src/shell/mod.rs

@@ -77,6 +77,7 @@ impl<'a> Shell<'a> {
             sigint_handle: ctrl_c
         }
     }
+
     fn readln(&mut self) -> Option<String> {
         let vars_ptr = &self.variables as *const Variables;
         let dirs_ptr = &self.directory_stack as *const DirectoryStack;
@@ -103,10 +104,17 @@ impl<'a> Shell<'a> {
                         CursorPosition::InSpace(None, _) => false,
                         CursorPosition::OnWordLeftEdge(index) => index >= 1,
                         CursorPosition::OnWordRightEdge(index) => {
-                            index >= 1 && !words.into_iter().nth(index).map(|(start, end)| {
-                                let buf = editor.current_buffer();
-                                buf.range(start, end).trim().starts_with('$')
-                            }).unwrap_or(false)
+                            if let Some((start, end)) = words.into_iter().nth(index) {
+                                if let Ok(mut file) = env::current_dir() {
+                                    let filename = editor.current_buffer().range(start, end);
+                                    file.push(filename);
+                                    file.exists() || file.parent().map(Path::exists).unwrap_or(false)
+                                } else {
+                                    false
+                                }
+                            } else {
+                                false
+                            }
                         }
                     };