better support Path and str in parse_file args

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Argument to `parse_file` is changed to `AsRef<Path>`
 
 ## [0.1.0] - 2020-02-02
 ### Added

README.md

@@ -4,7 +4,7 @@ A library in Rust to parse a Verilog Filelist and return
 a list of files, include directories and defines.
 
 Environment variables represented with paranthesis or 
-curly braces (i.e. $() or ${}) will be automatically
+curly braces (i.e. `$()` or `${}`) will be automatically
 substituted.
 
 # Example

src/file_parser.rs

@@ -2,7 +2,7 @@ use regex::Regex;
 use std::collections::HashMap;
 use std::error::Error;
 use std::fs;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use crate::line_parser;
 use crate::line_parser::LineType;
@@ -49,15 +49,16 @@ impl Filelist {
 /// Environment variables represented with paranthesis or 
 /// curly braces (i.e. `$()` or `${}`) will be automatically
 /// substituted.
+/// 
 /// # Arguments
 ///
-/// * `path` - A string slice that is the path to the filelist
+/// * `path` - The path to the filelist
 ///
 /// # Errors
 ///
 /// Returns an error if the filelist in `path` cannot be read. Also returns
 /// error if any of the nested filelists cannot be read.
-pub fn parse_file(path: &str) -> Result<Filelist, Box<dyn Error>> {
+pub fn parse_file(path: impl AsRef<Path>) -> Result<Filelist, Box<dyn Error>> {
     let contents = fs::read_to_string(path)?;
 
     let mut filelist = Filelist::new();