Struct FSUtil 

pub struct FSUtil { /* private fields */ }

File system utility

The file system utility provides a set of functions to interact with the file system. This is designed with compatibility in mind. Not every platform that we target supports the standard Rust file system library. For example, WASM doesn’t support Rust file system functions in the stdlib.

Implementations

impl FSUtil

pub fn new( read_file: fn(path: &str) -> Option<String>, file_exists: fn(path: &str) -> bool, file_is_directory: fn(path: &str) -> bool, path_join: fn(base: &str, path: &str) -> String, parent_directory: fn(path: &str) -> String, path_is_absolute: fn(path: &str) -> bool, ) -> Self

Create a new instance of file system utility.

Arguments

• read_file - A function to read file content.
• file_exists - A function to check whether a file exists.
• file_is_directory - A function to check if file is a directory.
• path_join - A function to join base and path into a single path.
• parent_directory - A function to get the parent directory of the argument.

Examples

use teo_language_parser::fsutil::FSUtil;
use std::fs;
use std::path::{Path, PathBuf};

fn read_file(path: &str) -> Option<String> {
   match fs::read_to_string(Path::new(path)) {
      Ok(s) => Some(s),
     Err(_) => None,
  }
}

fn file_exists(path: &str) -> bool {
    Path::new(path).exists()
}

fn parent_directory(path: &str) -> String {
   let mut path = PathBuf::from(path);
   path.pop();
   path.to_str().unwrap().to_string()
}

fn path_is_absolute(path: &str) -> bool {
    path.starts_with("/")
}

fn path_join(base: &str, path: &str) -> String {
    format!("{}/{}", base, path)
}

fn file_is_directory(path: &str) -> bool {
    Path::new(path).is_dir()
}

let fs_util = FSUtil::new(
    read_file,
    file_exists,
    file_is_directory,
    path_join,
    parent_directory,
    path_is_absolute
);
assert!(fs_util.file_exists("Cargo.toml"));
assert!(!fs_util.file_is_directory("Cargo.toml"));
assert_eq!(fs_util.path_join("src", "main.rs"), "src/main.rs");
assert_eq!(fs_util.parent_directory("src/main.rs"), "src");
assert!(fs_util.path_is_absolute("/home/user"));

pub fn read_file(&self, path: &str) -> Option<String>

Read the file content from path into a String. None if file doesn’t exist or cannot be read.

pub fn file_exists(&self, path: &str) -> bool

Returns true if file exists at path.

pub fn file_is_directory(&self, path: &str) -> bool

Returns true if file at path is a directory.

pub fn path_join(&self, base: &str, path: &str) -> String

Returns a joined path of base and path.

pub fn parent_directory(&self, path: &str) -> String

Returns the parent directory of path.

pub fn path_is_absolute(&self, path: &str) -> bool

Returns true if path is an absolute path.

pub fn import_path(&self, source_path: &str, path: &str) -> String

Get the parent directory of source_path and join it with path.

Trait Implementations

impl Default for FSUtil

Provide a default implementation for file system utility.

fn default() -> Self

Returns the “default value” for a type.