Cargo : 0.5.0 -> 0.6.0

Cargo.lock

@@ -4,4 +4,4 @@ version = 3
 
 [[package]]
 name = "rash"
-version = "0.5.0"
+version = "0.6.0"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rash"
-version = "0.5.0"
+version = "0.6.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

README.md

@@ -12,6 +12,7 @@ I want to learn Rust and see how much effort I can put into making an interopera
 - [ ] Environment variables
 - [ ] Builtins
   - [x] `cd`
+  - [x] `:`
   - [ ] `set`
   - [ ] `alias`
   - [ ] `type`
@@ -19,3 +20,4 @@ I want to learn Rust and see how much effort I can put into making an interopera
 - [ ] PS1
 - [ ] Execute code from a file
 - [ ] Clean error handling
+- [ ] Override Ctrl-C

src/command/builtins.rs

@@ -1,4 +1,6 @@
-use crate::{error::print_error, exit_code::ExitCode};
+use crate::error;
+use crate::error::CdError;
+use crate::exit_code::ExitCode;
 
 use std::env;
 use std::{env::set_current_dir, path::PathBuf};
@@ -17,18 +19,20 @@ pub(super) fn cd(args: &Vec<String>) -> ExitCode {
 
     let exit_code: ExitCode;
     if path.is_some() {
-        exit_code = match set_current_dir(path.unwrap()) {
-            Ok(()) => ExitCode::success(),
-            Err(_e) => ExitCode::new(2),
-        };
+        let path = path.unwrap();
+        let result = set_current_dir(&path);
+
+        if result.is_err() {
+            let error = CdError::new(&args[0]);
+            error::print(Box::new(error));
+            exit_code = ExitCode::new(2);
+        } else {
+            exit_code = ExitCode::success();
+        }
     } else {
         exit_code = ExitCode::success();
     }
 
-    if exit_code.get() != 0 {
-        print_error("lol");
-    }
-
     exit_code
 }
 

src/command/mod.rs

@@ -2,7 +2,8 @@ mod builtins;
 pub mod command_builder;
 pub mod command_sequence;
 
-use crate::error::print_error;
+use crate::error;
+use crate::error::CommandNotFoundError;
 use crate::exit_code::ExitCode;
 
 type BuiltinFunction = fn(&Vec<String>) -> ExitCode;
@@ -81,20 +82,9 @@ impl Command for UnixProgram {
 
             exit_code
         } else {
-            let message = format!(
-                "{}: command not found",
-                self.command.get_program().to_str().unwrap()
-            );
-            print_error(message.as_str());
+            let error = CommandNotFoundError::new(self.command.get_program().to_str().unwrap());
+            error::print(Box::new(error));
             ExitCode::not_found()
         }
     }
 }
-
-struct Nothing;
-
-impl Command for Nothing {
-    fn spawn(&mut self) -> ExitCode {
-        ExitCode::success()
-    }
-}

src/control.rs

@@ -1,7 +1,8 @@
 use crate::command::Command;
 use crate::exit_code::ExitCode;
-use crate::interface::{get_user_input, print_prompt};
+use crate::interface::get_user_input;
 use crate::parser::parse;
+use crate::variables::Variables;
 
 fn exit(code: &ExitCode) {
     let code = i32::from(code.get());
@@ -11,13 +12,13 @@ fn exit(code: &ExitCode) {
 
 pub fn run() {
     let mut current_exit_code = ExitCode::new(0);
+    let mut variables = Variables::new();
 
     loop {
-        print_prompt();
         let user_input = get_user_input();
 
         if user_input.is_some() {
-            let mut command_sequence = parse(user_input.unwrap());
+            let mut command_sequence = parse(user_input.unwrap(), &variables);
 
             if !command_sequence.is_empty() {
                 current_exit_code = command_sequence.spawn();

src/error.rs

@@ -1,9 +1,59 @@
 use std::env;
+use std::fmt;
+use std::fmt::{Display, Formatter};
 use std::path::Path;
 
-pub fn print_error(message: &str) {
+type Error = Box<dyn Display>;
+
+pub struct CdError {
+    entry_name: String,
+}
+
+impl CdError {
+    pub fn new(entry_name: &str) -> Self {
+        Self {
+            entry_name: String::from(entry_name),
+        }
+    }
+}
+
+impl Display for CdError {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "cd: no such directory as '{}'", self.entry_name)
+    }
+}
+
+pub struct CommandNotFoundError {
+    command: String,
+}
+
+impl CommandNotFoundError {
+    pub fn new(command: &str) -> Self {
+        Self {
+            command: String::from(command),
+        }
+    }
+}
+
+impl Display for CommandNotFoundError {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}: command not found", self.command)
+    }
+}
+
+pub struct UnmatchedQuoteError {
+    index: usize,
+}
+
+impl Display for UnmatchedQuoteError {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "unmatched quote at character {}", self.index)
+    }
+}
+
+pub fn print(error: Error) {
     let name = env::args().next().unwrap_or(String::from("rash"));
     let name = Path::new(&name).file_name().unwrap().to_str().unwrap();
 
-    eprintln!("{}: {}", name, message);
+    eprintln!("{}: {}", name, error);
 }

src/interface.rs

@@ -1,21 +1,22 @@
 use std::io::Write;
 use std::io::{stdin, stdout};
 
-pub fn print_prompt() {
+fn print_prompt() {
     print!("$ ");
     stdout().flush().unwrap();
 }
 
 pub fn get_user_input() -> Option<String> {
+    print_prompt();
+
     let mut user_input = String::new();
 
     let bytes_read = stdin()
         .read_line(&mut user_input)
         .expect("error reading user input");
 
-    if bytes_read == 0 {
-        None
-    } else {
-        Some(user_input)
+    match bytes_read {
+        0 => None,
+        _ => Some(user_input),
     }
 }

src/main.rs

@@ -4,6 +4,7 @@ mod error;
 mod exit_code;
 mod interface;
 mod parser;
+mod variables;
 
 fn main() {
     control::run();

src/parser.rs

@@ -1,8 +1,25 @@
 use crate::command::command_builder::CommandBuilder;
 use crate::command::command_sequence::CommandSequence;
+use crate::variables::Variables;
+
+fn parse_variable(characters: &mut Vec<char>, variables: &Variables) -> String {
+    if characters.is_empty() {
+        String::new()
+    } else {
+        let mut current_char = characters.pop().unwrap();
+        let mut var_name = String::new();
+
+        while !characters.is_empty() && !current_char.is_whitespace() {
+            var_name.push(current_char);
+            current_char = characters.pop().unwrap();
+        }
+
+        variables.get(var_name.as_str())
+    }
+}
 
 fn parse_quote(characters: &mut Vec<char>) -> String {
-    let mut quoted = String::default();
+    let mut quoted = String::new();
 
     if !characters.is_empty() {
         let mut current_char = characters.pop().unwrap();
@@ -16,42 +33,49 @@ fn parse_quote(characters: &mut Vec<char>) -> String {
     quoted
 }
 
-fn parse_backslash(characters: &mut Vec<char>) -> Option<char> {
-    let mut escaped_char: Option<char> = None;
-
-    if !characters.is_empty() {
-        escaped_char = Some(characters.pop().unwrap());
-    }
+fn parse_backslash(characters: &mut Vec<char>) -> String {
+    let escaped_char = match characters.is_empty() {
+        false => String::from(characters.pop().unwrap()),
+        true => String::new(),
+    };
 
     escaped_char
 }
 
-fn parse_main(characters: &mut Vec<char>, current_arg: &mut String) -> Vec<String> {
+fn parse_main(
+    characters: &mut Vec<char>,
+    current_arg: &mut String,
+    variables: &Variables,
+) -> Vec<String> {
     if characters.is_empty() {
-        vec![]
+        let mut last_arg = vec![];
+
+        if !current_arg.is_empty() {
+            last_arg.push(current_arg.clone());
+        }
+
+        last_arg
     } else {
         let current_char = characters.pop().unwrap();
 
         if current_char.is_whitespace() {
             if !current_arg.is_empty() {
                 let mut argv: Vec<String> = vec![current_arg.clone()];
-                argv.append(&mut parse_main(characters, &mut String::default()));
+                argv.append(&mut parse_main(characters, &mut String::new(), variables));
 
                 argv
             } else {
-                parse_main(characters, current_arg)
+                parse_main(characters, current_arg, variables)
             }
         } else if current_char == '\\' {
-            let escaped_char = parse_backslash(characters);
-
-            if escaped_char.is_some() {
-                current_arg.push(escaped_char.unwrap());
-            }
-
-            parse_main(characters, current_arg)
+            current_arg.push_str(parse_backslash(characters).as_str());
+            parse_main(characters, current_arg, variables)
+        } else if current_char == '$' {
+            current_arg.push_str(parse_variable(characters, variables).as_str());
+            parse_main(characters, current_arg, variables)
         } else if current_char == '\'' {
             current_arg.push_str(parse_quote(characters).as_str());
-            parse_main(characters, current_arg)
+            parse_main(characters, current_arg, variables)
         } else if current_char == ';' {
             let mut argv: Vec<String> = vec![];
 
@@ -62,17 +86,17 @@ fn parse_main(characters: &mut Vec<char>, current_arg: &mut String) -> Vec<Strin
             argv
         } else {
             current_arg.push(current_char);
-            parse_main(characters, current_arg)
+            parse_main(characters, current_arg, variables)
         }
     }
 }
 
-pub fn parse(line: String) -> CommandSequence {
+pub fn parse(line: String, variables: &Variables) -> CommandSequence {
     let mut characters: Vec<char> = line.chars().rev().collect();
     let mut command_sequence = CommandSequence::new();
 
     while !characters.is_empty() {
-        let argv = parse_main(&mut characters, &mut String::default());
+        let argv = parse_main(&mut characters, &mut String::new(), variables);
 
         if !argv.is_empty() {
             let command = CommandBuilder::new(argv).build();
@@ -82,6 +106,3 @@ pub fn parse(line: String) -> CommandSequence {
 
     command_sequence
 }
-
-#[derive(Debug)]
-struct UnmatchedQuoteError;

src/variables.rs

@@ -0,0 +1,56 @@
+use std::collections::HashMap;
+use std::env::{self, args};
+
+pub struct Variables {
+    variables: HashMap<String, String>,
+}
+
+impl Variables {
+    pub fn new() -> Self {
+        Self {
+            variables: HashMap::new(),
+        }
+    }
+
+    pub fn get(&self, key: &str) -> String {
+        let arg_index = String::from(key).parse::<usize>();
+
+        match arg_index {
+            Ok(index) => match env::args().nth(index) {
+                Some(value) => value,
+                None => String::new(),
+            },
+            Err(_e) => match self.variables.get(key) {
+                Some(value) => value.clone(),
+                None => match env::var(key) {
+                    Ok(value) => value,
+                    Err(_e) => String::new(),
+                },
+            },
+        }
+    }
+
+    pub fn unset(&mut self, key: &str) {
+        let old_value = self.variables.remove(key);
+
+        if old_value.is_none() {
+            env::remove_var(key);
+        }
+    }
+
+    pub fn set(&mut self, key: &str, value: &str) {
+        self.variables
+            .insert(String::from(key), String::from(value));
+    }
+
+    pub fn export(&mut self, key: &str) {
+        let var_to_export = self.variables.get(key);
+
+        if var_to_export.is_some() {
+            env::set_var(key, var_to_export.unwrap());
+            self.variables.remove(key);
+        } else {
+            env::set_var(key, "");
+        }
+    }
+}