Restructuring + added the SetArgs Env
This commit is contained in:
parent
6b9c73cc03
commit
ab11cf6f74
7 changed files with 586 additions and 535 deletions
282
src/env.rs
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282
src/env.rs
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@ -0,0 +1,282 @@
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//! Defines tools for interacting with the environment
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//! of the shell.
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use super::{ Error, Result, exec, };
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use std::{collections::HashMap, io::Write, iter::FromIterator};
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/// An environment used to [evaluate expressions](mod@super::eval) or
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/// [execute programs](mod@super::exec).
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pub trait Env {
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/// Get the arguments passed to the environment.
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fn args (&self) -> Args;
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/// Bind a value to a name.
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fn bind (&mut self, name: &str, value: &str);
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/// Get a bound value from the env.
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fn get (&self, name: &str) -> Option<String>;
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/// Get the current working directory.
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fn working_dir (&self) -> Result<std::path::PathBuf>;
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/// Change the working directory.
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fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()>;
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/// Write to stdout.
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fn stdout (&mut self, data: &str) -> Result<()>;
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/// Search the `PATH` variable for the `query`. The default implementation
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/// is derived from [`Env::get`].
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fn search (&self, query: &str) -> Option<exec::Program> {
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self.get("PATH")?
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.split(':')
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.filter_map(|path| {
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std::fs::read_dir(path).ok()
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})
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.flat_map(|dir| {
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dir.filter_map(|entry| entry.ok())
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})
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.map(|file| file.path())
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.find_map(|path| {
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if path.file_name()? == query {
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Some (path)
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} else {
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None
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}
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})
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.map(exec::Program::new)
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}
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/// Create a scoped environment to isolate variable
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/// bindings.
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fn scope (&mut self) -> Scope<'_, Self>
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where
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Self: Sized
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{
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Scope {
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bindings: HashMap::new(),
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parent: self,
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}
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}
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/// Create a new environment that inherits this environments'
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/// behavior, except the args of this env are overwritten with
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/// `args`.
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fn set_args (self, args: Args) -> SetArgs<Self>
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where
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Self: Sized
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{
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SetArgs {
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parent: self,
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args,
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}
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}
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}
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/// Overwrites the arguments in the wrapped [`Env`].
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pub struct SetArgs<E: Env> {
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parent: E,
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args: Args,
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}
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impl<E: Env> Env for SetArgs<E> {
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fn working_dir (&self) -> Result<std::path::PathBuf> {
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self.parent.working_dir()
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}
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fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
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self.parent.set_working_dir(path)
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}
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fn search (&self, query: &str) -> Option<exec::Program> {
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self.parent.search(query)
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}
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fn stdout (&mut self, data: &str) -> Result<()> {
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self.parent.stdout(data)
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}
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fn args (&self) -> Args {
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self.args.clone()
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}
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fn bind (&mut self, name: &str, value: &str) {
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self.parent.bind(name, value);
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}
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fn get (&self, name: &str) -> Option<String> {
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self.parent.get(name)
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}
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}
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/// A one-way barrier for variable bindings. Things executed in
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/// a `Scope` can read the parent's bindings and shadow them, but
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/// not mutate them.
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pub struct Scope <'parent, E: Env> {
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bindings: HashMap <String, String>,
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parent: &'parent mut E,
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}
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impl<E: Env> Env for Scope<'_, E> {
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fn working_dir (&self) -> Result<std::path::PathBuf> {
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self.parent.working_dir()
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}
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fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
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self.parent.set_working_dir(path)
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}
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fn search (&self, query: &str) -> Option<exec::Program> {
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self.parent.search(query)
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}
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fn stdout (&mut self, data: &str) -> Result<()> {
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self.parent.stdout(data)
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}
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fn args (&self) -> Args {
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self.parent.args()
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}
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fn bind (&mut self, name: &str, value: &str) {
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self.bindings.insert(name.to_string(), value.to_string());
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}
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fn get (&self, name: &str) -> Option<String> {
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self.bindings
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.get(name)
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.cloned()
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.or_else(|| {
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self.parent.get(name)
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})
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}
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}
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/// An iterator of arguments.
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#[derive(Default, Clone)]
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pub struct Args (Vec<String>);
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impl<S: ToString> FromIterator<S> for Args {
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fn from_iter <T: IntoIterator<Item = S>> (iter: T) -> Args {
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Args (
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iter.into_iter()
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.map(|s| s.to_string())
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.collect()
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)
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}
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}
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impl Iterator for Args {
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type Item = String;
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fn next (&mut self) -> Option<Self::Item> {
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if self.0.len() > 0 {
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Some (self.0.remove(0))
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} else {
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None
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}
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}
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}
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/// A completely empty environment.
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pub struct Pure {
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bindings: HashMap <String, String>,
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cwd: std::path::PathBuf,
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buf: String,
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}
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impl Pure {
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pub fn init (cwd: impl AsRef<std::path::Path>) -> Pure {
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Pure {
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cwd: cwd.as_ref().to_owned(),
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bindings: HashMap::new(),
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buf: String::new(),
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}
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}
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}
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impl Env for Pure {
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fn args (&self) -> Args {
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std::iter::empty::<String>().collect()
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}
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fn bind (&mut self, name: &str, value: &str) {
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self.bindings.insert(name.to_string(), value.to_string());
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}
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fn get (&self, name: &str) -> Option<String> {
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self.bindings.get(name).cloned()
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}
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fn stdout (&mut self, data: &str) -> Result<()> {
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self.buf += data;
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Ok (())
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}
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fn working_dir (&self) -> Result<std::path::PathBuf> {
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if self.cwd.exists() {
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Ok (self.cwd.clone())
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} else {
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use std::io::ErrorKind;
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Err (Error::Io (ErrorKind::NotFound.into()))
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}
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}
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fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
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if path.is_dir() && path.exists() {
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Ok (self.cwd = path.to_owned())
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} else {
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use std::io::ErrorKind;
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Err (Error::Io (ErrorKind::InvalidInput.into()))
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}
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}
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}
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/// The default global environment, which inherits from the environment of the
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/// shell process.
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pub struct Inherit {}
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impl Env for Inherit {
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fn args (&self) -> Args {
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std::env::args().skip(1).collect()
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}
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fn bind (&mut self, name: &str, value: &str) {
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std::env::set_var(name, value);
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}
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fn get (&self, name: &str) -> Option<String> {
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std::env::var(name).ok()
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}
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fn working_dir (&self) -> Result<std::path::PathBuf> {
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std::env::current_dir()
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.map_err(Error::Io)
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}
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fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
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std::env::set_current_dir(path)
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.map_err(Error::Io)
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}
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fn stdout (&mut self, data: &str) -> Result<()> {
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std::io::stdout().write(data.as_bytes())?;
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Ok (())
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}
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}
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/// Initialize the default environment by inheriting from the environment of
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/// the shell process.
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pub fn inherit () -> impl Env {
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Inherit {}
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}
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pub mod history;
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pub mod job;
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pub mod io;
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1
src/env/history.rs
vendored
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1
src/env/history.rs
vendored
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//! History control.
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1
src/env/io.rs
vendored
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1
src/env/io.rs
vendored
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//! Interaction with stdio and the file system.
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39
src/env/job.rs
vendored
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39
src/env/job.rs
vendored
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//! Job scheduling.
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use super::Result;
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use std::marker::PhantomData;
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use sealed::Sealed;
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mod sealed {
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pub trait Sealed {}
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}
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/// An empty type used to tag a [`Job`] as running in the background.
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pub enum Stopped {}
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impl Sealed for Stopped {}
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/// An empty type used to tag a [`Job`] as running in the foreground.
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pub enum Running {}
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impl Sealed for Running {}
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/// Represents a running process, either in the foreground
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/// or in the background.
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pub struct Job <State: Sealed> {
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_t: PhantomData<State>,
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}
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impl Job<Running> {
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/// Attempt to send this job to the background.
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pub fn bg (self) -> Result<Job<Stopped>> { todo!() }
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}
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impl Job<Stopped> {
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/// Attempt to pull this job to the foreground.
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pub fn fg (self) -> Result<Job<Running>> { todo!() }
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}
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28
src/eval.rs
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28
src/eval.rs
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//! The Rush scripting language.
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use super::{
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Result,
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env::Env,
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};
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/// The value of an expression.
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pub enum Value {
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String (String)
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}
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/// An identifier.
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pub struct Name (String);
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/// Evaluation of expressions in the Rush scripting language.
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pub trait Eval {
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/// Evaluates the code in the context of the given [`Env`].
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fn eval <E> (self, env: &E) -> Result<Value>
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where
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E: Env;
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}
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/// An iterator of parsed code generated from an iterator of raw
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/// code fragments.
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pub struct Parser;
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231
src/exec.rs
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231
src/exec.rs
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//! Execution of commands, builtins and code.
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use super::{
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Result,
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env::Env,
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};
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/// Execute the code in the given environment.
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pub trait Exec {
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/// Run the executable.
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fn exec <E> (&self, env: &mut E) -> Result<()>
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where
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E: Env;
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}
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impl<F> Exec for F
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where
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F: Fn (&mut dyn Env) -> Result<()>
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{
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fn exec <E> (&self, env: &mut E) -> Result<()>
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where
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E: Env
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{
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self (env)
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}
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}
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/// A shell command.
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pub enum Command {
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Program (Program),
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Builtin (Builtin),
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}
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impl Exec for Command {
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fn exec<E>(&self, env: &mut E) -> Result<()>
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where
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E: Env
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{
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match self {
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Command::Builtin (builtin) => builtin.exec(env),
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Command::Program (program) => program.exec(env),
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}
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}
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}
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/// A path to an executable file representing an external program.
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pub struct Program (std::ffi::OsString);
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impl Program {
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/// Create a new [`Program`] struct.
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pub (super) fn new (str: impl AsRef<std::ffi::OsStr>) -> Program {
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Program (str.as_ref().to_owned())
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}
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/// Get the command name as an [`OsStr`](std::ffi::OsStr)
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pub fn as_os_str (&self) -> &std::ffi::OsStr {
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&self.0
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}
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/// Get the [`Path`](std::path::Path) of the file the name references.
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pub fn as_path (&self) -> &std::path::Path {
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self.as_ref()
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}
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}
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impl AsRef<std::path::Path> for Program {
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fn as_ref (&self) -> &std::path::Path {
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std::path::Path::new(&self.0)
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}
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}
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impl Exec for Program {
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fn exec <E> (&self, env: &mut E) -> Result<()>
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where
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E: Env
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{
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use ptyprocess::PtyProcess;
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use std::io::{ BufRead, Read };
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let mut cmd = std::process::Command::new(self.as_os_str());
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cmd.current_dir(env.working_dir()?);
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cmd.args(env.args());
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let proc = PtyProcess::spawn(cmd)
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.unwrap();
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let mut pty = proc
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.get_pty_handle()
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.unwrap();
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while let Ok (true) = proc.is_alive() {
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let mut buf = String::new();
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pty.read_to_string(&mut buf);
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env.stdout(&buf);
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}
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Ok (())
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}
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}
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/// Represents the case that a string fails to parse to a [`Builtin`]
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/// because the associated builtin does not exist. Valid builtin names
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/// are listed in the [`builtin`] module.
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#[derive(Debug)]
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pub struct NotFound;
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/// A shell builtin. See also the [`builtin`] module.
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///
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/// # Examples
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///
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/// The only way to get a `Builtin` is through [`FromStr`].
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///
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/// ```
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/// # use rush::exec::Builtin;
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/// "type".parse::<Builtin>().unwrap();
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/// ```
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///
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/// Parsing an unknown builtin name yields an error.
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///
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/// ```should_panic
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/// # use rush::exec::Builtin;
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/// "sjdkgfhgfkfg"
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/// .parse::<Builtin>()
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/// .unwrap();
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/// ```
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///
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/// [`FromStr`]: std::str::FromStr
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pub struct Builtin (fn (&mut dyn Env) -> Result<()>);
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impl std::str::FromStr for Builtin {
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type Err = NotFound;
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fn from_str (s: &str) -> Result<Self, Self::Err> {
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let ret = Builtin (match s {
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"disown" => builtin::disown,
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"type" => builtin::r#type,
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"exit" => builtin::exit,
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"pwd" => builtin::pwd,
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"fg" => builtin::fg,
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"bg" => builtin::bg,
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"cd" => builtin::cd,
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_ => return Err (NotFound)
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});
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|
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Ok (ret)
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}
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}
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|
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impl Exec for Builtin {
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fn exec <E> (&self, env: &mut E) -> Result<()>
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where
|
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E: Env
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{
|
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self.0.exec(env)
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}
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}
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pub mod builtin {
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//! Shell builtins.
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use super::{ Env, Result, };
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/// Change the current working directory.
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pub fn cd (env: &mut dyn Env) -> Result<()> {
|
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let arg = env.args().next().unwrap();
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env.set_working_dir(arg.as_ref())
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}
|
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|
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/// Print the current working directory.
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pub fn pwd (env: &mut dyn Env) -> Result<()> {
|
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let cwd = env.working_dir()?;
|
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env.stdout(format!("{}", cwd.display()).as_str());
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Ok (())
|
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}
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|
||||
/// Stop the program. Optionally takes an exit code.
|
||||
pub fn exit (env: &mut dyn Env) -> Result<()> {
|
||||
if let Some (code) = env.args().next().and_then(|s| s.parse::<i32>().ok()) {
|
||||
std::process::exit(code)
|
||||
} else {
|
||||
std::process::exit(0)
|
||||
}
|
||||
}
|
||||
|
||||
/// Display information about the type of a command.
|
||||
pub fn r#type (env: &mut dyn Env) -> Result<()> {
|
||||
use crate::exec::Builtin;
|
||||
|
||||
for arg in env.args() {
|
||||
let output = if let Ok (_) = arg.parse::<Builtin>() {
|
||||
format!("{} is a shell builtin", arg)
|
||||
} else if let Some (path) = env.search(&arg) {
|
||||
format!("{} is {}", arg, path.as_path().display())
|
||||
} else {
|
||||
format!("type: {}: not found", arg)
|
||||
};
|
||||
|
||||
env.stdout((output + "\n").as_str())?;
|
||||
}
|
||||
|
||||
Ok (())
|
||||
}
|
||||
|
||||
/// Send a job to the background. See also [`Job::bg`].
|
||||
///
|
||||
/// [`Job::bg`]: crate::job::Job::bg
|
||||
pub fn bg (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
/// Bring a job to the foreground. See also [`Job::fg`].
|
||||
///
|
||||
/// [`Job::fg`]: crate::job::Job::fg
|
||||
pub fn fg (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
/// Disown all background jobs.
|
||||
pub fn disown (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
|
||||
539
src/lib.rs
539
src/lib.rs
|
|
@ -1,5 +1,9 @@
|
|||
//! The Rush shell.
|
||||
|
||||
pub mod env;
|
||||
pub mod exec;
|
||||
pub mod eval;
|
||||
|
||||
use env::job;
|
||||
|
||||
/// Attempt to execute a program, rush expression or builtin.
|
||||
|
|
@ -7,541 +11,6 @@ pub fn exec (prog: impl exec::Exec) -> Result<job::Job<job::Running>> {
|
|||
todo!()
|
||||
}
|
||||
|
||||
pub mod exec {
|
||||
|
||||
//! Execution of commands, builtins and code.
|
||||
|
||||
use super::{
|
||||
Result,
|
||||
env::Env,
|
||||
};
|
||||
|
||||
/// Execute the code in the given environment.
|
||||
pub trait Exec {
|
||||
|
||||
/// Run the executable.
|
||||
fn exec <E> (&self, env: &mut E) -> Result<()>
|
||||
where
|
||||
E: Env;
|
||||
|
||||
}
|
||||
|
||||
impl<F> Exec for F
|
||||
where
|
||||
F: Fn (&mut dyn Env) -> Result<()>
|
||||
{
|
||||
fn exec <E> (&self, env: &mut E) -> Result<()>
|
||||
where
|
||||
E: Env
|
||||
{
|
||||
self (env)
|
||||
}
|
||||
}
|
||||
|
||||
/// A shell command.
|
||||
pub enum Command {
|
||||
Program (Program),
|
||||
Builtin (Builtin),
|
||||
}
|
||||
|
||||
impl Exec for Command {
|
||||
fn exec<E>(&self, env: &mut E) -> Result<()>
|
||||
where
|
||||
E: Env
|
||||
{
|
||||
match self {
|
||||
Command::Builtin (builtin) => builtin.exec(env),
|
||||
Command::Program (program) => program.exec(env),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// A path to an executable file representing an external program.
|
||||
pub struct Program (std::ffi::OsString);
|
||||
|
||||
impl Program {
|
||||
|
||||
/// Create a new [`Program`] struct.
|
||||
pub (super) fn new (str: impl AsRef<std::ffi::OsStr>) -> Program {
|
||||
Program (str.as_ref().to_owned())
|
||||
}
|
||||
|
||||
/// Get the command name as an [`OsStr`](std::ffi::OsStr)
|
||||
pub fn as_os_str (&self) -> &std::ffi::OsStr {
|
||||
&self.0
|
||||
}
|
||||
|
||||
/// Get the [`Path`](std::path::Path) of the file the name references.
|
||||
pub fn as_path (&self) -> &std::path::Path {
|
||||
self.as_ref()
|
||||
}
|
||||
}
|
||||
|
||||
impl AsRef<std::path::Path> for Program {
|
||||
fn as_ref (&self) -> &std::path::Path {
|
||||
std::path::Path::new(&self.0)
|
||||
}
|
||||
}
|
||||
|
||||
impl Exec for Program {
|
||||
fn exec <E> (&self, env: &mut E) -> Result<()>
|
||||
where
|
||||
E: Env
|
||||
{
|
||||
use ptyprocess::PtyProcess;
|
||||
use std::io::{ BufRead, Read };
|
||||
|
||||
let mut cmd = std::process::Command::new(self.as_os_str());
|
||||
|
||||
cmd.current_dir(env.working_dir()?);
|
||||
cmd.args(env.args());
|
||||
|
||||
let proc = PtyProcess::spawn(cmd)
|
||||
.unwrap();
|
||||
|
||||
let mut pty = proc
|
||||
.get_pty_handle()
|
||||
.unwrap();
|
||||
|
||||
while let Ok (true) = proc.is_alive() {
|
||||
let mut buf = String::new();
|
||||
pty.read_to_string(&mut buf);
|
||||
println!("{}", buf);
|
||||
}
|
||||
|
||||
Ok (())
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/// Represents the case that a string fails to parse to a [`Builtin`]
|
||||
/// because the associated builtin does not exist. Valid builtin names
|
||||
/// are listed in the [`builtin`] module.
|
||||
#[derive(Debug)]
|
||||
pub struct NotFound;
|
||||
|
||||
/// A shell builtin. See also the [`builtin`] module.
|
||||
///
|
||||
/// # Examples
|
||||
///
|
||||
/// The only way to get a `Builtin` is through [`FromStr`].
|
||||
///
|
||||
/// ```
|
||||
/// # use rush::exec::Builtin;
|
||||
/// "type".parse::<Builtin>().unwrap();
|
||||
/// ```
|
||||
///
|
||||
/// Parsing an unknown builtin name yields an error.
|
||||
///
|
||||
/// ```should_panic
|
||||
/// # use rush::exec::Builtin;
|
||||
/// "sjdkgfhgfkfg"
|
||||
/// .parse::<Builtin>()
|
||||
/// .unwrap();
|
||||
/// ```
|
||||
///
|
||||
/// [`FromStr`]: std::str::FromStr
|
||||
pub struct Builtin (fn (&mut dyn Env) -> Result<()>);
|
||||
|
||||
impl std::str::FromStr for Builtin {
|
||||
type Err = NotFound;
|
||||
|
||||
fn from_str (s: &str) -> Result<Self, Self::Err> {
|
||||
let ret = Builtin (match s {
|
||||
"disown" => builtin::disown,
|
||||
"type" => builtin::r#type,
|
||||
"exit" => builtin::exit,
|
||||
"pwd" => builtin::pwd,
|
||||
"fg" => builtin::fg,
|
||||
"bg" => builtin::bg,
|
||||
"cd" => builtin::cd,
|
||||
_ => return Err (NotFound)
|
||||
});
|
||||
|
||||
Ok (ret)
|
||||
}
|
||||
}
|
||||
|
||||
impl Exec for Builtin {
|
||||
fn exec <E> (&self, env: &mut E) -> Result<()>
|
||||
where
|
||||
E: Env
|
||||
{
|
||||
self.0.exec(env)
|
||||
}
|
||||
}
|
||||
|
||||
pub mod builtin {
|
||||
|
||||
//! Shell builtins.
|
||||
|
||||
use super::{ Env, Result, };
|
||||
|
||||
/// Change the current working directory.
|
||||
pub fn cd (env: &mut dyn Env) -> Result<()> {
|
||||
let arg = env.args().next().unwrap();
|
||||
env.set_working_dir(arg.as_ref())
|
||||
}
|
||||
|
||||
/// Print the current working directory.
|
||||
pub fn pwd (env: &mut dyn Env) -> Result<()> {
|
||||
let cwd = env.working_dir()?;
|
||||
println!("{}", cwd.display());
|
||||
Ok (())
|
||||
}
|
||||
|
||||
/// Stop the program. Optionally takes an exit code.
|
||||
pub fn exit (env: &mut dyn Env) -> Result<()> {
|
||||
if let Some (code) = env.args().next().and_then(|s| s.parse::<i32>().ok()) {
|
||||
std::process::exit(code)
|
||||
} else {
|
||||
std::process::exit(0)
|
||||
}
|
||||
}
|
||||
|
||||
/// Display information about the type of a command.
|
||||
pub fn r#type (env: &mut dyn Env) -> Result<()> {
|
||||
use crate::exec::Builtin;
|
||||
|
||||
for arg in env.args() {
|
||||
if let Ok (_) = arg.parse::<Builtin>() {
|
||||
println!("{} is a shell builtin", arg);
|
||||
} else if let Some (path) = env.search(&arg) {
|
||||
println!("{} is {}", arg, path.as_path().display());
|
||||
} else {
|
||||
println!("type: {}: not found", arg);
|
||||
}
|
||||
}
|
||||
|
||||
Ok (())
|
||||
}
|
||||
|
||||
/// Send a job to the background. See also [`Job::bg`].
|
||||
///
|
||||
/// [`Job::bg`]: crate::job::Job::bg
|
||||
pub fn bg (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
/// Bring a job to the foreground. See also [`Job::fg`].
|
||||
///
|
||||
/// [`Job::fg`]: crate::job::Job::fg
|
||||
pub fn fg (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
/// Disown all background jobs.
|
||||
pub fn disown (_: &mut dyn Env) -> Result<()> {
|
||||
todo!()
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
|
||||
pub mod eval {
|
||||
|
||||
//! The Rush scripting language.
|
||||
|
||||
use super::{
|
||||
Result,
|
||||
env::Env,
|
||||
};
|
||||
|
||||
/// The value of an expression.
|
||||
pub enum Value {
|
||||
String (String)
|
||||
}
|
||||
|
||||
/// An identifier.
|
||||
pub struct Name (String);
|
||||
|
||||
/// Evaluation of expressions in the Rush scripting language.
|
||||
pub trait Eval {
|
||||
|
||||
/// Evaluates the code in the context of the given [`Env`].
|
||||
fn eval <E> (self, env: &E) -> Result<Value>
|
||||
where
|
||||
E: Env;
|
||||
|
||||
}
|
||||
|
||||
/// An iterator of parsed code generated from an iterator of raw
|
||||
/// code fragments.
|
||||
pub struct Parser;
|
||||
}
|
||||
|
||||
pub mod env {
|
||||
|
||||
//! Defines tools for interacting with the environment
|
||||
//! of the shell.
|
||||
|
||||
use super::{ Error, Result, exec, };
|
||||
|
||||
use std::{
|
||||
iter::FromIterator,
|
||||
collections::HashMap,
|
||||
};
|
||||
|
||||
/// An environment used to [evaluate expressions](mod@super::eval) or
|
||||
/// [execute programs](mod@super::exec).
|
||||
pub trait Env {
|
||||
|
||||
/// Get the arguments passed to the environment.
|
||||
fn args (&self) -> Args;
|
||||
|
||||
/// Bind a value to a name.
|
||||
fn bind (&mut self, name: &str, value: &str);
|
||||
|
||||
/// Get a bound value from the env.
|
||||
fn get (&self, name: &str) -> Option<String>;
|
||||
|
||||
/// Get the current working directory.
|
||||
fn working_dir (&self) -> Result<std::path::PathBuf>;
|
||||
|
||||
/// Change the working directory.
|
||||
fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()>;
|
||||
|
||||
/// Search the `PATH` variable for the `query`. The default implementation
|
||||
/// is derived from [`Env::get`].
|
||||
fn search (&self, query: &str) -> Option<exec::Program> {
|
||||
self.get("PATH")?
|
||||
.split(':')
|
||||
.filter_map(|path| {
|
||||
std::fs::read_dir(path).ok()
|
||||
})
|
||||
.flat_map(|dir| {
|
||||
dir.filter_map(|entry| entry.ok())
|
||||
})
|
||||
.map(|file| file.path())
|
||||
.find_map(|path| {
|
||||
if path.file_name()? == query {
|
||||
Some (path)
|
||||
} else {
|
||||
None
|
||||
}
|
||||
})
|
||||
.map (exec::Program::new)
|
||||
}
|
||||
|
||||
/// Create a scoped environment to isolate variable
|
||||
/// bindings.
|
||||
fn scope (&mut self) -> Scope<'_, Self>
|
||||
where
|
||||
Self: Sized
|
||||
{
|
||||
Scope {
|
||||
bindings: HashMap::new(),
|
||||
parent: self,
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/// A one-way barrier for variable bindings. Things executed in
|
||||
/// a `Scope` can read the parent's bindings and shadow them, but
|
||||
/// not mutate them.
|
||||
pub struct Scope <'parent, E: Env> {
|
||||
bindings: HashMap <String, String>,
|
||||
parent: &'parent mut E,
|
||||
}
|
||||
|
||||
impl<E: Env> Env for Scope<'_, E> {
|
||||
|
||||
fn working_dir (&self) -> Result<std::path::PathBuf> {
|
||||
self.parent.working_dir()
|
||||
}
|
||||
|
||||
fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
|
||||
self.parent.set_working_dir(path)
|
||||
}
|
||||
|
||||
fn search (&self, query: &str) -> Option<exec::Program> {
|
||||
self.parent.search(query)
|
||||
}
|
||||
|
||||
fn args (&self) -> Args {
|
||||
self.parent.args()
|
||||
}
|
||||
|
||||
fn bind (&mut self, name: &str, value: &str) {
|
||||
self.bindings.insert(name.to_string(), value.to_string());
|
||||
}
|
||||
|
||||
fn get (&self, name: &str) -> Option<String> {
|
||||
self.bindings
|
||||
.get(name)
|
||||
.cloned()
|
||||
.or_else(|| {
|
||||
self.parent.get(name)
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
/// An iterator of arguments.
|
||||
#[derive(Default)]
|
||||
pub struct Args (Vec<String>);
|
||||
|
||||
impl<S: ToString> FromIterator<S> for Args {
|
||||
fn from_iter <T: IntoIterator<Item = S>> (iter: T) -> Args {
|
||||
Args (
|
||||
iter.into_iter()
|
||||
.map(|s| s.to_string())
|
||||
.collect()
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl Iterator for Args {
|
||||
type Item = String;
|
||||
|
||||
fn next (&mut self) -> Option<Self::Item> {
|
||||
if self.0.len() > 0 {
|
||||
Some (self.0.remove(0))
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// A completely empty environment.
|
||||
pub struct Pure {
|
||||
bindings: HashMap <String, String>,
|
||||
cwd: std::path::PathBuf,
|
||||
}
|
||||
|
||||
impl Pure {
|
||||
pub fn init (cwd: impl AsRef<std::path::Path>) -> Pure {
|
||||
Pure {
|
||||
cwd: cwd.as_ref().to_owned(),
|
||||
bindings: HashMap::new(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl Env for Pure {
|
||||
fn args (&self) -> Args {
|
||||
std::iter::empty::<String>().collect()
|
||||
}
|
||||
|
||||
fn bind (&mut self, name: &str, value: &str) {
|
||||
self.bindings.insert(name.to_string(), value.to_string());
|
||||
}
|
||||
|
||||
fn get (&self, name: &str) -> Option<String> {
|
||||
self.bindings.get(name).cloned()
|
||||
}
|
||||
|
||||
fn working_dir (&self) -> Result<std::path::PathBuf> {
|
||||
if self.cwd.exists() {
|
||||
Ok (self.cwd.clone())
|
||||
} else {
|
||||
use std::io::ErrorKind;
|
||||
Err (Error::Io (ErrorKind::NotFound.into()))
|
||||
}
|
||||
}
|
||||
|
||||
fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
|
||||
if path.is_dir() && path.exists() {
|
||||
Ok (self.cwd = path.to_owned())
|
||||
} else {
|
||||
use std::io::ErrorKind;
|
||||
Err (Error::Io (ErrorKind::InvalidInput.into()))
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// The default global environment, which inherits from the environment of the
|
||||
/// shell process.
|
||||
pub struct Inherit {}
|
||||
|
||||
impl Env for Inherit {
|
||||
fn args (&self) -> Args {
|
||||
std::env::args().skip(1).collect()
|
||||
}
|
||||
|
||||
fn bind (&mut self, name: &str, value: &str) {
|
||||
std::env::set_var(name, value);
|
||||
}
|
||||
|
||||
fn get (&self, name: &str) -> Option<String> {
|
||||
std::env::var(name).ok()
|
||||
}
|
||||
|
||||
fn working_dir (&self) -> Result<std::path::PathBuf> {
|
||||
std::env::current_dir()
|
||||
.map_err(Error::Io)
|
||||
}
|
||||
|
||||
fn set_working_dir (&mut self, path: &std::path::Path) -> Result<()> {
|
||||
std::env::set_current_dir(path)
|
||||
.map_err(Error::Io)
|
||||
}
|
||||
}
|
||||
|
||||
/// Initialize the default environment by inheriting from the environment of
|
||||
/// the shell process.
|
||||
pub fn inherit () -> impl Env {
|
||||
Inherit {}
|
||||
}
|
||||
|
||||
pub mod history {
|
||||
|
||||
//! History control.
|
||||
|
||||
}
|
||||
|
||||
pub mod io {
|
||||
|
||||
//! Interaction with stdio and the file system.
|
||||
|
||||
}
|
||||
|
||||
pub mod job {
|
||||
|
||||
//! Job scheduling.
|
||||
|
||||
use super::Result;
|
||||
|
||||
use std::marker::PhantomData;
|
||||
|
||||
use sealed::Sealed;
|
||||
mod sealed {
|
||||
pub trait Sealed {}
|
||||
}
|
||||
|
||||
/// An empty type used to tag a [`Job`] as running in the background.
|
||||
pub enum Stopped {}
|
||||
impl Sealed for Stopped {}
|
||||
|
||||
/// An empty type used to tag a [`Job`] as running in the foreground.
|
||||
pub enum Running {}
|
||||
impl Sealed for Running {}
|
||||
|
||||
/// Represents a running process, either in the foreground
|
||||
/// or in the background.
|
||||
pub struct Job <State: Sealed> {
|
||||
_t: PhantomData<State>,
|
||||
}
|
||||
|
||||
impl Job<Running> {
|
||||
|
||||
/// Attempt to send this job to the background.
|
||||
pub fn bg (self) -> Result<Job<Stopped>> { todo!() }
|
||||
|
||||
}
|
||||
|
||||
impl Job<Stopped> {
|
||||
|
||||
/// Attempt to pull this job to the foreground.
|
||||
pub fn fg (self) -> Result<Job<Running>> { todo!() }
|
||||
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
pub use err::{
|
||||
Error,
|
||||
Result,
|
||||
|
|
|
|||
Loading…
Reference in a new issue