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use rustpython_vm::obj::objstr::PyStringRef;
use rustpython_vm::pyobject::{PyIterable, PyResult, TryFromObject};
use rustpython_vm::scope::{NameProtocol, Scope};
use rustpython_vm::VirtualMachine;
use rustyline::{
completion::Completer, highlight::Highlighter, hint::Hinter, validate::Validator, Context,
Helper,
};
pub struct ShellHelper<'vm> {
vm: &'vm VirtualMachine,
scope: Scope,
}
fn reverse_string(s: &mut String) {
let rev = s.chars().rev().collect();
*s = rev;
}
fn split_idents_on_dot(line: &str) -> Option<(usize, Vec<String>)> {
let mut words = vec![String::new()];
let mut startpos = 0;
for (i, c) in line.chars().rev().enumerate() {
match c {
'.' => {
if i != 0 && words.last().map_or(false, |s| s.is_empty()) {
return None;
}
reverse_string(words.last_mut().unwrap());
if words.len() == 1 {
startpos = line.len() - i;
}
words.push(String::new());
}
c if c.is_alphanumeric() || c == '_' => words.last_mut().unwrap().push(c),
_ => {
if words.len() == 1 {
if words.last().unwrap().is_empty() {
return None;
}
startpos = line.len() - i;
}
break;
}
}
}
if words == [String::new()] {
return None;
}
reverse_string(words.last_mut().unwrap());
words.reverse();
Some((startpos, words))
}
impl<'vm> ShellHelper<'vm> {
pub fn new(vm: &'vm VirtualMachine, scope: Scope) -> Self {
ShellHelper { vm, scope }
}
#[allow(clippy::type_complexity)]
fn get_available_completions<'w>(
&self,
words: &'w [String],
) -> Option<(
&'w str,
Box<dyn Iterator<Item = PyResult<PyStringRef>> + 'vm>,
)> {
let (first, rest) = words.split_first().unwrap();
let str_iter_method = |obj, name| {
let iter = self.vm.call_method(obj, name, vec![])?;
PyIterable::<PyStringRef>::try_from_object(self.vm, iter)?.iter(self.vm)
};
if let Some((last, parents)) = rest.split_last() {
let mut current = self.scope.load_global(self.vm, first)?;
for attr in parents {
current = self.vm.get_attribute(current.clone(), attr.as_str()).ok()?;
}
let current_iter = str_iter_method(¤t, "__dir__").ok()?;
Some((&last, Box::new(current_iter) as _))
} else {
let globals = str_iter_method(self.scope.globals.as_object(), "keys").ok()?;
let builtins = str_iter_method(&self.vm.builtins, "__dir__").ok()?;
Some((&first, Box::new(Iterator::chain(globals, builtins)) as _))
}
}
fn complete_opt(&self, line: &str) -> Option<(usize, Vec<String>)> {
let (startpos, words) = split_idents_on_dot(line)?;
let (word_start, iter) = self.get_available_completions(&words)?;
let all_completions = iter
.filter(|res| {
res.as_ref()
.ok()
.map_or(true, |s| s.as_str().starts_with(word_start))
})
.collect::<Result<Vec<_>, _>>()
.ok()?;
let mut completions = if word_start.starts_with('_') {
all_completions
} else {
let no_underscore = all_completions
.iter()
.cloned()
.filter(|s| !s.as_str().starts_with('_'))
.collect::<Vec<_>>();
if no_underscore.is_empty() {
all_completions
} else {
no_underscore
}
};
completions.sort_by(|a, b| std::cmp::Ord::cmp(a.as_str(), b.as_str()));
Some((
startpos,
completions
.into_iter()
.map(|s| s.as_str().to_owned())
.collect(),
))
}
}
impl Completer for ShellHelper<'_> {
type Candidate = String;
fn complete(
&self,
line: &str,
pos: usize,
_ctx: &Context,
) -> rustyline::Result<(usize, Vec<String>)> {
Ok(self
.complete_opt(&line[0..pos])
.unwrap_or_else(|| (line.len(), vec!["\t".to_owned()])))
}
}
impl Hinter for ShellHelper<'_> {}
impl Highlighter for ShellHelper<'_> {}
impl Validator for ShellHelper<'_> {}
impl Helper for ShellHelper<'_> {}