1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

mod readline;
#[cfg(not(target_os = "wasi"))]
mod rustyline_helper;

use rustpython_compiler::{compile, error::CompileError, error::CompileErrorType};
use rustpython_parser::error::ParseErrorType;
use rustpython_vm::{
    exceptions::{print_exception, PyBaseExceptionRef},
    obj::objtype,
    pyobject::{ItemProtocol, PyResult},
    scope::Scope,
    VirtualMachine,
};

use readline::{Readline, ReadlineResult};

enum ShellExecResult {
    Ok,
    PyErr(PyBaseExceptionRef),
    Continue,
}

fn shell_exec(vm: &VirtualMachine, source: &str, scope: Scope) -> ShellExecResult {
    match vm.compile(source, compile::Mode::Single, "<stdin>".to_owned()) {
        Ok(code) => {
            match vm.run_code_obj(code, scope.clone()) {
                Ok(value) => {
                    // Save non-None values as "_"
                    if !vm.is_none(&value) {
                        let key = "_";
                        scope.globals.set_item(key, value, vm).unwrap();
                    }
                    ShellExecResult::Ok
                }
                Err(err) => ShellExecResult::PyErr(err),
            }
        }
        Err(CompileError {
            error: CompileErrorType::Parse(ParseErrorType::EOF),
            ..
        }) => ShellExecResult::Continue,
        Err(err) => ShellExecResult::PyErr(vm.new_syntax_error(&err)),
    }
}

pub fn run_shell(vm: &VirtualMachine, scope: Scope) -> PyResult<()> {
    println!(
        "Welcome to the magnificent Rust Python {} interpreter \u{1f631} \u{1f596}",
        crate_version!()
    );

    let mut repl = Readline::new(vm, scope.clone());
    let mut full_input = String::new();

    // Retrieve a `history_path_str` dependent on the OS
    let repl_history_path = match dirs::config_dir() {
        Some(mut path) => {
            path.push("rustpython");
            path.push("repl_history.txt");
            path
        }
        None => ".repl_history.txt".into(),
    };

    if repl.load_history(&repl_history_path).is_err() {
        println!("No previous history.");
    }

    let mut continuing = false;

    loop {
        let prompt_name = if continuing { "ps2" } else { "ps1" };
        let prompt = vm
            .get_attribute(vm.sys_module.clone(), prompt_name)
            .and_then(|prompt| vm.to_str(&prompt));
        let prompt = match prompt {
            Ok(ref s) => s.as_str(),
            Err(_) => "",
        };
        let result = match repl.readline(prompt) {
            ReadlineResult::Line(line) => {
                debug!("You entered {:?}", line);

                repl.add_history_entry(line.trim_end()).unwrap();

                let stop_continuing = line.is_empty();

                if full_input.is_empty() {
                    full_input = line;
                } else {
                    full_input.push_str(&line);
                }
                full_input.push_str("\n");

                if continuing {
                    if stop_continuing {
                        continuing = false;
                    } else {
                        continue;
                    }
                }

                match shell_exec(vm, &full_input, scope.clone()) {
                    ShellExecResult::Ok => {
                        full_input.clear();
                        Ok(())
                    }
                    ShellExecResult::Continue => {
                        continuing = true;
                        Ok(())
                    }
                    ShellExecResult::PyErr(err) => {
                        full_input.clear();
                        Err(err)
                    }
                }
            }
            ReadlineResult::Interrupt => {
                continuing = false;
                full_input.clear();
                let keyboard_interrupt =
                    vm.new_exception_empty(vm.ctx.exceptions.keyboard_interrupt.clone());
                Err(keyboard_interrupt)
            }
            ReadlineResult::EOF => {
                break;
            }
            ReadlineResult::EncodingError => {
                eprintln!("Invalid UTF-8 entered");
                Ok(())
            }
            ReadlineResult::Other(err) => {
                eprintln!("Readline error: {:?}", err);
                break;
            }
            ReadlineResult::IO(err) => {
                eprintln!("IO error: {:?}", err);
                break;
            }
        };

        if let Err(exc) = result {
            if objtype::isinstance(&exc, &vm.ctx.exceptions.system_exit) {
                repl.save_history(&repl_history_path).unwrap();
                return Err(exc);
            }
            print_exception(vm, &exc);
        }
    }
    repl.save_history(&repl_history_path).unwrap();

    Ok(())
}