rust/src/libstd/rl.rs

// FIXME #3921. This is unsafe because linenoise uses global mutable
// state without mutexes.

use libc::{c_char, c_int};

extern mod rustrt {
    #[legacy_exports];
    fn linenoise(prompt: *c_char) -> *c_char;
    fn linenoiseHistoryAdd(line: *c_char) -> c_int;
    fn linenoiseHistorySetMaxLen(len: c_int) -> c_int;
    fn linenoiseHistorySave(file: *c_char) -> c_int;
    fn linenoiseHistoryLoad(file: *c_char) -> c_int;
    fn linenoiseSetCompletionCallback(callback: *u8);
    fn linenoiseAddCompletion(completions: *(), line: *c_char);
}

/// Add a line to history
pub unsafe fn add_history(line: ~str) -> bool {
    do str::as_c_str(line) |buf| {
        rustrt::linenoiseHistoryAdd(buf) == 1 as c_int
    }
}

/// Set the maximum amount of lines stored
pub unsafe fn set_history_max_len(len: int) -> bool {
    rustrt::linenoiseHistorySetMaxLen(len as c_int) == 1 as c_int
}

/// Save line history to a file
pub unsafe fn save_history(file: ~str) -> bool {
    do str::as_c_str(file) |buf| {
        rustrt::linenoiseHistorySave(buf) == 1 as c_int
    }
}

/// Load line history from a file
pub unsafe fn load_history(file: ~str) -> bool {
    do str::as_c_str(file) |buf| {
        rustrt::linenoiseHistoryLoad(buf) == 1 as c_int
    }
}

/// Print out a prompt and then wait for input and return it
pub unsafe fn read(prompt: ~str) -> Option<~str> {
    do str::as_c_str(prompt) |buf| unsafe {
        let line = rustrt::linenoise(buf);

        if line.is_null() { None }
        else { Some(str::raw::from_c_str(line)) }
    }
}

pub type CompletionCb = fn~(~str, fn(~str));

fn complete_key(_v: @CompletionCb) {}

/// Bind to the main completion callback
pub unsafe fn complete(cb: CompletionCb) unsafe {
    task::local_data::local_data_set(complete_key, @(move cb));

    extern fn callback(line: *c_char, completions: *()) unsafe {
        let cb = copy *task::local_data::local_data_get(complete_key).get();

        do cb(str::raw::from_c_str(line)) |suggestion| {
            do str::as_c_str(suggestion) |buf| {
                rustrt::linenoiseAddCompletion(completions, buf);
            }
        }
    }

    rustrt::linenoiseSetCompletionCallback(callback);
}