我尝试在生锈中做this tutorial,到目前为止,我有很多问题将C库连接到Rust。
C等效代码:
#include <stdio.h>
#include <stdlib.h>
#include <editline/readline.h>
#include <editline/history.h>
int main(int argc, char** argv) {
/* Print Version and Exit Information */
puts("Lispy Version 0.0.0.0.1");
puts("Press Ctrl+c to Exit\n");
/* In a never ending loop */
while (1) {
/* Output our prompt and get input */
char* input = readline("lispy> ");
/* Add input to history */
add_history(input);
/* Echo input back to user */
printf("No you're a %s\n", input);
/* Free retrived input */
free(input);
}
return 0;
}
到目前为止我得到了这个:
extern crate libc;
use std::c_str;
#[link(name = "readline")]
extern {
fn readline (p: *const libc::c_char) -> *const libc::c_char;
}
fn rust_readline (prompt: &str) -> Option<Box<str>> {
let cprmt = prompt.to_c_str();
cprmt.with_ref(|c_buf| {
unsafe {
let ret = c_str::CString::new (readline (c_buf), true);
ret.as_str().map(|ret| ret.to_owned())
}
})
}
fn main() {
println!("Lispy Version 0.0.1");
println!("Press Ctrl+c to Exit.\n");
// I want to have "history" in Linux of this:
//
// loop {
// print!("lispy> ");
// let input = io::stdin().read_line().unwrap();
// print!("No you're a {}", input);
// }
loop {
let val = rust_readline ("lispy> ");
match val {
None => { break }
_ => {
let input = val.unwrap();
println!("No you're a {}", input);
}
}
}
}
特别是,我遇到了rust_readline函数的问题,我不太清楚里面在做什么。
编辑Cargo.toml,把这个:
[dependencies.readline]
git = "https://github.com/shaleh/rust-readline"
代码更正:
extern crate readline;
fn main() {
println!("Lispy Version 0.0.1");
println!("Press Ctrl+c to Exit.\n");
loop {
let input = readline::readline("lispy> ").unwrap();
readline::add_history(input.as_str());
println!("No you're a {}", input);
}
}
Happy Lisping :-)。
有趣的是,我发现这个问题正在阅读同一本书,但不包括我的搜索查询中的任何书籍特定信息。
现在有一个箱子。 Facon的解决方案对我有用,但是提示字符串总是使用该库打印为垃圾,所以我找了另一个箱子,发现一个工作得很好。这是一个更新的例子:
cargo.toml
:
[dependencies]
# https://crates.io/crates/rustyline
rustyline = "3.0.0"
main.rs
:
extern crate rustyline;
use rustyline::error::ReadlineError;
use rustyline::Editor;
const HISTORY_FILENAME: &str = "history.txt";
fn main() {
println!("Lispy Version 0.0.1");
println!("Press Ctrl+c to Exit.\n");
// We create an editor for the readline history.
let mut readline_editor = Editor::<()>::new();
// And then load the history, if it exists.
if readline_editor.load_history(HISTORY_FILENAME).is_err() {
println!("No previous history.");
}
loop {
// We read some input from CLI.
let readline = readline_editor.readline("LISPY>> ");
// The reading of the input could fail, if a user uses special
// key combinations. So we match against the readline Result
// type. Result can either be some `Ok` or an some `Err`.
match readline {
Ok(line) => {
readline_editor.add_history_entry(line.as_ref());
println!("No, you are {}", line);
},
Err(ReadlineError::Interrupted) => {
println!("CTRL-C");
break
},
Err(ReadlineError::Eof) => {
println!("CTRL-D");
break
},
Err(err) => {
println!("Error: {:?}", err);
break
}
}
readline_editor.save_history(HISTORY_FILENAME).expect("Could not save to readline history.");
}
}