rust-jsonnet

====

rust-jsonnet - 为Rust提供的Google Jsonnet（操作数据模板语言）

Google Jsonnet文档：(http://google.github.io/jsonnet/doc/)

解析文件

#[warn(unused_must_use)]
extern crate libc;
extern crate jsonnet;
use libc::c_char;
use std::str;
use std::error::Error;
use std::fs::File;
use std::io::prelude::*;
use std::path::Path;
use std::ffi::CStr;
use std::ffi::CString;
use jsonnet::ffi::command::{ Jsonnet };
pub type JsonnetResult = Result<String, String>;
pub fn ctos(msg_buf : *const c_char)-> String{
    let msg_str: &CStr = unsafe { CStr::from_ptr(msg_buf) };
    let buf: &[u8] = msg_str.to_bytes();
    let str_buf: &str = str::from_utf8(buf).unwrap();
    let msg_data: String = str_buf.to_owned();
    return msg_data;
}

pub fn version(){
    let msg_buf: *const c_char = Jsonnet::version();
    let msg_data: String = ctos(msg_buf);
    println!("{:?}", msg_data);
}

pub fn evaluate_file(){  
    let filename : *const libc::c_char = CString::new("./t.jsonnet") .unwrap().as_ptr();
    let json = match Jsonnet::evaluate_file(filename) {
    Ok(json) => json,
    Err(e) => panic!("{:?}", e)
    };
    println!("{:?}", json);
}

pub fn evaluate_snippet(){
    let path = Path::new("./t.jsonnet");
    let display = path.display();
    let mut file = match File::open(&path) {
    Err(why) => panic!("couldn't open {}: {}", display,
    Error::description(&why)),
    Ok(file) => file,
    };
    let mut s = String::new();
    file.read_to_string(&mut s).unwrap();
    let json_tpl : *const c_char = s.as_ptr() as *const c_char;
    let json = match Jsonnet::evaluate_snippet(json_tpl) {
    Ok(json) => json,
    Err(e) => panic!("{:?}", e)
    };
    println!("{:?}", json);
}

fn main() {
    version();
    evaluate_file();
    evaluate_snippet();
    Jsonnet::destroy();
}