rrecutils/src/tools/tojson.rs

extern crate clap;
extern crate rrecutils;
extern crate serde_json;

use std::{fmt,fs,io};

use serde_json::Value;
use serde_json::map::Map;

fn record_to_json(rec: &rrecutils::Record) -> Value {
    let mut m = Map::new();
    for tup in rec.fields.iter() {
        let k = tup.0.clone();
        let v = tup.1.clone();
        m.insert(k, Value::String(v));
    }
    Value::Object(m)
}

fn unwrap_err<L, R: fmt::Debug>(value: Result<L, R>) -> L {
    match value {
        Ok(v) => v,
        Err(err) => {
            println!("{:?}", err);
            std::process::exit(99)
        }
    }
}

fn main() {
    let matches = clap::App::new("rr-to-json")
        .version("0.0")
        .author("Getty Ritter <rrecutils@infinitenegativeutility.com>")
        .about("Display the Rust AST for a Recutils file")
        .arg(clap::Arg::with_name("pretty")
             .short("p")
             .long("pretty")
             .help("Pretty-print the resulting JSON"))
        .arg(clap::Arg::with_name("input")
             .short("i")
             .long("input")
             .value_name("FILE")
             .help("The input recfile (or - for stdin)"))
        .arg(clap::Arg::with_name("output")
             .short("o")
             .long("output")
             .value_name("FILE")
             .help("The desired output location (or - for stdout)"))
        .get_matches();

    let stdin = io::stdin();

    let input: Box<io::BufRead> =
        match matches.value_of("input").unwrap_or("-") {
            "-" => Box::new(stdin.lock()),
            path =>
                Box::new(io::BufReader::new(unwrap_err(fs::File::open(path)))),
        };

    let json = Value::Array(unwrap_err(rrecutils::Recfile::parse(input))
                            .records
                            .iter()
                            .map(|x| record_to_json(x))
                            .collect());

    let mut output: Box<io::Write> =
        match matches.value_of("output").unwrap_or("-") {
            "-" => Box::new(io::stdout()),
            path => Box::new(unwrap_err(fs::File::open(path))),
        };

    let serialized = if matches.is_present("pretty") {
        unwrap_err(serde_json::to_string_pretty(&json))
    } else {
        json.to_string()
    };

    unwrap_err(writeln!(output, "{}", serialized));

}