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
#[macro_use] extern crate nom; pub use value::Value; pub use object::Object; use std::str::{self, FromStr}; use nom::{digit, eof, space, not_line_ending, line_ending, alphanumeric, IResult}; pub mod value; pub mod object; pub type Key = String; type Entry = (Key, Value); named!(comment, preceded!(tag!("#"), not_line_ending)); named!(blank, chain!(many0!(terminated!( many0!(alt!(comment | space)), line_ending)), || { &b""[..] })); named!(boolean<Value>, map!( map_res!( map_res!( alt!(tag!("true") | tag!("false")), str::from_utf8), <bool as FromStr>::from_str), From::from)); named!(number<Value>, map!( map_res!( map_res!( digit, str::from_utf8), <i64 as FromStr>::from_str), From::from)); named!(string<Value>, map!( map_res!( delimited!(tag!("\""), take_until!("\""), tag!("\"")), str::from_utf8), From::from)); named!(entries<Object>, map!(many0!(entry), From::from)); named!(object_begin, chain!(space? ~ tag!("{") ~ alt!(blank | space)?, || { &b""[..] })); named!(object_end, chain!(space? ~ tag!("}"), || { &b""[..] })); named!(object<Value>, map!(delimited!(object_begin, entries, object_end), From::from)); named!(value<Value>, delimited!(opt!(space), alt!(number | boolean | string | object), opt!(space))); named!(key<Key>, map_res!( chain!(key: alphanumeric ~ space?, || { str::from_utf8(key).unwrap() }), FromStr::from_str)); named!(entry<Entry>, alt!( chain!(space? ~ key: key ~ space? ~ value: object ~ blank?, || { (key, value) }) | chain!(space? ~ key: key ~ tag!("=") ~ value: value ~ blank?, || { (key, value) }))); named!(root<Object>, terminated!(delimited!(opt!(blank), entries, many0!(alt!(space | line_ending | comment))), eof)); #[derive(Debug)] pub enum Error { ParserFailed(String), Incomplete } pub fn parse<T: AsRef<[u8]>>(input: T) -> Result<Object, Error> { match root(input.as_ref()) { IResult::Done(_, object) => Ok(object), IResult::Error(err) => Err(Error::ParserFailed(format!("{:?}", err))), IResult::Incomplete(_) => Err(Error::Incomplete) } } #[cfg(test)] mod tests { use super::*; #[test] fn it_works() { let data = parse("str = \"test\"\nnum = 42\nbool = true\nobj = { num = 666 }").unwrap(); assert_eq!(data.get("str"), Some(&Value::Str("test".to_string()))); assert_eq!(data.get("num"), Some(&Value::Num(42))); assert_eq!(data.get("bool"), Some(&Value::Bool(true))); let obj = match data.get("obj").unwrap() { &Value::Object(ref obj) => obj, _ => { assert!(false); unreachable!() } }; assert_eq!(obj.get("num"), Some(&Value::Num(666))); } #[test] fn it_fails() { let data = parse("str = \"test\"\nnum = 42\nbool = true\nobj = { num = 666"); assert!(data.is_err(), "data is: {:?}", data); } }