Got rid of tabs
Getty Ritter
8 years ago
| 8 | 8 | # ...a set of properties |
| 9 | 9 | properties { |
| 10 | 10 | light true |
| 11 |
|
|
| 11 | fruit true | |
| 12 | 12 | } |
| 13 | 13 | # ...a bit of descriptive in-game text |
| 14 | 14 | description [ |
| 15 | 15 | "The starberry is a beautiful, bright yellow fruit that glows " |
| 16 |
|
|
| 16 | "ever-so-slightly in the darkness." | |
| 17 | 17 | ] |
| 18 | 18 | } |
| 1 | use std::collections::HashMap; | |
| 2 | use std::iter::Peekable; | |
| 3 | use std::str::{Chars,FromStr}; | |
| 4 | ||
| 5 | #[derive(Clone,Debug,PartialEq)] | |
| 6 | pub enum Adnot { | |
| 7 | Sum(String, Vec<Adnot>), | |
| 8 | Prod(HashMap<String, Adnot>), | |
| 9 | List(Vec<Adnot>), | |
| 10 | Str(String), | |
| 11 | Sym(String), | |
| 12 | Num(i64), | |
| 13 | Dbl(f64), | |
| 14 | } | |
| 15 | ||
| 16 | #[derive(Debug)] | |
| 17 | pub struct AdnotError { | |
| 18 | message: String, | |
| 19 | } | |
| 20 | ||
| 21 | type Stream<'a> = Peekable<Chars<'a>>; | |
| 22 | ||
| 23 | fn fail<T>(s: &str) -> Result<T, AdnotError> { | |
| 24 | Err(AdnotError { message: s.to_string()}) | |
| 25 | } | |
| 26 | ||
| 27 | fn parse_val(s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 28 | if let Some(c) = s.next() { | |
| 29 | match c { | |
| 30 | '[' => parse_list(s), | |
| 31 | '(' => parse_sum(s), | |
| 32 | '{' => parse_prod(s), | |
| 33 | '"' => parse_string(s), | |
| 34 | _ if c.is_digit(10) || c == '-' => parse_num(c, s), | |
| 35 | _ if c.is_alphabetic() => | |
| 36 | Ok(Adnot::Sym(try!(parse_sym(c, s)))), | |
| 37 | _ => fail(&format!("Invalid character: {:?}", c)), | |
| 38 | } | |
| 39 | } else { | |
| 40 | fail("Unexpected end of input") | |
| 41 | } | |
| 42 | } | |
| 43 | ||
| 44 | fn parse_list(s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 45 | let mut vec = vec![]; | |
| 46 | loop { | |
| 47 | skip_space(s); | |
| 48 | if let Some(&']') = s.peek() { | |
| 49 | s.next(); | |
| 50 | return Ok(Adnot::List(vec)); | |
| 51 | } else { | |
| 52 | vec.push(try!(parse_val(s))); | |
| 53 | } | |
| 54 | } | |
| 55 | } | |
| 56 | ||
| 57 | fn parse_sum(s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 58 | let mut vec = vec![]; | |
| 59 | skip_space(s); | |
| 60 | let first = match s.next() { | |
| 61 | Some(c) if c.is_alphabetic() => c, | |
| 62 | Some(c) => { return fail("Expected a tagname character") } | |
| 63 | None => { return fail("Unexpected end of input") } | |
| 64 | }; | |
| 65 | let name = try!(parse_sym(first, s)); | |
| 66 | loop { | |
| 67 | skip_space(s); | |
| 68 | if let Some(&')') = s.peek() { | |
| 69 | s.next(); | |
| 70 | return Ok(Adnot::Sum(name, vec)); | |
| 71 | } else { | |
| 72 | vec.push(try!(parse_val(s))); | |
| 73 | } | |
| 74 | } | |
| 75 | } | |
| 76 | ||
| 77 | fn parse_prod(s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 78 | let mut map = HashMap::new(); | |
| 79 | loop { | |
| 80 | skip_space(s); | |
| 81 | if let Some(&'}') = s.peek() { | |
| 82 | s.next(); | |
| 83 | return Ok(Adnot::Prod(map)); | |
| 84 | } else { | |
| 85 | skip_space(s); | |
| 86 | let first = match s.next() { | |
| 87 | Some(c) if c.is_alphabetic() => c, | |
| 88 | Some(c) => { return fail("Expected a tagname character") } | |
| 89 | None => { return fail("Unexpected end of input") } | |
| 90 | }; | |
| 91 | let key = try!(parse_sym(first, s)); | |
| 92 | skip_space(s); | |
| 93 | let val = try!(parse_val(s)); | |
| 94 | map.insert(key, val); | |
| 95 | } | |
| 96 | } | |
| 97 | } | |
| 98 | ||
| 99 | fn parse_string(s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 100 | let mut chars = Vec::new(); | |
| 101 | while let Some(c) = s.next() { | |
| 102 | if c == '"' { | |
| 103 | break; | |
| 104 | } else if c == '\\' { | |
| 105 | match s.next() { | |
| 106 | Some('n') => chars.push('\n'), | |
| 107 | Some('r') => chars.push('\r'), | |
| 108 | Some('t') => chars.push('\t'), | |
| 109 | Some('\'') => chars.push('\''), | |
| 110 | Some('\"') => chars.push('\"'), | |
| 111 | Some('\\') => chars.push('\\'), | |
| 112 | _ => return fail("Invalid escape sequence"), | |
| 113 | } | |
| 114 | } else { | |
| 115 | chars.push(c); | |
| 116 | } | |
| 117 | }; | |
| 118 | Ok(Adnot::Str(chars.iter().cloned().collect())) | |
| 119 | } | |
| 120 | ||
| 121 | fn parse_num(c: char, s: &mut Stream) -> Result<Adnot, AdnotError> { | |
| 122 | let mut str = vec![c]; | |
| 123 | str.extend(s.take_while(|c| c.is_digit(10))); | |
| 124 | let string: String = str.iter().cloned().collect(); | |
| 125 | Ok(Adnot::Num(i64::from_str(&string).unwrap())) | |
| 126 | } | |
| 127 | ||
| 128 | fn parse_sym(c: char, s: &mut Stream) -> Result<String, AdnotError> { | |
| 129 | let mut chars = vec![c]; | |
| 130 | while let Some(&c) = s.peek() { | |
| 131 | if c.is_alphanumeric() || c == '_' { | |
| 132 | chars.push(s.next().unwrap()); | |
| 133 | } else { | |
| 134 | break; | |
| 135 | } | |
| 136 | }; | |
| 137 | Ok(chars.iter().cloned().collect()) | |
| 138 | } | |
| 139 | ||
| 140 | fn skip_space(s: &mut Stream) { | |
| 141 | while let Some(&c) = s.peek() { | |
| 142 | match c { | |
| 143 | '#' => { skip_comment(s); } | |
| 144 | _ if c.is_whitespace() => { s.next(); } | |
| 145 | _ => break, | |
| 146 | } | |
| 147 | } | |
| 148 | } | |
| 149 | ||
| 150 | fn skip_comment(s: &mut Stream) { | |
| 151 | s.next(); | |
| 152 | while let Some(&c) = s.peek() { | |
| 153 | if c == '\n' || c == '\r' { | |
| 154 | s.next(); | |
| 155 | return; | |
| 156 | } else { | |
| 157 | s.next(); | |
| 158 | } | |
| 159 | } | |
| 160 | } | |
| 161 | ||
| 162 | impl Adnot { | |
| 163 | pub fn parse(s: &str) -> Result<Adnot, AdnotError> { | |
| 164 | let mut stream = s.chars().peekable(); | |
| 165 | skip_space(&mut stream); | |
| 166 | parse_val(&mut stream) | |
| 167 | } | |
| 168 | } |
| 1 | use core::slice::Iter; | |
| 2 | use std::collections::HashMap; | |
| 3 | use std::iter::Peekable; | |
| 4 | use std::mem; | |
| 5 | ||
| 6 | #[derive(Clone,Debug,PartialEq)] | |
| 7 | pub enum Bencode { | |
| 8 | Int(i64), | |
| 9 | Float(f32), | |
| 10 | Str(Vec<u8>), | |
| 11 | List(Vec<Bencode>), | |
| 12 | Dict(HashMap<Vec<u8>, Bencode>), | |
| 13 | } | |
| 14 | ||
| 15 | type Stream<'a> = Peekable<Iter<'a, u8>>; | |
| 16 | ||
| 17 | fn fail<T>(s: &str) -> Result<T, String> { | |
| 18 | Err(s.to_string()) | |
| 19 | } | |
| 20 | ||
| 21 | fn is_digit(b: u8) -> bool { | |
| 22 | b >= 0x30 && b < 0x3a | |
| 23 | } | |
| 24 | ||
| 25 | fn to_digit_usize(b: u8) -> usize { | |
| 26 | (b - 0x30) as usize | |
| 27 | } | |
| 28 | ||
| 29 | fn to_digit_i64(b: u8) -> i64 { | |
| 30 | (b - 0x30) as i64 | |
| 31 | } | |
| 32 | ||
| 33 | fn parse_helper(is: &mut Stream) -> Result<Bencode, String> { | |
| 34 | match is.next() { | |
| 35 | Some(&0x69) => { | |
| 36 | let mut num = 0; | |
| 37 | for &n in is.take_while(|&&x| is_digit(x)) { | |
| 38 | num = num * 10 + to_digit_i64(n); | |
| 39 | } | |
| 40 | Ok(Bencode::Int(num)) | |
| 41 | }, | |
| 42 | Some(&0x66) => { | |
| 43 | let mut next_byte = || { | |
| 44 | match is.next() { | |
| 45 | Some(n) => Ok(*n), | |
| 46 | None => Err("Unexpected end-of-stream"), | |
| 47 | } | |
| 48 | }; | |
| 49 | let buf = [ try!(next_byte()), | |
| 50 | try!(next_byte()), | |
| 51 | try!(next_byte()), | |
| 52 | try!(next_byte()) ]; | |
| 53 | let _ = next_byte(); | |
| 54 | let f = unsafe { mem::transmute::<[u8;4], f32>(buf) }; | |
| 55 | Ok(Bencode::Float(f)) | |
| 56 | }, | |
| 57 | Some(&0x6c) => { | |
| 58 | let mut list = Vec::new(); | |
| 59 | loop { | |
| 60 | match is.peek() { | |
| 61 | Some(&&0x65) => { | |
| 62 | let _ = is.next(); | |
| 63 | break; | |
| 64 | } | |
| 65 | _ => { | |
| 66 | list.push(try!(parse_helper(is))); | |
| 67 | } | |
| 68 | } | |
| 69 | }; | |
| 70 | Ok(Bencode::List(list)) | |
| 71 | }, | |
| 72 | Some(&0x64) => { | |
| 73 | let mut dict = HashMap::new(); | |
| 74 | loop { | |
| 75 | match is.peek() { | |
| 76 | Some(&&0x65) => { | |
| 77 | let _ = is.next(); | |
| 78 | break; | |
| 79 | } | |
| 80 | Some(&&d) if is_digit(d) => { | |
| 81 | let _ = is.next(); | |
| 82 | let key = try!(parse_string(d, is)); | |
| 83 | let val = try!(parse_helper(is)); | |
| 84 | dict.insert(key, val); | |
| 85 | } | |
| 86 | _ => { | |
| 87 | return fail("error while parsing dictionary key"); | |
| 88 | } | |
| 89 | } | |
| 90 | } | |
| 91 | Ok(Bencode::Dict(dict)) | |
| 92 | }, | |
| 93 | Some(&c) if is_digit(c) => { | |
| 94 | Ok(Bencode::Str(try!(parse_string(c, is)))) | |
| 95 | }, | |
| 96 | _ => fail("error while parsing expression"), | |
| 97 | } | |
| 98 | } | |
| 99 | ||
| 100 | fn parse_string(init: u8, is: &mut Stream) -> Result<Vec<u8>, String> { | |
| 101 | let mut size = to_digit_usize(init); | |
| 102 | for &n in is.take_while(|&&x| is_digit(x)) { | |
| 103 | size = size * 10 + to_digit_usize(n); | |
| 104 | } | |
| 105 | Ok(is.take(size).cloned().collect()) | |
| 106 | } | |
| 107 | ||
| 108 | impl Bencode { | |
| 109 | pub fn parse(bs: &[u8]) -> Result<Bencode, String> { | |
| 110 | parse_helper(&mut bs.iter().peekable()) | |
| 111 | } | |
| 112 | ||
| 113 | pub fn get_field(&self, name: &str) -> Result<&Bencode, String> { | |
| 114 | match self { | |
| 115 | &Bencode::Dict(ref ds) => { | |
| 116 | let key = name.as_bytes().to_vec(); | |
| 117 | match ds.get(&key) { | |
| 118 | Some(r) => Ok(r), | |
| 119 | None => fail(&format!("no such key: {:?}", name)), | |
| 120 | } | |
| 121 | } | |
| 122 | _ => fail("not a dictionary"), | |
| 123 | } | |
| 124 | } | |
| 125 | ||
| 126 | pub fn get_idx(&self, idx: usize) -> Result<&Bencode, String> { | |
| 127 | match self { | |
| 128 | &Bencode::List(ref ds) => { | |
| 129 | match ds.get(idx) { | |
| 130 | Some(r) => Ok(r), | |
| 131 | None => fail(&format!("no such index: {:?}", idx)), | |
| 132 | } | |
| 133 | } | |
| 134 | _ => fail("not a list"), | |
| 135 | } | |
| 136 | } | |
| 137 | ||
| 138 | pub fn as_u16(&self) -> Result<u16, String> { | |
| 139 | match self { | |
| 140 | &Bencode::Int(n) => Ok(n as u16), | |
| 141 | _ => fail("not a number"), | |
| 142 | } | |
| 143 | } | |
| 144 | ||
| 145 | pub fn as_i64(&self) -> Result<i64, String> { | |
| 146 | match self { | |
| 147 | &Bencode::Int(n) => Ok(n), | |
| 148 | _ => fail("not a number"), | |
| 149 | } | |
| 150 | } | |
| 151 | ||
| 152 | pub fn as_usize(&self) -> Result<usize, String> { | |
| 153 | match self { | |
| 154 | &Bencode::Int(n) => Ok(n as usize), | |
| 155 | _ => fail("not a number"), | |
| 156 | } | |
| 157 | } | |
| 158 | ||
| 159 | pub fn as_float(&self) -> Result<f32, String> { | |
| 160 | match self { | |
| 161 | &Bencode::Float(f) => Ok(f), | |
| 162 | _ => fail("not a number"), | |
| 163 | } | |
| 164 | } | |
| 165 | ||
| 166 | pub fn as_bytes(&self) -> Result<Vec<u8>, String> { | |
| 167 | match self { | |
| 168 | &Bencode::Str(ref bs) => Ok(bs.clone()), | |
| 169 | _ => fail("not a string"), | |
| 170 | } | |
| 171 | } | |
| 172 | ||
| 173 | pub fn map<A, F>(&self, func: F) -> Result<Vec<A>, String> | |
| 174 | where F: 'static + Fn(&Bencode) -> Result<A, String> | |
| 175 | { | |
| 176 | match self { | |
| 177 | &Bencode::List(ref lst) => { | |
| 178 | let mut vec = Vec::with_capacity(lst.len()); | |
| 179 | for x in lst { | |
| 180 | vec.insert(0, try!(func(x))); | |
| 181 | } | |
| 182 | Ok(vec) | |
| 183 | }, | |
| 184 | _ => fail("not a list"), | |
| 185 | } | |
| 186 | } | |
| 187 | } |