Got rid of tabs
Getty Ritter
7 years ago
8 | 8 | # ...a set of properties |
9 | 9 | properties { |
10 | 10 | light true |
11 |
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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 |
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|
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 | } |