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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
use proc_macro::{token_stream, Delimiter, Span, TokenStream, TokenTree};
use quote::quote;
use syn::{Fields, FieldsUnnamed, Ident, Variant};
struct Tag {
id: u64,
global: bool,
path: Vec<u64>,
name: Ident,
r#type: Option<String>, // None -> Master
}
#[proc_macro]
pub fn define_ebml(ts: TokenStream) -> TokenStream {
let mut ts = ts.into_iter();
let mut tags = vec![];
parse_kt(&mut tags, &mut ts, vec![]);
let enum_variants = tags
.iter()
.map(|e| Variant {
ident: e.name.clone(),
attrs: vec![],
fields: Fields::Unnamed(
syn::parse2::<FieldsUnnamed>(match e.r#type.clone() {
None => quote!((Master)),
Some(r#type) => match r#type.as_str() {
"Uint" => quote!((u64)),
"Utf8" => quote!((String)),
"Binary" => quote!((Vec<u8>)),
_ => panic!("unsupported type {}", r#type),
},
})
.expect("parse type"),
),
discriminant: None,
})
.collect::<Vec<_>>();
let path_match = tags
.iter()
.map(|e| {
let name = &e.name;
let mut path = e.path.clone();
path.reverse();
if e.global {
quote! { Self::#name(_) => None }
} else {
quote! { Self::#name(_) => Some(&[#(#path),*]) }
}
})
.collect::<Vec<_>>();
let parse_match = tags
.iter()
.map(|Tag { id, name, .. }| {
quote! { #id => Self::#name(crate::ValueFromBuf::from_buf(data)?) }
})
.collect::<Vec<_>>();
quote! {
use crate::Master;
pub enum MatroskaTag {
#(#enum_variants),*
}
impl MatroskaTag {
/// returns path in **reverse** order or None if global.
pub fn path(&self) -> Option<&'static [u64]> {
match self { #(#path_match),* }
}
pub fn parse(id: u64, data: &[u8]) -> anyhow::Result<Self> {
Ok(match id { #(#parse_match),*, _ => anyhow::bail!("unknown id") })
}
}
}
.into()
}
fn parse_kt(tags: &mut Vec<Tag>, ts: &mut token_stream::IntoIter, path: Vec<u64>) {
let mut next_glob = false;
loop {
let global = next_glob;
next_glob = false;
let name = if let Some(tt) = ts.next() {
if let TokenTree::Ident(name) = tt {
if &name.to_string() == "global" {
next_glob = true;
continue;
}
name.to_string()
} else {
panic!("expected ident")
}
} else {
break;
};
let id = if let Some(TokenTree::Group(gr)) = ts.next() {
assert_eq!(gr.delimiter(), Delimiter::Bracket);
let mut ts = gr.stream().into_iter();
if let TokenTree::Literal(lit) = ts.next().unwrap() {
u64::from_str_radix(&lit.to_string()[2..], 16).unwrap()
} else {
panic!("literal expected")
}
} else {
panic!("group expected")
};
if let Some(TokenTree::Punct(p)) = ts.next() {
assert_eq!(p.as_char(), ':')
} else {
panic!("colon expected")
}
match ts.next() {
Some(TokenTree::Group(gr)) => {
// eprintln!("entering group");
let mut ts = gr.stream().into_iter();
tags.push(Tag {
global,
id,
name: Ident::new(&name, Span::call_site().into()),
path: path.clone(),
r#type: None,
});
let mut path = path.clone();
path.push(id);
parse_kt(tags, &mut ts, path);
// eprintln!("leaving group");
}
Some(TokenTree::Ident(r#type)) => {
let r#type = r#type.to_string();
// eprintln!("global={global} id={id}, type={}", r#type);
tags.push(Tag {
id,
name: Ident::new(&name, Span::call_site().into()),
path: path.clone(),
global,
r#type: Some(r#type),
})
}
_ => panic!("group or ident expected"),
}
if let Some(TokenTree::Punct(p)) = ts.next() {
assert_eq!(p.as_char(), ',')
} else {
panic!("colon expected")
}
}
}
|
