forked from media-io/yaserde
-
Notifications
You must be signed in to change notification settings - Fork 0
/
expand_enum.rs
307 lines (273 loc) · 9.55 KB
/
expand_enum.rs
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
use crate::common::{Field, YaSerdeAttribute, YaSerdeField};
use proc_macro2::{Span, TokenStream};
use quote::quote;
use syn::{DataEnum, Fields, Ident};
pub fn parse(
data_enum: &DataEnum,
name: &Ident,
root: &str,
root_attributes: &YaSerdeAttribute,
) -> TokenStream {
let namespaces_matching = root_attributes.get_namespace_matching(
&None,
quote!(enum_namespace),
quote!(named_element),
true,
);
let match_to_enum: TokenStream = data_enum
.variants
.iter()
.map(|variant| parse_variant(variant, name))
.flatten()
.collect();
let flatten = root_attributes.flatten;
quote! {
impl ::yaserde::YaDeserialize for #name {
#[allow(unused_variables)]
fn deserialize<R: ::std::io::Read>(
reader: &mut ::yaserde::de::Deserializer<R>,
) -> ::std::result::Result<Self, ::std::string::String> {
let (named_element, enum_namespace) =
if let ::yaserde::__xml::reader::XmlEvent::StartElement{ name, .. } = reader.peek()?.to_owned() {
(name.local_name.to_owned(), name.namespace.clone())
} else {
(::std::string::String::from(#root), ::std::option::Option::None)
};
let start_depth = reader.depth();
::yaserde::__derive_debug!("Enum {} @ {}: start to parse {:?}", stringify!(#name), start_depth, named_element);
#namespaces_matching
#[allow(unused_assignments, unused_mut)]
let mut enum_value = ::std::option::Option::None;
loop {
let event = reader.peek()?.to_owned();
::yaserde::__derive_trace!("Enum {} @ {}: matching {:?}", stringify!(#name), start_depth, event);
match event {
::yaserde::__xml::reader::XmlEvent::StartElement { ref name, ref attributes, .. } => {
match name.local_name.as_str() {
#match_to_enum
_named_element => {
let _root = reader.next_event();
}
}
if let ::yaserde::__xml::reader::XmlEvent::Characters(content) = reader.peek()?.to_owned() {
match content.as_str() {
#match_to_enum
_ => {}
}
}
}
::yaserde::__xml::reader::XmlEvent::EndElement { ref name } => {
if name.local_name == named_element {
break;
}
let _root = reader.next_event();
}
::yaserde::__xml::reader::XmlEvent::Characters(ref text_content) => {
let _root = reader.next_event();
}
::yaserde::__xml::reader::XmlEvent::EndDocument => {
if #flatten {
break;
}
return ::std::result::Result::Err(
::std::format!("End of document, missing some content ?"),
);
}
event => {
return ::std::result::Result::Err(::std::format!("unknown event {:?}", event))
}
}
}
::yaserde::__derive_debug!("Enum {} @ {}: success", stringify!(#name), start_depth);
match enum_value {
::std::option::Option::Some(value) => ::std::result::Result::Ok(value),
::std::option::Option::None => {
::std::result::Result::Ok(<#name as ::std::default::Default>::default())
},
}
}
}
}
}
fn parse_variant(variant: &syn::Variant, name: &Ident) -> Option<TokenStream> {
let xml_element_name = YaSerdeAttribute::parse(&variant.attrs).xml_element_name(&variant.ident);
let variant_name = {
let label = &variant.ident;
quote! { #name::#label }
};
match variant.fields {
Fields::Unit => Some(quote! {
#xml_element_name => {
enum_value = ::std::option::Option::Some(#variant_name);
}
}),
Fields::Unnamed(ref fields) => {
let field_visitors = build_unnamed_field_visitors(fields);
let call_visitors = build_unnamed_visitor_calls(fields, &variant_name);
if fields.unnamed.len() > 1 {
unimplemented!("enum variant with multiple fields")
}
Some(
fields
.unnamed
.iter()
.take(1)
.map(|_field| {
quote! {
#xml_element_name => {
#field_visitors
#call_visitors
}
}
})
.collect(),
)
}
_ => None,
}
}
fn build_unnamed_field_visitors(fields: &syn::FieldsUnnamed) -> TokenStream {
fields
.unnamed
.iter()
.map(|field| YaSerdeField::new(field.clone()))
.enumerate()
.filter_map(|(idx, field)| {
let visitor_label = Ident::new(&format!("__Visitor_{}", idx), field.get_span());
let make_visitor = |visitor: &Ident, field_type: &TokenStream, fn_body: &TokenStream| {
quote! {
#[allow(non_snake_case, non_camel_case_types)]
struct #visitor_label;
impl<'de> ::yaserde::Visitor<'de> for #visitor_label {
type Value = #field_type;
fn #visitor(
self,
v: &str,
) -> ::std::result::Result<Self::Value, ::std::string::String> {
#fn_body
}
}
}
};
let simple_type_visitor = |simple_type: Field| {
let visitor = simple_type.get_simple_type_visitor();
let field_type = simple_type.into();
make_visitor(
&visitor,
&field_type,
"e! { ::std::result::Result::Ok(#field_type::from_str(v).unwrap()) },
)
};
match field.get_type() {
Field::FieldStruct { struct_name } => {
let struct_id: String = struct_name
.segments
.iter()
.map(|s| s.ident.to_string())
.collect();
Some(make_visitor(
&Ident::new("visit_str", Span::call_site()),
"e! { #struct_name },
"e! {
let content = "<".to_string() + #struct_id + ">" + v + "</" + #struct_id + ">";
let value: ::std::result::Result<#struct_name, ::std::string::String> =
::yaserde::de::from_str(&content);
value
},
))
}
Field::FieldOption { data_type } | Field::FieldVec { data_type } => match *data_type {
Field::FieldStruct { .. } => None,
simple_type => Some(simple_type_visitor(simple_type)),
},
simple_type => Some(simple_type_visitor(simple_type)),
}
})
.collect()
}
fn build_unnamed_visitor_calls(
fields: &syn::FieldsUnnamed,
variant_name: &TokenStream,
) -> TokenStream {
fields
.unnamed
.iter()
.map(|field| YaSerdeField::new(field.clone()))
.enumerate()
.map(|(idx, field)| {
let visitor_label = Ident::new(&format!("__Visitor_{}", idx), field.get_span());
let call_simple_type_visitor = |simple_type: Field, action| {
let visitor = simple_type.get_simple_type_visitor();
let field_type: TokenStream = simple_type.into();
let label_name = format!("field_{}", idx);
Some(quote! {
let visitor = #visitor_label{};
let result = reader.read_inner_value::<#field_type, _>(|reader| {
if let ::yaserde::__xml::reader::XmlEvent::EndElement { .. } = *reader.peek()? {
return visitor.#visitor("");
}
if let ::std::result::Result::Ok(::yaserde::__xml::reader::XmlEvent::Characters(s))
= reader.next_event()
{
visitor.#visitor(&s)
} else {
::std::result::Result::Err(
::std::format!("unable to parse content for {}", #label_name),
)
}
});
if let ::std::result::Result::Ok(value) = result {
#action
}
})
};
let call_struct_visitor = |struct_name, action| {
Some(quote! {
match <#struct_name as ::yaserde::YaDeserialize>::deserialize(reader) {
Ok(value) => {
#action;
let _root = reader.next_event();
},
Err(msg) => {
return Err(msg);
},
}
})
};
let set_val = quote! {
enum_value = ::std::option::Option::Some(#variant_name(value))
};
let set_opt = quote! {
enum_value = ::std::option::Option::Some(#variant_name(::std::option::Option::Some(value)))
};
let set_vec = quote! {
match enum_value {
Some(ref mut v) => match v {
#variant_name(ref mut v) => v.push(value),
_ => {
return ::std::result::Result::Err(
::std::string::String::from("Got sequence of different types"),
);
}
}
None => {
enum_value = ::std::option::Option::Some(#variant_name(vec![value]));
}
}
};
match field.get_type() {
Field::FieldStruct { struct_name } => call_struct_visitor(struct_name, set_val),
Field::FieldOption { data_type } => match *data_type {
Field::FieldStruct { struct_name } => call_struct_visitor(struct_name, set_opt),
simple_type => call_simple_type_visitor(simple_type, set_opt),
},
Field::FieldVec { data_type } => match *data_type {
Field::FieldStruct { struct_name } => call_struct_visitor(struct_name, set_vec),
simple_type => call_simple_type_visitor(simple_type, set_vec),
},
simple_type => call_simple_type_visitor(simple_type, set_val),
}
})
.flatten()
.collect()
}