macros.rs

  1// Copyright (c) 2017-2018 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
  2//
  3// This Source Code Form is subject to the terms of the Mozilla Public
  4// License, v. 2.0. If a copy of the MPL was not distributed with this
  5// file, You can obtain one at http://mozilla.org/MPL/2.0/.
  6
  7macro_rules! get_attr {
  8    ($elem:ident, $attr:tt, $type:tt) => (
  9        get_attr!($elem, $attr, $type, value, value.parse()?)
 10    );
 11    ($elem:ident, $attr:tt, optional_empty, $value:ident, $func:expr) => (
 12        match $elem.attr($attr) {
 13            Some("") => None,
 14            Some($value) => Some($func),
 15            None => None,
 16        }
 17    );
 18    ($elem:ident, $attr:tt, optional, $value:ident, $func:expr) => (
 19        match $elem.attr($attr) {
 20            Some($value) => Some($func),
 21            None => None,
 22        }
 23    );
 24    ($elem:ident, $attr:tt, required, $value:ident, $func:expr) => (
 25        match $elem.attr($attr) {
 26            Some($value) => $func,
 27            None => return Err(::error::Error::ParseError(concat!("Required attribute '", $attr, "' missing."))),
 28        }
 29    );
 30    ($elem:ident, $attr:tt, default, $value:ident, $func:expr) => (
 31        match $elem.attr($attr) {
 32            Some($value) => $func,
 33            None => ::std::default::Default::default(),
 34        }
 35    );
 36}
 37
 38macro_rules! generate_attribute {
 39    ($(#[$meta:meta])* $elem:ident, $name:tt, {$($(#[$a_meta:meta])* $a:ident => $b:tt),+,}) => (
 40        generate_attribute!($(#[$meta])* $elem, $name, {$($(#[$a_meta])* $a => $b),+});
 41    );
 42    ($(#[$meta:meta])* $elem:ident, $name:tt, {$($(#[$a_meta:meta])* $a:ident => $b:tt),+,}, Default = $default:ident) => (
 43        generate_attribute!($(#[$meta])* $elem, $name, {$($(#[$a_meta])* $a => $b),+}, Default = $default);
 44    );
 45    ($(#[$meta:meta])* $elem:ident, $name:tt, {$($(#[$a_meta:meta])* $a:ident => $b:tt),+}) => (
 46        $(#[$meta])*
 47        #[derive(Debug, Clone, PartialEq)]
 48        pub enum $elem {
 49            $(
 50                $(#[$a_meta])*
 51                $a
 52            ),+
 53        }
 54        impl ::std::str::FromStr for $elem {
 55            type Err = ::error::Error;
 56            fn from_str(s: &str) -> Result<$elem, ::error::Error> {
 57                Ok(match s {
 58                    $($b => $elem::$a),+,
 59                    _ => return Err(::error::Error::ParseError(concat!("Unknown value for '", $name, "' attribute."))),
 60                })
 61            }
 62        }
 63        impl ::minidom::IntoAttributeValue for $elem {
 64            fn into_attribute_value(self) -> Option<String> {
 65                Some(String::from(match self {
 66                    $($elem::$a => $b),+
 67                }))
 68            }
 69        }
 70    );
 71    ($(#[$meta:meta])* $elem:ident, $name:tt, {$($(#[$a_meta:meta])* $a:ident => $b:tt),+}, Default = $default:ident) => (
 72        $(#[$meta])*
 73        #[derive(Debug, Clone, PartialEq)]
 74        pub enum $elem {
 75            $(
 76                $(#[$a_meta])*
 77                $a
 78            ),+
 79        }
 80        impl ::std::str::FromStr for $elem {
 81            type Err = ::error::Error;
 82            fn from_str(s: &str) -> Result<$elem, ::error::Error> {
 83                Ok(match s {
 84                    $($b => $elem::$a),+,
 85                    _ => return Err(::error::Error::ParseError(concat!("Unknown value for '", $name, "' attribute."))),
 86                })
 87            }
 88        }
 89        impl ::minidom::IntoAttributeValue for $elem {
 90            #[allow(unreachable_patterns)]
 91            fn into_attribute_value(self) -> Option<String> {
 92                Some(String::from(match self {
 93                    $elem::$default => return None,
 94                    $($elem::$a => $b),+
 95                }))
 96            }
 97        }
 98        impl ::std::default::Default for $elem {
 99            fn default() -> $elem {
100                $elem::$default
101            }
102        }
103    );
104    ($(#[$meta:meta])* $elem:ident, $name:tt, bool) => (
105        $(#[$meta])*
106        #[derive(Debug, Clone, PartialEq)]
107        pub enum $elem {
108            /// True value, represented by either 'true' or '1'.
109            True,
110            /// False value, represented by either 'false' or '0'.
111            False,
112        }
113        impl ::std::str::FromStr for $elem {
114            type Err = ::error::Error;
115            fn from_str(s: &str) -> Result<Self, ::error::Error> {
116                Ok(match s {
117                    "true" | "1" => $elem::True,
118                    "false" | "0" => $elem::False,
119                    _ => return Err(::error::Error::ParseError(concat!("Unknown value for '", $name, "' attribute."))),
120                })
121            }
122        }
123        impl ::minidom::IntoAttributeValue for $elem {
124            fn into_attribute_value(self) -> Option<String> {
125                match self {
126                    $elem::True => Some(String::from("true")),
127                    $elem::False => None
128                }
129            }
130        }
131        impl ::std::default::Default for $elem {
132            fn default() -> $elem {
133                $elem::False
134            }
135        }
136    );
137}
138
139macro_rules! generate_element_enum {
140    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, {$($(#[$enum_meta:meta])* $enum:ident => $enum_name:tt),+,}) => (
141        generate_element_enum!($(#[$meta])* $elem, $name, $ns, {$($(#[$enum_meta])* $enum => $enum_name),+});
142    );
143    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, {$($(#[$enum_meta:meta])* $enum:ident => $enum_name:tt),+}) => (
144        $(#[$meta])*
145        #[derive(Debug, Clone, PartialEq)]
146        pub enum $elem {
147            $(
148            $(#[$enum_meta])*
149            $enum
150            ),+
151        }
152        impl ::try_from::TryFrom<::minidom::Element> for $elem {
153            type Err = ::error::Error;
154            fn try_from(elem: ::minidom::Element) -> Result<$elem, ::error::Error> {
155                check_ns_only!(elem, $name, $ns);
156                check_no_children!(elem, $name);
157                check_no_attributes!(elem, $name);
158                Ok(match elem.name() {
159                    $($enum_name => $elem::$enum,)+
160                    _ => return Err(::error::Error::ParseError(concat!("This is not a ", $name, " element."))),
161                })
162            }
163        }
164        impl From<$elem> for ::minidom::Element {
165            fn from(elem: $elem) -> ::minidom::Element {
166                ::minidom::Element::builder(match elem {
167                    $($elem::$enum => $enum_name,)+
168                }).ns(::ns::$ns)
169                  .build()
170            }
171        }
172    );
173}
174
175macro_rules! generate_attribute_enum {
176    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, $attr:tt, {$($(#[$enum_meta:meta])* $enum:ident => $enum_name:tt),+,}) => (
177        generate_attribute_enum!($(#[$meta])* $elem, $name, $ns, $attr, {$($(#[$enum_meta])* $enum => $enum_name),+});
178    );
179    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, $attr:tt, {$($(#[$enum_meta:meta])* $enum:ident => $enum_name:tt),+}) => (
180        $(#[$meta])*
181        #[derive(Debug, Clone, PartialEq)]
182        pub enum $elem {
183            $(
184            $(#[$enum_meta])*
185            $enum
186            ),+
187        }
188        impl ::try_from::TryFrom<::minidom::Element> for $elem {
189            type Err = ::error::Error;
190            fn try_from(elem: ::minidom::Element) -> Result<$elem, ::error::Error> {
191                check_ns_only!(elem, $name, $ns);
192                check_no_children!(elem, $name);
193                check_no_unknown_attributes!(elem, $name, [$attr]);
194                Ok(match get_attr!(elem, $attr, required) {
195                    $($enum_name => $elem::$enum,)+
196                    _ => return Err(::error::Error::ParseError(concat!("Invalid ", $name, " ", $attr, " value."))),
197                })
198            }
199        }
200        impl From<$elem> for ::minidom::Element {
201            fn from(elem: $elem) -> ::minidom::Element {
202                ::minidom::Element::builder($name)
203                        .ns(::ns::$ns)
204                        .attr($attr, match elem {
205                             $($elem::$enum => $enum_name,)+
206                         })
207                         .build()
208            }
209        }
210    );
211}
212
213macro_rules! check_self {
214    ($elem:ident, $name:tt, $ns:ident) => (
215        check_self!($elem, $name, $ns, $name);
216    );
217    ($elem:ident, $name:tt, $ns:ident, $pretty_name:tt) => (
218        if !$elem.is($name, ::ns::$ns) {
219            return Err(::error::Error::ParseError(concat!("This is not a ", $pretty_name, " element.")));
220        }
221    );
222}
223
224macro_rules! check_ns_only {
225    ($elem:ident, $name:tt, $ns:ident) => (
226        if !$elem.has_ns(::ns::$ns) {
227            return Err(::error::Error::ParseError(concat!("This is not a ", $name, " element.")));
228        }
229    );
230}
231
232macro_rules! check_no_children {
233    ($elem:ident, $name:tt) => (
234        for _ in $elem.children() {
235            return Err(::error::Error::ParseError(concat!("Unknown child in ", $name, " element.")));
236        }
237    );
238}
239
240macro_rules! check_no_attributes {
241    ($elem:ident, $name:tt) => (
242        for _ in $elem.attrs() {
243            return Err(::error::Error::ParseError(concat!("Unknown attribute in ", $name, " element.")));
244        }
245    );
246}
247
248macro_rules! check_no_unknown_attributes {
249    ($elem:ident, $name:tt, [$($attr:tt),*]) => (
250        for (_attr, _) in $elem.attrs() {
251            $(
252            if _attr == $attr {
253                continue;
254            }
255            )*
256            return Err(::error::Error::ParseError(concat!("Unknown attribute in ", $name, " element.")));
257        }
258    );
259}
260
261macro_rules! generate_empty_element {
262    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident) => (
263        $(#[$meta])*
264        #[derive(Debug, Clone)]
265        pub struct $elem;
266
267        impl ::try_from::TryFrom<::minidom::Element> for $elem {
268            type Err = ::error::Error;
269
270            fn try_from(elem: ::minidom::Element) -> Result<$elem, ::error::Error> {
271                check_self!(elem, $name, $ns);
272                check_no_children!(elem, $name);
273                check_no_attributes!(elem, $name);
274                Ok($elem)
275            }
276        }
277
278        impl From<$elem> for ::minidom::Element {
279            fn from(_: $elem) -> ::minidom::Element {
280                ::minidom::Element::builder($name)
281                        .ns(::ns::$ns)
282                        .build()
283            }
284        }
285    );
286}
287
288macro_rules! generate_id {
289    ($(#[$meta:meta])* $elem:ident) => (
290        $(#[$meta])*
291        #[derive(Debug, Clone, PartialEq, Eq, Hash)]
292        pub struct $elem(pub String);
293        impl ::std::str::FromStr for $elem {
294            type Err = ::error::Error;
295            fn from_str(s: &str) -> Result<$elem, ::error::Error> {
296                // TODO: add a way to parse that differently when needed.
297                Ok($elem(String::from(s)))
298            }
299        }
300        impl ::minidom::IntoAttributeValue for $elem {
301            fn into_attribute_value(self) -> Option<String> {
302                Some(self.0)
303            }
304        }
305    );
306}
307
308macro_rules! generate_elem_id {
309    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident) => (
310        $(#[$meta])*
311        #[derive(Debug, Clone, PartialEq, Eq, Hash)]
312        pub struct $elem(pub String);
313        impl ::std::str::FromStr for $elem {
314            type Err = ::error::Error;
315            fn from_str(s: &str) -> Result<$elem, ::error::Error> {
316                // TODO: add a way to parse that differently when needed.
317                Ok($elem(String::from(s)))
318            }
319        }
320        impl ::try_from::TryFrom<::minidom::Element> for $elem {
321            type Err = ::error::Error;
322            fn try_from(elem: ::minidom::Element) -> Result<$elem, ::error::Error> {
323                check_self!(elem, $name, $ns);
324                check_no_children!(elem, $name);
325                check_no_attributes!(elem, $name);
326                // TODO: add a way to parse that differently when needed.
327                Ok($elem(elem.text()))
328            }
329        }
330        impl From<$elem> for ::minidom::Element {
331            fn from(elem: $elem) -> ::minidom::Element {
332                ::minidom::Element::builder($name)
333                        .ns(::ns::$ns)
334                        .append(elem.0)
335                        .build()
336            }
337        }
338    );
339}
340
341macro_rules! start_decl {
342    (Vec, $type:ty) => (
343        Vec<$type>
344    );
345    (Option, $type:ty) => (
346        Option<$type>
347    );
348    (Required, $type:ty) => (
349        $type
350    );
351}
352
353macro_rules! start_parse_elem {
354    ($temp:ident: Vec) => (
355        let mut $temp = Vec::new();
356    );
357    ($temp:ident: Option) => (
358        let mut $temp = None;
359    );
360    ($temp:ident: Required) => (
361        let mut $temp = None;
362    );
363}
364
365macro_rules! do_parse {
366    ($elem:ident, Element) => (
367        $elem.clone()
368    );
369    ($elem:ident, String) => (
370        $elem.text()
371    );
372    ($elem:ident, $constructor:ident) => (
373        $constructor::try_from($elem.clone())?
374    );
375}
376
377macro_rules! do_parse_elem {
378    ($temp:ident: Vec = $constructor:ident => $elem:ident, $name:tt, $parent_name:tt) => (
379        $temp.push(do_parse!($elem, $constructor));
380    );
381    ($temp:ident: Option = $constructor:ident => $elem:ident, $name:tt, $parent_name:tt) => (
382        if $temp.is_some() {
383            return Err(::error::Error::ParseError(concat!("Element ", $parent_name, " must not have more than one ", $name, " child.")));
384        }
385        $temp = Some(do_parse!($elem, $constructor));
386    );
387    ($temp:ident: Required = $constructor:ident => $elem:ident, $name:tt, $parent_name:tt) => (
388        if $temp.is_some() {
389            return Err(::error::Error::ParseError(concat!("Element ", $parent_name, " must not have more than one ", $name, " child.")));
390        }
391        $temp = Some(do_parse!($elem, $constructor));
392    );
393}
394
395macro_rules! finish_parse_elem {
396    ($temp:ident: Vec = $name:tt, $parent_name:tt) => (
397        $temp
398    );
399    ($temp:ident: Option = $name:tt, $parent_name:tt) => (
400        $temp
401    );
402    ($temp:ident: Required = $name:tt, $parent_name:tt) => (
403        $temp.ok_or(::error::Error::ParseError(concat!("Missing child ", $name, " in ", $parent_name, " element.")))?
404    );
405}
406
407macro_rules! generate_serialiser {
408    ($parent:ident, $elem:ident, Required, String, ($name:tt, $ns:ident)) => (
409        ::minidom::Element::builder($name)
410            .ns(::ns::$ns)
411            .append($parent.$elem)
412            .build()
413    );
414    ($parent:ident, $elem:ident, Option, String, ($name:tt, $ns:ident)) => (
415        $parent.$elem.map(|elem|
416            ::minidom::Element::builder($name)
417                .ns(::ns::$ns)
418                .append(elem)
419                .build())
420    );
421    ($parent:ident, $elem:ident, $_:ident, $constructor:ident, ($name:tt, $ns:ident)) => (
422        $parent.$elem
423    );
424}
425
426macro_rules! generate_element {
427    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, attributes: [$($(#[$attr_meta:meta])* $attr:ident: $attr_type:ty = $attr_name:tt => $attr_action:tt),+,]) => (
428        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [$($(#[$attr_meta])* $attr: $attr_type = $attr_name => $attr_action),*], children: []);
429    );
430    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, attributes: [$($(#[$attr_meta:meta])* $attr:ident: $attr_type:ty = $attr_name:tt => $attr_action:tt),+]) => (
431        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [$($(#[$attr_meta])* $attr: $attr_type = $attr_name => $attr_action),*], children: []);
432    );
433    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, children: [$($(#[$child_meta:meta])* $child_ident:ident: $coucou:tt<$child_type:ty> = ($child_name:tt, $child_ns:ident) => $child_constructor:ident),*]) => (
434        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [], children: [$($(#[$child_meta])* $child_ident: $coucou<$child_type> = ($child_name, $child_ns) => $child_constructor),*]);
435    );
436    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, attributes: [$($(#[$attr_meta:meta])* $attr:ident: $attr_type:ty = $attr_name:tt => $attr_action:tt),*,], children: [$($(#[$child_meta:meta])* $child_ident:ident: $coucou:tt<$child_type:ty> = ($child_name:tt, $child_ns:ident) => $child_constructor:ident),*]) => (
437        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [$($(#[$attr_meta])* $attr: $attr_type = $attr_name => $attr_action),*], children: [$($(#[$child_meta])* $child_ident: $coucou<$child_type> = ($child_name, $child_ns) => $child_constructor),*]);
438    );
439    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, text: ($(#[$text_meta:meta])* $text_ident:ident: $codec:ident < $text_type:ty >)) => (
440        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [], children: [], text: ($(#[$text_meta])* $text_ident: $codec<$text_type>));
441    );
442    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, attributes: [$($(#[$attr_meta:meta])* $attr:ident: $attr_type:ty = $attr_name:tt => $attr_action:tt),+], text: ($(#[$text_meta:meta])* $text_ident:ident: $codec:ident < $text_type:ty >)) => (
443        generate_element!($(#[$meta])* $elem, $name, $ns, attributes: [$($(#[$attr_meta])* $attr: $attr_type = $attr_name => $attr_action),*], children: [], text: ($(#[$text_meta])* $text_ident: $codec<$text_type>));
444    );
445    ($(#[$meta:meta])* $elem:ident, $name:tt, $ns:ident, attributes: [$($(#[$attr_meta:meta])* $attr:ident: $attr_type:ty = $attr_name:tt => $attr_action:tt),*], children: [$($(#[$child_meta:meta])* $child_ident:ident: $coucou:tt<$child_type:ty> = ($child_name:tt, $child_ns:ident) => $child_constructor:ident),*] $(, text: ($(#[$text_meta:meta])* $text_ident:ident: $codec:ident < $text_type:ty >))*) => (
446        $(#[$meta])*
447        #[derive(Debug, Clone)]
448        pub struct $elem {
449            $(
450            $(#[$attr_meta])*
451            pub $attr: $attr_type,
452            )*
453            $(
454            $(#[$child_meta])*
455            pub $child_ident: start_decl!($coucou, $child_type),
456            )*
457            $(
458            $(#[$text_meta])*
459            pub $text_ident: $text_type,
460            )*
461        }
462
463        impl ::try_from::TryFrom<::minidom::Element> for $elem {
464            type Err = ::error::Error;
465
466            fn try_from(elem: ::minidom::Element) -> Result<$elem, ::error::Error> {
467                check_self!(elem, $name, $ns);
468                check_no_unknown_attributes!(elem, $name, [$($attr_name),*]);
469                $(
470                start_parse_elem!($child_ident: $coucou);
471                )*
472                for _child in elem.children() {
473                    $(
474                    if _child.is($child_name, ::ns::$child_ns) {
475                        do_parse_elem!($child_ident: $coucou = $child_constructor => _child, $child_name, $name);
476                        continue;
477                    }
478                    )*
479                    return Err(::error::Error::ParseError(concat!("Unknown child in ", $name, " element.")));
480                }
481                Ok($elem {
482                    $(
483                    $attr: get_attr!(elem, $attr_name, $attr_action),
484                    )*
485                    $(
486                    $child_ident: finish_parse_elem!($child_ident: $coucou = $child_name, $name),
487                    )*
488                    $(
489                    $text_ident: $codec::decode(&elem.text())?,
490                    )*
491                })
492            }
493        }
494
495        impl From<$elem> for ::minidom::Element {
496            fn from(elem: $elem) -> ::minidom::Element {
497                ::minidom::Element::builder($name)
498                        .ns(::ns::$ns)
499                        $(
500                        .attr($attr_name, elem.$attr)
501                        )*
502                        $(
503                        .append(generate_serialiser!(elem, $child_ident, $coucou, $child_constructor, ($child_name, $child_ns)))
504                        )*
505                        $(
506                        .append($codec::encode(&elem.$text_ident))
507                        )*
508                        .build()
509            }
510        }
511    );
512}