1use alloc::boxed::Box;
4use alloc::string::String;
5use core::num::NonZero;
6use core::str::{self, FromStr};
7
8use super::{ast, unused, Error, Span, Spanned};
9use crate::internal_macros::bug;
10
11#[inline]
13pub(super) fn parse<'a>(
14 ast_items: impl Iterator<Item = Result<ast::Item<'a>, Error>>,
15) -> impl Iterator<Item = Result<Item<'a>, Error>> {
16 ast_items.map(|ast_item| ast_item.and_then(Item::from_ast))
17}
18
19pub(super) enum Item<'a> {
21 Literal(&'a [u8]),
23 Component(Component),
25 Optional {
27 value: Box<[Self]>,
29 span: Span,
31 },
32 First {
34 value: Box<[Box<[Self]>]>,
36 span: Span,
38 },
39}
40
41impl Item<'_> {
42 pub(super) fn from_ast(ast_item: ast::Item<'_>) -> Result<Item<'_>, Error> {
44 Ok(match ast_item {
45 ast::Item::Component {
46 _opening_bracket: _,
47 _leading_whitespace: _,
48 name,
49 modifiers,
50 _trailing_whitespace: _,
51 _closing_bracket: _,
52 } => Item::Component(component_from_ast(&name, &modifiers)?),
53 ast::Item::Literal(Spanned { value, span: _ }) => Item::Literal(value),
54 ast::Item::EscapedBracket {
55 _first: _,
56 _second: _,
57 } => Item::Literal(b"["),
58 ast::Item::Optional {
59 opening_bracket,
60 _leading_whitespace: _,
61 _optional_kw: _,
62 _whitespace: _,
63 nested_format_description,
64 closing_bracket,
65 } => {
66 let items = nested_format_description
67 .items
68 .into_vec()
69 .into_iter()
70 .map(Item::from_ast)
71 .collect::<Result<_, _>>()?;
72 Item::Optional {
73 value: items,
74 span: opening_bracket.to(closing_bracket),
75 }
76 }
77 ast::Item::First {
78 opening_bracket,
79 _leading_whitespace: _,
80 _first_kw: _,
81 _whitespace: _,
82 nested_format_descriptions,
83 closing_bracket,
84 } => {
85 let items = nested_format_descriptions
86 .into_vec()
87 .into_iter()
88 .map(|nested_format_description| {
89 nested_format_description
90 .items
91 .into_vec()
92 .into_iter()
93 .map(Item::from_ast)
94 .collect()
95 })
96 .collect::<Result<_, _>>()?;
97 Item::First {
98 value: items,
99 span: opening_bracket.to(closing_bracket),
100 }
101 }
102 })
103 }
104}
105
106impl<'a> TryFrom<Item<'a>> for crate::format_description::BorrowedFormatItem<'a> {
107 type Error = Error;
108
109 #[inline]
110 fn try_from(item: Item<'a>) -> Result<Self, Self::Error> {
111 match item {
112 Item::Literal(literal) => Ok(Self::Literal(literal)),
113 Item::Component(component) => Ok(Self::Component(component.into())),
114 Item::Optional { value: _, span } => Err(Error {
115 _inner: unused(span.error(
116 "optional items are not supported in runtime-parsed format descriptions",
117 )),
118 public: crate::error::InvalidFormatDescription::NotSupported {
119 what: "optional item",
120 context: "runtime-parsed format descriptions",
121 index: span.start.byte as usize,
122 },
123 }),
124 Item::First { value: _, span } => Err(Error {
125 _inner: unused(span.error(
126 "'first' items are not supported in runtime-parsed format descriptions",
127 )),
128 public: crate::error::InvalidFormatDescription::NotSupported {
129 what: "'first' item",
130 context: "runtime-parsed format descriptions",
131 index: span.start.byte as usize,
132 },
133 }),
134 }
135 }
136}
137
138impl From<Item<'_>> for crate::format_description::OwnedFormatItem {
139 #[inline]
140 fn from(item: Item<'_>) -> Self {
141 match item {
142 Item::Literal(literal) => Self::Literal(literal.to_vec().into_boxed_slice()),
143 Item::Component(component) => Self::Component(component.into()),
144 Item::Optional { value, span: _ } => Self::Optional(Box::new(value.into())),
145 Item::First { value, span: _ } => {
146 Self::First(value.into_vec().into_iter().map(Into::into).collect())
147 }
148 }
149 }
150}
151
152impl<'a> From<Box<[Item<'a>]>> for crate::format_description::OwnedFormatItem {
153 #[inline]
154 fn from(items: Box<[Item<'a>]>) -> Self {
155 let items = items.into_vec();
156 match <[_; 1]>::try_from(items) {
157 Ok([item]) => item.into(),
158 Err(vec) => Self::Compound(vec.into_iter().map(Into::into).collect()),
159 }
160 }
161}
162
163macro_rules! component_definition {
165 (@if_required required then { $($then:tt)* } $(else { $($else:tt)* })?) => { $($then)* };
166 (@if_required then { $($then:tt)* } $(else { $($else:tt)* })?) => { $($($else)*)? };
167 (@if_from_str from_str then { $($then:tt)* } $(else { $($else:tt)* })?) => { $($then)* };
168 (@if_from_str then { $($then:tt)* } $(else { $($else:tt)* })?) => { $($($else)*)? };
169
170 ($vis:vis enum $name:ident {
171 $($variant:ident = $parse_variant:literal {$(
172 $(#[$required:tt])?
173 $field:ident = $parse_field:literal:
174 Option<$(#[$from_str:tt])? $field_type:ty>
175 => $target_field:ident
176 ),* $(,)?}),* $(,)?
177 }) => {
178 $vis enum $name {
179 $($variant($variant),)*
180 }
181
182 $($vis struct $variant {
183 $($field: Option<$field_type>),*
184 })*
185
186 $(impl $variant {
187 #[inline]
189 fn with_modifiers(
190 modifiers: &[ast::Modifier<'_>],
191 _component_span: Span,
192 ) -> Result<Self, Error>
193 {
194 #[allow(unused_mut)]
196 let mut this = Self {
197 $($field: None),*
198 };
199
200 for modifier in modifiers {
201 $(#[expect(clippy::string_lit_as_bytes)]
202 if modifier.key.eq_ignore_ascii_case($parse_field.as_bytes()) {
203 this.$field = component_definition!(@if_from_str $($from_str)?
204 then {
205 parse_from_modifier_value::<$field_type>(&modifier.value)?
206 } else {
207 <$field_type>::from_modifier_value(&modifier.value)?
208 });
209 continue;
210 })*
211 return Err(Error {
212 _inner: unused(modifier.key.span.error("invalid modifier key")),
213 public: crate::error::InvalidFormatDescription::InvalidModifier {
214 value: String::from_utf8_lossy(*modifier.key).into_owned(),
215 index: modifier.key.span.start.byte as usize,
216 }
217 });
218 }
219
220 $(component_definition! { @if_required $($required)? then {
221 if this.$field.is_none() {
222 return Err(Error {
223 _inner: unused(_component_span.error("missing required modifier")),
224 public:
225 crate::error::InvalidFormatDescription::MissingRequiredModifier {
226 name: $parse_field,
227 index: _component_span.start.byte as usize,
228 }
229 });
230 }
231 }})*
232
233 Ok(this)
234 }
235 })*
236
237 impl From<$name> for crate::format_description::Component {
238 #[inline]
239 fn from(component: $name) -> Self {
240 match component {$(
241 $name::$variant($variant { $($field),* }) => {
242 $crate::format_description::component::Component::$variant(
243 $crate::format_description::modifier::$variant {$(
244 $target_field: component_definition! { @if_required $($required)?
245 then {
246 match $field {
247 Some(value) => value.into(),
248 None => bug!("required modifier was not set"),
249 }
250 } else {
251 $field.unwrap_or_default().into()
252 }
253 }
254 ),*}
255 )
256 }
257 )*}
258 }
259 }
260
261 #[inline]
263 fn component_from_ast(
264 name: &Spanned<&[u8]>,
265 modifiers: &[ast::Modifier<'_>],
266 ) -> Result<Component, Error> {
267 $(#[expect(clippy::string_lit_as_bytes)]
268 if name.eq_ignore_ascii_case($parse_variant.as_bytes()) {
269 return Ok(Component::$variant($variant::with_modifiers(&modifiers, name.span)?));
270 })*
271 Err(Error {
272 _inner: unused(name.span.error("invalid component")),
273 public: crate::error::InvalidFormatDescription::InvalidComponentName {
274 name: String::from_utf8_lossy(name).into_owned(),
275 index: name.span.start.byte as usize,
276 },
277 })
278 }
279 }
280}
281
282component_definition! {
284 pub(super) enum Component {
285 Day = "day" {
286 padding = "padding": Option<Padding> => padding,
287 },
288 End = "end" {},
289 Hour = "hour" {
290 padding = "padding": Option<Padding> => padding,
291 base = "repr": Option<HourBase> => is_12_hour_clock,
292 },
293 Ignore = "ignore" {
294 #[required]
295 count = "count": Option<#[from_str] NonZero<u16>> => count,
296 },
297 Minute = "minute" {
298 padding = "padding": Option<Padding> => padding,
299 },
300 Month = "month" {
301 padding = "padding": Option<Padding> => padding,
302 repr = "repr": Option<MonthRepr> => repr,
303 case_sensitive = "case_sensitive": Option<MonthCaseSensitive> => case_sensitive,
304 },
305 OffsetHour = "offset_hour" {
306 sign_behavior = "sign": Option<SignBehavior> => sign_is_mandatory,
307 padding = "padding": Option<Padding> => padding,
308 },
309 OffsetMinute = "offset_minute" {
310 padding = "padding": Option<Padding> => padding,
311 },
312 OffsetSecond = "offset_second" {
313 padding = "padding": Option<Padding> => padding,
314 },
315 Ordinal = "ordinal" {
316 padding = "padding": Option<Padding> => padding,
317 },
318 Period = "period" {
319 case = "case": Option<PeriodCase> => is_uppercase,
320 case_sensitive = "case_sensitive": Option<PeriodCaseSensitive> => case_sensitive,
321 },
322 Second = "second" {
323 padding = "padding": Option<Padding> => padding,
324 },
325 Subsecond = "subsecond" {
326 digits = "digits": Option<SubsecondDigits> => digits,
327 },
328 UnixTimestamp = "unix_timestamp" {
329 precision = "precision": Option<UnixTimestampPrecision> => precision,
330 sign_behavior = "sign": Option<SignBehavior> => sign_is_mandatory,
331 },
332 Weekday = "weekday" {
333 repr = "repr": Option<WeekdayRepr> => repr,
334 one_indexed = "one_indexed": Option<WeekdayOneIndexed> => one_indexed,
335 case_sensitive = "case_sensitive": Option<WeekdayCaseSensitive> => case_sensitive,
336 },
337 WeekNumber = "week_number" {
338 padding = "padding": Option<Padding> => padding,
339 repr = "repr": Option<WeekNumberRepr> => repr,
340 },
341 Year = "year" {
342 padding = "padding": Option<Padding> => padding,
343 repr = "repr": Option<YearRepr> => repr,
344 range = "range": Option<YearRange> => range,
345 base = "base": Option<YearBase> => iso_week_based,
346 sign_behavior = "sign": Option<SignBehavior> => sign_is_mandatory,
347 },
348 }
349}
350
351macro_rules! target_ty {
353 ($name:ident $type:ty) => {
354 $type
355 };
356 ($name:ident) => {
357 $crate::format_description::modifier::$name
358 };
359}
360
361macro_rules! target_value {
363 ($name:ident $variant:ident $value:expr) => {
364 $value
365 };
366 ($name:ident $variant:ident) => {
367 $crate::format_description::modifier::$name::$variant
368 };
369}
370
371macro_rules! modifier {
389 ($(
390 enum $name:ident $(($target_ty:ty))? {
391 $(
392 $(#[$attr:meta])?
393 $variant:ident $(($target_value:expr))? = $parse_variant:literal
394 ),* $(,)?
395 }
396 )+) => {$(
397 #[derive(Default)]
398 enum $name {
399 $($(#[$attr])? $variant),*
400 }
401
402 impl $name {
403 #[inline]
405 fn from_modifier_value(value: &Spanned<&[u8]>) -> Result<Option<Self>, Error> {
406 $(if value.eq_ignore_ascii_case($parse_variant) {
407 return Ok(Some(Self::$variant));
408 })*
409 Err(Error {
410 _inner: unused(value.span.error("invalid modifier value")),
411 public: crate::error::InvalidFormatDescription::InvalidModifier {
412 value: String::from_utf8_lossy(value).into_owned(),
413 index: value.span.start.byte as usize,
414 },
415 })
416 }
417 }
418
419 impl From<$name> for target_ty!($name $($target_ty)?) {
420 #[inline]
421 fn from(modifier: $name) -> Self {
422 match modifier {
423 $($name::$variant => target_value!($name $variant $($target_value)?)),*
424 }
425 }
426 }
427 )+};
428}
429
430modifier! {
432 enum HourBase(bool) {
433 Twelve(true) = b"12",
434 #[default]
435 TwentyFour(false) = b"24",
436 }
437
438 enum MonthCaseSensitive(bool) {
439 False(false) = b"false",
440 #[default]
441 True(true) = b"true",
442 }
443
444 enum MonthRepr {
445 #[default]
446 Numerical = b"numerical",
447 Long = b"long",
448 Short = b"short",
449 }
450
451 enum Padding {
452 Space = b"space",
453 #[default]
454 Zero = b"zero",
455 None = b"none",
456 }
457
458 enum PeriodCase(bool) {
459 Lower(false) = b"lower",
460 #[default]
461 Upper(true) = b"upper",
462 }
463
464 enum PeriodCaseSensitive(bool) {
465 False(false) = b"false",
466 #[default]
467 True(true) = b"true",
468 }
469
470 enum SignBehavior(bool) {
471 #[default]
472 Automatic(false) = b"automatic",
473 Mandatory(true) = b"mandatory",
474 }
475
476 enum SubsecondDigits {
477 One = b"1",
478 Two = b"2",
479 Three = b"3",
480 Four = b"4",
481 Five = b"5",
482 Six = b"6",
483 Seven = b"7",
484 Eight = b"8",
485 Nine = b"9",
486 #[default]
487 OneOrMore = b"1+",
488 }
489
490 enum UnixTimestampPrecision {
491 #[default]
492 Second = b"second",
493 Millisecond = b"millisecond",
494 Microsecond = b"microsecond",
495 Nanosecond = b"nanosecond",
496 }
497
498 enum WeekNumberRepr {
499 #[default]
500 Iso = b"iso",
501 Sunday = b"sunday",
502 Monday = b"monday",
503 }
504
505 enum WeekdayCaseSensitive(bool) {
506 False(false) = b"false",
507 #[default]
508 True(true) = b"true",
509 }
510
511 enum WeekdayOneIndexed(bool) {
512 False(false) = b"false",
513 #[default]
514 True(true) = b"true",
515 }
516
517 enum WeekdayRepr {
518 Short = b"short",
519 #[default]
520 Long = b"long",
521 Sunday = b"sunday",
522 Monday = b"monday",
523 }
524
525 enum YearBase(bool) {
526 #[default]
527 Calendar(false) = b"calendar",
528 IsoWeek(true) = b"iso_week",
529 }
530
531 enum YearRepr {
532 #[default]
533 Full = b"full",
534 Century = b"century",
535 LastTwo = b"last_two",
536 }
537
538 enum YearRange {
539 Standard = b"standard",
540 #[default]
541 Extended = b"extended",
542 }
543}
544
545#[inline]
547fn parse_from_modifier_value<T: FromStr>(value: &Spanned<&[u8]>) -> Result<Option<T>, Error> {
548 str::from_utf8(value)
549 .ok()
550 .and_then(|val| val.parse::<T>().ok())
551 .map(|val| Some(val))
552 .ok_or_else(|| Error {
553 _inner: unused(value.span.error("invalid modifier value")),
554 public: crate::error::InvalidFormatDescription::InvalidModifier {
555 value: String::from_utf8_lossy(value).into_owned(),
556 index: value.span.start.byte as usize,
557 },
558 })
559}