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use std::iter::Peekable;
use proc_macro::{token_stream, Span, TokenTree};
use time_core::convert::*;
use crate::helpers::{consume_any_ident, consume_number, consume_punct};
use crate::to_tokens::ToTokenTree;
use crate::Error;
enum Period {
Am,
Pm,
_24,
}
pub(crate) struct Time {
pub(crate) hour: u8,
pub(crate) minute: u8,
pub(crate) second: u8,
pub(crate) nanosecond: u32,
}
pub(crate) fn parse(chars: &mut Peekable<token_stream::IntoIter>) -> Result<Time, Error> {
fn consume_period(chars: &mut Peekable<token_stream::IntoIter>) -> (Option<Span>, Period) {
if let Ok(span) = consume_any_ident(&["am", "AM"], chars) {
(Some(span), Period::Am)
} else if let Ok(span) = consume_any_ident(&["pm", "PM"], chars) {
(Some(span), Period::Pm)
} else {
(None, Period::_24)
}
}
let (hour_span, hour) = consume_number("hour", chars)?;
let ((minute_span, minute), (second_span, second), (period_span, period)) =
match consume_period(chars) {
// Nothing but the 12-hour clock hour and AM/PM
(period_span @ Some(_), period) => (
(Span::mixed_site(), 0),
(Span::mixed_site(), 0.),
(period_span, period),
),
(None, _) => {
consume_punct(':', chars)?;
let (minute_span, minute) = consume_number::<u8>("minute", chars)?;
let (second_span, second): (_, f64) = if consume_punct(':', chars).is_ok() {
consume_number("second", chars)?
} else {
(Span::mixed_site(), 0.)
};
let (period_span, period) = consume_period(chars);
(
(minute_span, minute),
(second_span, second),
(period_span, period),
)
}
};
let hour = match (hour, period) {
(0, Period::Am | Period::Pm) => {
return Err(Error::InvalidComponent {
name: "hour",
value: hour.to_string(),
span_start: Some(hour_span),
span_end: Some(period_span.unwrap_or(hour_span)),
});
}
(12, Period::Am) => 0,
(12, Period::Pm) => 12,
(hour, Period::Am | Period::_24) => hour,
(hour, Period::Pm) => hour + 12,
};
if hour >= Hour::per(Day) {
Err(Error::InvalidComponent {
name: "hour",
value: hour.to_string(),
span_start: Some(hour_span),
span_end: Some(period_span.unwrap_or(hour_span)),
})
} else if minute >= Minute::per(Hour) {
Err(Error::InvalidComponent {
name: "minute",
value: minute.to_string(),
span_start: Some(minute_span),
span_end: Some(minute_span),
})
} else if second >= Second::per(Minute) as _ {
Err(Error::InvalidComponent {
name: "second",
value: second.to_string(),
span_start: Some(second_span),
span_end: Some(second_span),
})
} else {
Ok(Time {
hour,
minute,
second: second.trunc() as _,
nanosecond: (second.fract() * Nanosecond::per(Second) as f64).round() as _,
})
}
}
impl ToTokenTree for Time {
fn into_token_tree(self) -> TokenTree {
quote_group! {{
const TIME: ::time::Time = unsafe {
::time::Time::__from_hms_nanos_unchecked(
#(self.hour),
#(self.minute),
#(self.second),
#(self.nanosecond),
)
};
TIME
}}
}
}