From 2aa4a82499d4becd2284cdb482213d541b8804dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 16:29:10 +0200 Subject: Adding upstream version 86.0.1. Signed-off-by: Daniel Baumann --- third_party/rust/chrono/src/format/scan.rs | 318 +++++++++++++++++++++++++++++ 1 file changed, 318 insertions(+) create mode 100644 third_party/rust/chrono/src/format/scan.rs (limited to 'third_party/rust/chrono/src/format/scan.rs') diff --git a/third_party/rust/chrono/src/format/scan.rs b/third_party/rust/chrono/src/format/scan.rs new file mode 100644 index 0000000000..7235d67498 --- /dev/null +++ b/third_party/rust/chrono/src/format/scan.rs @@ -0,0 +1,318 @@ +// This is a part of Chrono. +// See README.md and LICENSE.txt for details. + +/*! + * Various scanning routines for the parser. + */ + +#![allow(deprecated)] + +use Weekday; +use super::{ParseResult, TOO_SHORT, INVALID, OUT_OF_RANGE}; + +/// Returns true when two slices are equal case-insensitively (in ASCII). +/// Assumes that the `pattern` is already converted to lower case. +fn equals(s: &str, pattern: &str) -> bool { + let mut xs = s.as_bytes().iter().map(|&c| match c { b'A'...b'Z' => c + 32, _ => c }); + let mut ys = pattern.as_bytes().iter().cloned(); + loop { + match (xs.next(), ys.next()) { + (None, None) => return true, + (None, _) | (_, None) => return false, + (Some(x), Some(y)) if x != y => return false, + _ => (), + } + } +} + +/// Tries to parse the non-negative number from `min` to `max` digits. +/// +/// The absence of digits at all is an unconditional error. +/// More than `max` digits are consumed up to the first `max` digits. +/// Any number that does not fit in `i64` is an error. +#[inline] +pub fn number(s: &str, min: usize, max: usize) -> ParseResult<(&str, i64)> { + assert!(min <= max); + + // We are only interested in ascii numbers, so we can work with the `str` as bytes. We stop on + // the first non-numeric byte, which may be another ascii character or beginning of multi-byte + // UTF-8 character. + let bytes = s.as_bytes(); + if bytes.len() < min { + return Err(TOO_SHORT); + } + + let mut n = 0i64; + for (i, c) in bytes.iter().take(max).cloned().enumerate() { // cloned() = copied() + if c < b'0' || b'9' < c { + if i < min { + return Err(INVALID); + } else { + return Ok((&s[i..], n)); + } + } + + n = match n.checked_mul(10).and_then(|n| n.checked_add((c - b'0') as i64)) { + Some(n) => n, + None => return Err(OUT_OF_RANGE), + }; + } + + Ok((&s[::core::cmp::min(max, bytes.len())..], n)) +} + +/// Tries to consume at least one digits as a fractional second. +/// Returns the number of whole nanoseconds (0--999,999,999). +pub fn nanosecond(s: &str) -> ParseResult<(&str, i64)> { + // record the number of digits consumed for later scaling. + let origlen = s.len(); + let (s, v) = number(s, 1, 9)?; + let consumed = origlen - s.len(); + + // scale the number accordingly. + static SCALE: [i64; 10] = [0, 100_000_000, 10_000_000, 1_000_000, 100_000, 10_000, + 1_000, 100, 10, 1]; + let v = v.checked_mul(SCALE[consumed]).ok_or(OUT_OF_RANGE)?; + + // if there are more than 9 digits, skip next digits. + let s = s.trim_left_matches(|c: char| '0' <= c && c <= '9'); + + Ok((s, v)) +} + +/// Tries to consume a fixed number of digits as a fractional second. +/// Returns the number of whole nanoseconds (0--999,999,999). +pub fn nanosecond_fixed(s: &str, digits: usize) -> ParseResult<(&str, i64)> { + // record the number of digits consumed for later scaling. + let (s, v) = number(s, digits, digits)?; + + // scale the number accordingly. + static SCALE: [i64; 10] = [0, 100_000_000, 10_000_000, 1_000_000, 100_000, 10_000, + 1_000, 100, 10, 1]; + let v = v.checked_mul(SCALE[digits]).ok_or(OUT_OF_RANGE)?; + + Ok((s, v)) +} + +/// Tries to parse the month index (0 through 11) with the first three ASCII letters. +pub fn short_month0(s: &str) -> ParseResult<(&str, u8)> { + if s.len() < 3 { return Err(TOO_SHORT); } + let buf = s.as_bytes(); + let month0 = match (buf[0] | 32, buf[1] | 32, buf[2] | 32) { + (b'j',b'a',b'n') => 0, + (b'f',b'e',b'b') => 1, + (b'm',b'a',b'r') => 2, + (b'a',b'p',b'r') => 3, + (b'm',b'a',b'y') => 4, + (b'j',b'u',b'n') => 5, + (b'j',b'u',b'l') => 6, + (b'a',b'u',b'g') => 7, + (b's',b'e',b'p') => 8, + (b'o',b'c',b't') => 9, + (b'n',b'o',b'v') => 10, + (b'd',b'e',b'c') => 11, + _ => return Err(INVALID) + }; + Ok((&s[3..], month0)) +} + +/// Tries to parse the weekday with the first three ASCII letters. +pub fn short_weekday(s: &str) -> ParseResult<(&str, Weekday)> { + if s.len() < 3 { return Err(TOO_SHORT); } + let buf = s.as_bytes(); + let weekday = match (buf[0] | 32, buf[1] | 32, buf[2] | 32) { + (b'm',b'o',b'n') => Weekday::Mon, + (b't',b'u',b'e') => Weekday::Tue, + (b'w',b'e',b'd') => Weekday::Wed, + (b't',b'h',b'u') => Weekday::Thu, + (b'f',b'r',b'i') => Weekday::Fri, + (b's',b'a',b't') => Weekday::Sat, + (b's',b'u',b'n') => Weekday::Sun, + _ => return Err(INVALID) + }; + Ok((&s[3..], weekday)) +} + +/// Tries to parse the month index (0 through 11) with short or long month names. +/// It prefers long month names to short month names when both are possible. +pub fn short_or_long_month0(s: &str) -> ParseResult<(&str, u8)> { + // lowercased month names, minus first three chars + static LONG_MONTH_SUFFIXES: [&'static str; 12] = + ["uary", "ruary", "ch", "il", "", "e", "y", "ust", "tember", "ober", "ember", "ember"]; + + let (mut s, month0) = short_month0(s)?; + + // tries to consume the suffix if possible + let suffix = LONG_MONTH_SUFFIXES[month0 as usize]; + if s.len() >= suffix.len() && equals(&s[..suffix.len()], suffix) { + s = &s[suffix.len()..]; + } + + Ok((s, month0)) +} + +/// Tries to parse the weekday with short or long weekday names. +/// It prefers long weekday names to short weekday names when both are possible. +pub fn short_or_long_weekday(s: &str) -> ParseResult<(&str, Weekday)> { + // lowercased weekday names, minus first three chars + static LONG_WEEKDAY_SUFFIXES: [&'static str; 7] = + ["day", "sday", "nesday", "rsday", "day", "urday", "day"]; + + let (mut s, weekday) = short_weekday(s)?; + + // tries to consume the suffix if possible + let suffix = LONG_WEEKDAY_SUFFIXES[weekday.num_days_from_monday() as usize]; + if s.len() >= suffix.len() && equals(&s[..suffix.len()], suffix) { + s = &s[suffix.len()..]; + } + + Ok((s, weekday)) +} + +/// Tries to consume exactly one given character. +pub fn char(s: &str, c1: u8) -> ParseResult<&str> { + match s.as_bytes().first() { + Some(&c) if c == c1 => Ok(&s[1..]), + Some(_) => Err(INVALID), + None => Err(TOO_SHORT), + } +} + +/// Tries to consume one or more whitespace. +pub fn space(s: &str) -> ParseResult<&str> { + let s_ = s.trim_left(); + if s_.len() < s.len() { + Ok(s_) + } else if s.is_empty() { + Err(TOO_SHORT) + } else { + Err(INVALID) + } +} + +/// Consumes any number (including zero) of colon or spaces. +pub fn colon_or_space(s: &str) -> ParseResult<&str> { + Ok(s.trim_left_matches(|c: char| c == ':' || c.is_whitespace())) +} + +/// Tries to parse `[-+]\d\d` continued by `\d\d`. Return an offset in seconds if possible. +/// +/// The additional `colon` may be used to parse a mandatory or optional `:` +/// between hours and minutes, and should return either a new suffix or `Err` when parsing fails. +pub fn timezone_offset(s: &str, consume_colon: F) -> ParseResult<(&str, i32)> + where F: FnMut(&str) -> ParseResult<&str> { + timezone_offset_internal(s, consume_colon, false) +} + +fn timezone_offset_internal(mut s: &str, mut consume_colon: F, allow_missing_minutes: bool) +-> ParseResult<(&str, i32)> + where F: FnMut(&str) -> ParseResult<&str> +{ + fn digits(s: &str) -> ParseResult<(u8, u8)> { + let b = s.as_bytes(); + if b.len() < 2 { + Err(TOO_SHORT) + } else { + Ok((b[0], b[1])) + } + } + let negative = match s.as_bytes().first() { + Some(&b'+') => false, + Some(&b'-') => true, + Some(_) => return Err(INVALID), + None => return Err(TOO_SHORT), + }; + s = &s[1..]; + + // hours (00--99) + let hours = match digits(s)? { + (h1 @ b'0'...b'9', h2 @ b'0'...b'9') => i32::from((h1 - b'0') * 10 + (h2 - b'0')), + _ => return Err(INVALID), + }; + s = &s[2..]; + + // colons (and possibly other separators) + s = consume_colon(s)?; + + // minutes (00--59) + // if the next two items are digits then we have to add minutes + let minutes = if let Ok(ds) = digits(s) { + match ds { + (m1 @ b'0'...b'5', m2 @ b'0'...b'9') => i32::from((m1 - b'0') * 10 + (m2 - b'0')), + (b'6'...b'9', b'0'...b'9') => return Err(OUT_OF_RANGE), + _ => return Err(INVALID), + } + } else if allow_missing_minutes { + 0 + } else { + return Err(TOO_SHORT); + }; + s = match s.len() { + len if len >= 2 => &s[2..], + len if len == 0 => s, + _ => return Err(TOO_SHORT), + }; + + let seconds = hours * 3600 + minutes * 60; + Ok((s, if negative {-seconds} else {seconds})) +} + +/// Same to `timezone_offset` but also allows for `z`/`Z` which is same to `+00:00`. +pub fn timezone_offset_zulu(s: &str, colon: F) +-> ParseResult<(&str, i32)> + where F: FnMut(&str) -> ParseResult<&str> +{ + match s.as_bytes().first() { + Some(&b'z') | Some(&b'Z') => Ok((&s[1..], 0)), + _ => timezone_offset(s, colon), + } +} + +/// Same to `timezone_offset` but also allows for `z`/`Z` which is same to +/// `+00:00`, and allows missing minutes entirely. +pub fn timezone_offset_permissive(s: &str, colon: F) +-> ParseResult<(&str, i32)> + where F: FnMut(&str) -> ParseResult<&str> +{ + match s.as_bytes().first() { + Some(&b'z') | Some(&b'Z') => Ok((&s[1..], 0)), + _ => timezone_offset_internal(s, colon, true), + } +} + +/// Same to `timezone_offset` but also allows for RFC 2822 legacy timezones. +/// May return `None` which indicates an insufficient offset data (i.e. `-0000`). +pub fn timezone_offset_2822(s: &str) -> ParseResult<(&str, Option)> { + // tries to parse legacy time zone names + let upto = s.as_bytes().iter().position(|&c| match c { b'a'...b'z' | b'A'...b'Z' => false, + _ => true }) + .unwrap_or_else(|| s.len()); + if upto > 0 { + let name = &s[..upto]; + let s = &s[upto..]; + let offset_hours = |o| Ok((s, Some(o * 3600))); + if equals(name, "gmt") || equals(name, "ut") { + offset_hours(0) + } else if equals(name, "edt") { + offset_hours(-4) + } else if equals(name, "est") || equals(name, "cdt") { + offset_hours(-5) + } else if equals(name, "cst") || equals(name, "mdt") { + offset_hours(-6) + } else if equals(name, "mst") || equals(name, "pdt") { + offset_hours(-7) + } else if equals(name, "pst") { + offset_hours(-8) + } else { + Ok((s, None)) // recommended by RFC 2822: consume but treat it as -0000 + } + } else { + let (s_, offset) = timezone_offset(s, |s| Ok(s))?; + if offset == 0 && s.starts_with('-') { // -0000 is not same to +0000 + Ok((s_, None)) + } else { + Ok((s_, Some(offset))) + } + } +} + -- cgit v1.2.3