use std::cmp::Ordering; use std::convert::Into; use std::fmt; use std::num::NonZeroU32; use std::ops::Deref; use std::str::FromStr; use crate::helpers::make_4byte_bytes; use crate::Error; /// A tiny string that is from 1 to 4 non-NUL ASCII characters. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "Test".parse() /// .expect("Failed to parse."); /// /// assert_eq!(s1, "Test"); /// assert!(s1.is_ascii_alphabetic()); /// ``` #[derive(Copy, Clone, PartialEq, Eq, Hash)] pub struct TinyStr4(NonZeroU32); impl TinyStr4 { /// Creates a TinyStr4 from a byte slice. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1 = TinyStr4::from_bytes("Test".as_bytes()) /// .expect("Failed to parse."); /// /// assert_eq!(s1, "Test"); /// ``` #[inline(always)] pub fn from_bytes(bytes: &[u8]) -> Result { unsafe { match bytes.len() { 1 => make_4byte_bytes(bytes, 1, 0x80).map(Self), 2 => make_4byte_bytes(bytes, 2, 0x8080).map(Self), 3 => make_4byte_bytes(bytes, 3, 0x0080_8080).map(Self), 4 => make_4byte_bytes(bytes, 4, 0x8080_8080).map(Self), _ => Err(Error::InvalidSize), } } } /// An unsafe constructor intended for cases where the consumer /// guarantees that the input is a little endian integer which /// is a correct representation of a `TinyStr4` string. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "Test".parse() /// .expect("Failed to parse."); /// /// let num: u32 = s1.into(); /// /// let s2 = unsafe { TinyStr4::new_unchecked(num) }; /// /// assert_eq!(s1, s2); /// assert_eq!(s2.as_str(), "Test"); /// ``` #[inline(always)] pub const unsafe fn new_unchecked(text: u32) -> Self { Self(NonZeroU32::new_unchecked(u32::from_le(text))) } /// Extracts a string slice containing the entire `TinyStr4`. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "Test".parse() /// .expect("Failed to parse."); /// /// assert_eq!(s1.as_str(), "Test"); /// ``` #[inline(always)] pub fn as_str(&self) -> &str { self.deref() } /// Checks if the value is composed of ASCII alphabetic characters: /// /// * U+0041 'A' ..= U+005A 'Z', or /// * U+0061 'a' ..= U+007A 'z'. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "Test".parse() /// .expect("Failed to parse."); /// let s2: TinyStr4 = "Te3t".parse() /// .expect("Failed to parse."); /// /// assert!(s1.is_ascii_alphabetic()); /// assert!(!s2.is_ascii_alphabetic()); /// ``` pub fn is_ascii_alphabetic(self) -> bool { let word = self.0.get(); let mask = (word + 0x7f7f_7f7f) & 0x8080_8080; let lower = word | 0x2020_2020; let alpha = !(lower + 0x1f1f_1f1f) | (lower + 0x0505_0505); (alpha & mask) == 0 } /// Checks if the value is composed of ASCII alphanumeric characters: /// /// * U+0041 'A' ..= U+005A 'Z', or /// * U+0061 'a' ..= U+007A 'z', or /// * U+0030 '0' ..= U+0039 '9'. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "A15b".parse() /// .expect("Failed to parse."); /// let s2: TinyStr4 = "[3@w".parse() /// .expect("Failed to parse."); /// /// assert!(s1.is_ascii_alphanumeric()); /// assert!(!s2.is_ascii_alphanumeric()); /// ``` pub fn is_ascii_alphanumeric(self) -> bool { let word = self.0.get(); let mask = (word + 0x7f7f_7f7f) & 0x8080_8080; let numeric = !(word + 0x5050_5050) | (word + 0x4646_4646); let lower = word | 0x2020_2020; let alpha = !(lower + 0x1f1f_1f1f) | (lower + 0x0505_0505); (alpha & numeric & mask) == 0 } /// Checks if the value is composed of ASCII decimal digits: /// /// * U+0030 '0' ..= U+0039 '9'. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "312".parse() /// .expect("Failed to parse."); /// let s2: TinyStr4 = "3d".parse() /// .expect("Failed to parse."); /// /// assert!(s1.is_ascii_numeric()); /// assert!(!s2.is_ascii_numeric()); /// ``` pub fn is_ascii_numeric(self) -> bool { let word = self.0.get(); let mask = (word + 0x7f7f_7f7f) & 0x8080_8080; let numeric = !(word + 0x5050_5050) | (word + 0x4646_4646); (numeric & mask) == 0 } /// Converts this type to its ASCII lower case equivalent in-place. /// /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', other characters are unchanged. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "TeS3".parse() /// .expect("Failed to parse."); /// /// assert_eq!(s1.to_ascii_lowercase(), "tes3"); /// ``` pub fn to_ascii_lowercase(self) -> Self { let word = self.0.get(); let result = word | (((word + 0x3f3f_3f3f) & !(word + 0x2525_2525) & 0x8080_8080) >> 2); unsafe { Self(NonZeroU32::new_unchecked(result)) } } /// Converts this type to its ASCII title case equivalent in-place. /// /// First character, if is an ASCII letter 'a' to 'z' is mapped to 'A' to 'Z', /// other characters are unchanged. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "test".parse() /// .expect("Failed to parse."); /// /// assert_eq!(s1.to_ascii_titlecase(), "Test"); /// ``` pub fn to_ascii_titlecase(self) -> Self { let word = self.0.get().to_le(); let mask = ((word + 0x3f3f_3f1f) & !(word + 0x2525_2505) & 0x8080_8080) >> 2; let result = (word | mask) & !(0x20 & mask); unsafe { Self(NonZeroU32::new_unchecked(u32::from_le(result))) } } /// Converts this type to its ASCII upper case equivalent in-place. /// /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', other characters are unchanged. /// /// # Examples /// /// ``` /// use tinystr::TinyStr4; /// /// let s1: TinyStr4 = "Tes3".parse() /// .expect("Failed to parse."); /// /// assert_eq!(s1.to_ascii_uppercase(), "TES3"); /// ``` pub fn to_ascii_uppercase(self) -> Self { let word = self.0.get(); let result = word & !(((word + 0x1f1f_1f1f) & !(word + 0x0505_0505) & 0x8080_8080) >> 2); unsafe { Self(NonZeroU32::new_unchecked(result)) } } } impl fmt::Display for TinyStr4 { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", self.deref()) } } impl fmt::Debug for TinyStr4 { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?}", self.deref()) } } impl Deref for TinyStr4 { type Target = str; #[inline(always)] fn deref(&self) -> &str { // Again, could use #cfg to hand-roll a big-endian implementation. let word = self.0.get().to_le(); let len = (4 - word.leading_zeros() / 8) as usize; unsafe { let slice = core::slice::from_raw_parts(&self.0 as *const _ as *const u8, len); std::str::from_utf8_unchecked(slice) } } } impl PartialEq<&str> for TinyStr4 { fn eq(&self, other: &&str) -> bool { self.deref() == *other } } impl PartialOrd for TinyStr4 { fn partial_cmp(&self, other: &Self) -> Option { Some(self.cmp(other)) } } impl Ord for TinyStr4 { fn cmp(&self, other: &Self) -> Ordering { self.0.get().to_be().cmp(&other.0.get().to_be()) } } impl FromStr for TinyStr4 { type Err = Error; #[inline(always)] fn from_str(text: &str) -> Result { Self::from_bytes(text.as_bytes()) } } impl Into for TinyStr4 { fn into(self) -> u32 { self.0.get().to_le() } }