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use crate::{
rbig::{RBig, Relaxed},
repr::Repr,
};
use core::str::FromStr;
use dashu_base::ParseError;
use dashu_int::{IBig, UBig};
impl Repr {
fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseError> {
if let Some(slash) = src.find('/') {
let num = IBig::from_str_radix(&src[..slash], radix)?;
let den = IBig::from_str_radix(&src[slash + 1..], radix)?;
let (sign, den) = den.into_parts();
Ok(Repr {
numerator: num * sign,
denominator: den,
})
} else {
let n = IBig::from_str_radix(src, radix)?;
Ok(Repr {
numerator: n,
denominator: UBig::ONE,
})
}
}
pub fn from_str_with_radix_prefix(src: &str) -> Result<(Self, u32), ParseError> {
if let Some(slash) = src.find('/') {
// first parse the numerator part
let (num, num_radix) = IBig::from_str_with_radix_prefix(&src[..slash])?;
let (den, den_radix) = IBig::from_str_with_radix_default(&src[slash + 1..], num_radix)?;
let (den_sign, den) = den.into_parts();
if num_radix != den_radix {
return Err(ParseError::InconsistentRadix);
}
Ok((
Repr {
numerator: num * den_sign,
denominator: den,
},
num_radix,
))
} else {
let (n, radix) = IBig::from_str_with_radix_prefix(src)?;
Ok((
Repr {
numerator: n,
denominator: UBig::ONE,
},
radix,
))
}
}
}
impl RBig {
/// Convert a string in a given base to [RBig].
///
/// The numerator and the denominator are separated by `/`.
/// `src` may contain an optional `+` prefix.
/// Digits 10-35 are represented by `a-z` or `A-Z`.
///
/// # Examples
/// ```
/// # use dashu_base::ParseError;
/// # use dashu_ratio::RBig;
/// assert_eq!(
/// RBig::from_str_radix("+7ab/-sse", 32)?,
/// RBig::from_parts((-7499).into(), 29582u16.into())
/// );
/// # Ok::<(), ParseError>(())
/// ```
#[inline]
pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseError> {
Repr::from_str_radix(src, radix).map(|repr| RBig(repr.reduce()))
}
/// Convert a string with optional radix prefixes to [RBig], return the
/// parsed integer and radix. If no prefix is present, then the default radix 10
/// will be used for parsing.
///
/// `src` may contain an '+' or `-` prefix before the radix prefix of both the
/// numerator and denominator.
///
/// Allowed prefixes: `0b` for binary, `0o` for octal, `0x` for hexadecimal.
///
/// If the radix prefixes for the numerator and the denominator are not the same,
/// then a ParseError will be returned. The radix prefix for the denominator can be
/// omitted, and the radix for the numerator will used for parsing.
///
/// # Examples
/// ```
/// # use dashu_base::ParseError;
/// # use dashu_ratio::RBig;
/// assert_eq!(RBig::from_str_with_radix_prefix("+0o17/25")?,
/// (RBig::from_parts(0o17.into(), 0o25u8.into()), 8));
/// assert_eq!(RBig::from_str_with_radix_prefix("-0x1f/-0x1e")?,
/// (RBig::from_parts(0x1f.into(), 0x1eu8.into()), 16));
/// # Ok::<(), ParseError>(())
/// ```
#[inline]
pub fn from_str_with_radix_prefix(src: &str) -> Result<(Self, u32), ParseError> {
Repr::from_str_with_radix_prefix(src).map(|(repr, radix)| (Self(repr.reduce()), radix))
}
}
impl FromStr for RBig {
type Err = ParseError;
#[inline]
fn from_str(s: &str) -> Result<Self, ParseError> {
Self::from_str_radix(s, 10)
}
}
impl Relaxed {
/// Convert a string in a given base to [Relaxed].
///
/// See [RBig::from_str_radix] for details.
#[inline]
pub fn from_str_radix(src: &str, radix: u32) -> Result<Self, ParseError> {
Repr::from_str_radix(src, radix).map(|repr| Relaxed(repr.reduce2()))
}
/// Convert a string with optional radix prefixes to [RBig], return the
/// parsed integer and radix.
///
/// See [RBig::from_str_with_radix_prefix] for details.
#[inline]
pub fn from_str_with_radix_prefix(src: &str) -> Result<(Self, u32), ParseError> {
Repr::from_str_with_radix_prefix(src).map(|(repr, radix)| (Self(repr.reduce2()), radix))
}
}
impl FromStr for Relaxed {
type Err = ParseError;
#[inline]
fn from_str(s: &str) -> Result<Self, ParseError> {
Self::from_str_radix(s, 10)
}
}