Extract common logic for from_str and from_str_radix for `Complex`
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Isaac Carruthers
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41d6a32dba
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42a6ae5353
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@ -963,14 +963,9 @@ impl<T> fmt::Binary for Complex<T> where
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}
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}
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impl<T> FromStr for Complex<T> where
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T: FromStr + Num + Clone
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fn from_str_generic<T, E, F>(s: &str, from: F) -> Result<Complex<T>, ParseComplexError<E>>
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where F: Fn(&str) -> Result<T, E>, T: Clone + Num
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{
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type Err = ParseComplexError<T::Err>;
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/// Parses `a +/- bi`; `ai +/- b`; `a`; or `bi` where `a` and `b` are of type `T`
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fn from_str(s: &str) -> Result<Self, Self::Err>
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{
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let imag = match s.rfind('j') {
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None => 'i',
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_ => 'j'
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@ -1036,7 +1031,7 @@ impl<T> FromStr for Complex<T> where
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}
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// parse re
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let re = try!(T::from_str(re).map_err(ParseComplexError::from_error));
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let re = try!(from(re).map_err(ParseComplexError::from_error));
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// pop imaginary unit off
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let mut im = &im[..im.len()-1];
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@ -1048,9 +1043,20 @@ impl<T> FromStr for Complex<T> where
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}
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// parse im
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let im = try!(T::from_str(im).map_err(ParseComplexError::from_error));
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let im = try!(from(im).map_err(ParseComplexError::from_error));
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Ok(Complex::new(re, im))
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}
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impl<T> FromStr for Complex<T> where
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T: FromStr + Num + Clone
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{
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type Err = ParseComplexError<T::Err>;
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/// Parses `a +/- bi`; `ai +/- b`; `a`; or `bi` where `a` and `b` are of type `T`
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fn from_str(s: &str) -> Result<Self, Self::Err>
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{
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from_str_generic(s, T::from_str)
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}
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}
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@ -1060,86 +1066,8 @@ impl<T: Num + Clone + PartialOrd> Num for Complex<T> {
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/// Parses `a +/- bi`; `ai +/- b`; `a`; or `bi` where `a` and `b` are of type `T`
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fn from_str_radix(s: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr>
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{
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let imag = match s.rfind('j') {
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None => 'i',
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_ => 'j'
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};
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let mut b = String::with_capacity(s.len());
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let mut first = true;
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let char_indices = s.char_indices();
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let mut pc = ' ';
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let mut split_index = s.len();
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for (i, cc) in char_indices {
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if cc == '+' && pc != 'e' && pc != 'E' && i > 0 {
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// ignore '+' if part of an exponent
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if first {
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split_index = i;
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first = false;
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}
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// don't carry '+' over into b
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pc = ' ';
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continue;
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} else if cc == '-' && pc != 'e' && pc != 'E' && i > 0 {
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// ignore '-' if part of an exponent or begins the string
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if first {
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split_index = i;
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first = false;
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}
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// DO carry '-' over into b
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}
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if pc == '-' && cc == ' ' && !first {
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// ignore whitespace between minus sign and next number
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continue;
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}
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if !first {
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b.push(cc);
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}
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pc = cc;
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}
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// split off real and imaginary parts, trim whitespace
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let (a, _) = s.split_at(split_index);
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let a = a.trim_right();
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let mut b = b.trim_left();
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// input was either pure real or pure imaginary
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if b.is_empty() {
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b = match a.ends_with(imag) {
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false => "0i",
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true => "0"
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};
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}
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let re;
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let im;
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if a.ends_with(imag) {
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im = a; re = b;
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} else if b.ends_with(imag) {
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re = a; im = b;
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} else {
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return Err(ParseComplexError::new());
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}
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// parse re
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let re = try!(T::from_str_radix(re, radix).map_err(ParseComplexError::from_error));
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// pop imaginary unit off
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let mut im = &im[..im.len()-1];
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// handle im == "i" or im == "-i"
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if im.is_empty() || im == "+" {
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im = "1";
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} else if im == "-" {
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im = "-1";
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}
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// parse im
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let im = try!(T::from_str_radix(im, radix).map_err(ParseComplexError::from_error));
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Ok(Complex::new(re, im))
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from_str_generic(s, |x| -> Result<T, T::FromStrRadixErr> {
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T::from_str_radix(x, radix) })
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}
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}
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@ -1228,7 +1156,7 @@ mod test {
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use std::f64;
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use std::str::FromStr;
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use traits::{Zero, One, Float};
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use traits::{Zero, One, Float, Num};
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pub const _0_0i : Complex64 = Complex { re: 0.0, im: 0.0 };
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pub const _1_0i : Complex64 = Complex { re: 1.0, im: 0.0 };
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@ -1960,6 +1888,20 @@ mod test {
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test(_05_05i, "0.05e+1j + 50E-2");
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}
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#[test]
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fn test_from_str_radix() {
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fn test(z: Complex64, s: &str, radix: u32) {
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let res: Result<Complex64, <Complex64 as Num>::FromStrRadixErr>
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= Num::from_str_radix(s, radix);
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assert_eq!(res.unwrap(), z)
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}
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test(_4_2i, "4+2i", 10);
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test(Complex::new(15.0, 32.0), "F+20i", 16);
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test(Complex::new(15.0, 32.0), "1111+100000i", 2);
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test(Complex::new(-15.0, -32.0), "-F-20i", 16);
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test(Complex::new(-15.0, -32.0), "-1111-100000i", 2);
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}
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#[test]
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fn test_from_str_fail() {
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fn test(s: &str) {
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