Allows for arbitrary spacing between operands when parsing Complex
This commit is contained in:
Alan Liddell
parent
e5e8266009
commit
ac746c2a5d
|
|
@ -750,42 +750,64 @@ impl<T> FromStr for Complex<T> where
|
|||
/// Parses `a +/- bi`; `ai +/- b`; `a`; or `bi` where `a` and `b` are of type `T`
|
||||
fn from_str(s: &str) -> Result<Complex<T>, ParseComplexError>
|
||||
{
|
||||
// first try to split on " + "
|
||||
let mut split_p = s.splitn(2, " + ");
|
||||
let imag = 'i';
|
||||
|
||||
let mut a = match split_p.next() {
|
||||
None => return Err(ParseComplexError { kind: ComplexErrorKind::ParseError }),
|
||||
Some(s) => s.trim_right().to_string()
|
||||
};
|
||||
let mut a = String::with_capacity(s.len());
|
||||
let mut b = String::with_capacity(s.len());
|
||||
|
||||
let mut b = match split_p.next() {
|
||||
// no second item could mean we need to split on " - " instead
|
||||
None => {
|
||||
let mut split_m = s.splitn(2, " - ");
|
||||
let mut first = true;
|
||||
let mut char_indices = s.char_indices();
|
||||
let mut pc = ' ';
|
||||
|
||||
a = match split_m.next() {
|
||||
None => return Err(ParseComplexError { kind: ComplexErrorKind::ParseError }),
|
||||
Some(s) => s.trim_right().to_string()
|
||||
};
|
||||
|
||||
let c = match split_m.next() {
|
||||
None => {
|
||||
// if `a` is imaginary, let `b` be real (and vice versa)
|
||||
match a.rfind('i') {
|
||||
None => "0i".to_string(),
|
||||
_ => "0".to_string()
|
||||
loop {
|
||||
match char_indices.next() {
|
||||
Some(t) => {
|
||||
let i = t.0;
|
||||
let cc = t.1;
|
||||
if cc == '+' {
|
||||
// handle exponents
|
||||
if pc != 'e' && pc != 'E' {
|
||||
first = false;
|
||||
// don't carry '+' over into b
|
||||
pc = ' ';
|
||||
continue;
|
||||
}
|
||||
} else if cc == '-' {
|
||||
// handle exponents and negative numbers
|
||||
if i > 0 && pc != 'e' && pc != 'E' {
|
||||
first = false;
|
||||
// DO carry '-' over into b
|
||||
}
|
||||
}
|
||||
Some(s) => {
|
||||
"-".to_string() + s.trim_left()
|
||||
}
|
||||
};
|
||||
c
|
||||
},
|
||||
Some(s) => s.trim_left().to_string()
|
||||
};
|
||||
|
||||
let re = match a.rfind('i') {
|
||||
if !first && cc == ' ' && pc == '-' {
|
||||
// ignore whitespace between minus sign and next number
|
||||
continue;
|
||||
}
|
||||
|
||||
if first {
|
||||
a.push(cc);
|
||||
} else {
|
||||
b.push(cc);
|
||||
}
|
||||
|
||||
pc = cc;
|
||||
},
|
||||
None => break,
|
||||
}
|
||||
}
|
||||
|
||||
a = a.trim_right().to_string();
|
||||
b = b.trim_left().to_string();
|
||||
|
||||
if b.is_empty() {
|
||||
b = match a.rfind(imag) {
|
||||
None => "0i".to_string(),
|
||||
_ => "0".to_string()
|
||||
};
|
||||
}
|
||||
|
||||
let re = match a.rfind(imag) {
|
||||
None => {
|
||||
try!(T::from_str(&a)
|
||||
.map_err(|_| ParseComplexError { kind: ComplexErrorKind::ParseError }))
|
||||
|
|
@ -796,20 +818,20 @@ impl<T> FromStr for Complex<T> where
|
|||
}
|
||||
};
|
||||
|
||||
let im = match a.rfind('i') {
|
||||
let im = match a.rfind(imag) {
|
||||
None => {
|
||||
// a is real
|
||||
match b.pop() {
|
||||
// b was empty
|
||||
None => return Err(ParseComplexError { kind: ComplexErrorKind::ParseError }),
|
||||
Some(c) => {
|
||||
if c == 'i' {
|
||||
if c == imag {
|
||||
// b is imaginary
|
||||
if b.is_empty() {
|
||||
// b was just 'i'
|
||||
// b was just 'imag'
|
||||
b = "1".to_string();
|
||||
} else if b == "-" {
|
||||
// b was just '-i'
|
||||
// b was just '-imag'
|
||||
b = "-1".to_string();
|
||||
}
|
||||
} else {
|
||||
|
|
@ -823,17 +845,17 @@ impl<T> FromStr for Complex<T> where
|
|||
.map_err(|_| ParseComplexError { kind: ComplexErrorKind::ParseError }))
|
||||
},
|
||||
_ => {
|
||||
// a contains an 'i'
|
||||
// a contains imag
|
||||
match a.pop() {
|
||||
None => return Err(ParseComplexError { kind: ComplexErrorKind::ParseError }),
|
||||
Some(c) => {
|
||||
if c == 'i' {
|
||||
if c == imag {
|
||||
// a is imaginary
|
||||
if a.is_empty() {
|
||||
// a was just 'i'
|
||||
// a was just 'imag'
|
||||
a = "1".to_string();
|
||||
} else if a == "-" {
|
||||
// a was just '-i'
|
||||
// a was just '-imag'
|
||||
a = "-1".to_string();
|
||||
}
|
||||
} else {
|
||||
|
|
@ -1553,25 +1575,38 @@ mod test {
|
|||
test(_0_0i, "-0".to_string());
|
||||
test(_0_0i, "-0i".to_string());
|
||||
test(_0_0i, "0 + 0i".to_string());
|
||||
test(_0_0i, "0+0i".to_string());
|
||||
test(_0_0i, "0 - 0i".to_string());
|
||||
test(_0_0i, "0-0i".to_string());
|
||||
|
||||
test(_1_0i, "1".to_string());
|
||||
test(_1_0i, "1 + 0i".to_string());
|
||||
test(_1_0i, "1+0i".to_string());
|
||||
test(_1_0i, "1 - 0i".to_string());
|
||||
test(_1_0i, "1-0i".to_string());
|
||||
|
||||
test(_1_1i, "1 + i".to_string());
|
||||
test(_1_1i, "1+i".to_string());
|
||||
test(_1_1i, "1 + 1i".to_string());
|
||||
test(_1_1i, "1+1i".to_string());
|
||||
|
||||
test(_0_1i, "i".to_string());
|
||||
test(_0_1i, "1i".to_string());
|
||||
test(_0_1i, "0 + i".to_string());
|
||||
test(_0_1i, "0+i".to_string());
|
||||
test(_0_1i, "-0 + i".to_string());
|
||||
test(_0_1i, "-0+i".to_string());
|
||||
test(_0_1i, "0 + 1i".to_string());
|
||||
test(_0_1i, "0+1i".to_string());
|
||||
test(_0_1i, "-0 + 1i".to_string());
|
||||
test(_0_1i, "-0+1i".to_string());
|
||||
|
||||
test(_neg1_1i, "-1 + i".to_string());
|
||||
test(_neg1_1i, "-1+i".to_string());
|
||||
test(_neg1_1i, "-1 + 1i".to_string());
|
||||
test(_neg1_1i, "-1+1i".to_string());
|
||||
|
||||
test(_05_05i, "0.5 + 0.5i".to_string());
|
||||
test(_05_05i, "0.5+0.5i".to_string());
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue