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Allow unary `+` when parsing BigInt from strings

This commit is contained in:
Mike MacDonald (crazymykl) 2016-02-20 20:40:59 -05:00
parent 69f11004f6
commit 9def836603
1 changed files with 20 additions and 1 deletions
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21
src/bigint.rs
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@ -366,6 +366,12 @@ impl Num for BigUint {
/// Creates and initializes a `BigUint`. /// Creates and initializes a `BigUint`.
fn from_str_radix(s: &str, radix: u32) -> Result<BigUint, ParseBigIntError> { fn from_str_radix(s: &str, radix: u32) -> Result<BigUint, ParseBigIntError> {
assert!(2 <= radix && radix <= 36, "The radix must be within 2...36"); assert!(2 <= radix && radix <= 36, "The radix must be within 2...36");
let mut s = s;
if s.starts_with('+') {
let tail = &s[1..];
if !tail.starts_with('+') { s = tail }
}
if s.is_empty() { if s.is_empty() {
// create ParseIntError::Empty // create ParseIntError::Empty
let e = u64::from_str_radix(s, radix).unwrap_err(); let e = u64::from_str_radix(s, radix).unwrap_err();
@ -1891,7 +1897,11 @@ impl Num for BigInt {
/// Creates and initializes a BigInt. /// Creates and initializes a BigInt.
#[inline] #[inline]
fn from_str_radix(mut s: &str, radix: u32) -> Result<BigInt, ParseBigIntError> { fn from_str_radix(mut s: &str, radix: u32) -> Result<BigInt, ParseBigIntError> {
let sign = if s.starts_with('-') { s = &s[1..]; Minus } else { Plus }; let sign = if s.starts_with('-') {
let tail = &s[1..];
if !tail.starts_with('+') { s = tail }
Minus
} else { Plus };
let bu = try!(BigUint::from_str_radix(s, radix)); let bu = try!(BigUint::from_str_radix(s, radix));
Ok(BigInt::from_biguint(sign, bu)) Ok(BigInt::from_biguint(sign, bu))
} }
@ -3743,6 +3753,10 @@ mod biguint_tests {
assert_eq!(zed, None); assert_eq!(zed, None);
let blank = BigUint::from_str_radix("_", 2).ok(); let blank = BigUint::from_str_radix("_", 2).ok();
assert_eq!(blank, None); assert_eq!(blank, None);
let plus_one = BigUint::from_str_radix("+1", 10).ok();
assert_eq!(plus_one, Some(BigUint::from_slice(&[1])));
let plus_plus_one = BigUint::from_str_radix("++1", 10).ok();
assert_eq!(plus_plus_one, None);
let minus_one = BigUint::from_str_radix("-1", 10).ok(); let minus_one = BigUint::from_str_radix("-1", 10).ok();
assert_eq!(minus_one, None); assert_eq!(minus_one, None);
} }
@ -4767,6 +4781,11 @@ mod bigint_tests {
check("0", Some(0)); check("0", Some(0));
check("-1", Some(-1)); check("-1", Some(-1));
check("-10", Some(-10)); check("-10", Some(-10));
check("+10", Some(10));
check("--7", None);
check("++5", None);
check("+-9", None);
check("-+3", None);
check("Z", None); check("Z", None);
check("_", None); check("_", None);