serde-yaml/src/number.rs

508 lines
14 KiB
Rust

use error::Error;
use serde::de::{Unexpected, Visitor};
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::fmt::{self, Debug, Display};
use std::hash::{Hash, Hasher};
use std::i64;
use std::mem;
use private;
/// Represents a YAML number, whether integer or floating point.
#[derive(Clone, PartialEq, PartialOrd)]
pub struct Number {
n: N,
}
// "N" is a prefix of "NegInt"... this is a false positive.
// https://github.com/Manishearth/rust-clippy/issues/1241
#[cfg_attr(feature = "cargo-clippy", allow(enum_variant_names))]
#[derive(Copy, Clone, Debug, PartialOrd)]
enum N {
PosInt(u64),
/// Always less than zero.
NegInt(i64),
/// May be infinite or NaN.
Float(f64),
}
impl Number {
/// Returns true if the `Number` is an integer between `i64::MIN` and
/// `i64::MAX`.
///
/// For any Number on which `is_i64` returns true, `as_i64` is guaranteed to
/// return the integer value.
///
/// ```edition2018
/// # use std::i64;
/// #
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// #
/// let big = i64::MAX as u64 + 10;
/// let v = yaml(r#"
/// a: 64
/// b: 9223372036854775817
/// c: 256.0
/// "#);
///
/// assert!(v["a"].is_i64());
///
/// // Greater than i64::MAX.
/// assert!(!v["b"].is_i64());
///
/// // Numbers with a decimal point are not considered integers.
/// assert!(!v["c"].is_i64());
/// ```
#[inline]
#[cfg_attr(feature = "cargo-clippy", allow(cast_sign_loss))]
pub fn is_i64(&self) -> bool {
match self.n {
N::PosInt(v) => v <= i64::max_value() as u64,
N::NegInt(_) => true,
N::Float(_) => false,
}
}
/// Returns true if the `Number` is an integer between zero and `u64::MAX`.
///
/// For any Number on which `is_u64` returns true, `as_u64` is guaranteed to
/// return the integer value.
///
/// ```edition2018
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// #
/// let v = yaml(r#"
/// a: 64
/// b: -64
/// c: 256.0
/// "#);
///
/// assert!(v["a"].is_u64());
///
/// // Negative integer.
/// assert!(!v["b"].is_u64());
///
/// // Numbers with a decimal point are not considered integers.
/// assert!(!v["c"].is_u64());
/// ```
#[inline]
pub fn is_u64(&self) -> bool {
match self.n {
N::PosInt(_) => true,
N::NegInt(_) | N::Float(_) => false,
}
}
/// Returns true if the `Number` can be represented by f64.
///
/// For any Number on which `is_f64` returns true, `as_f64` is guaranteed to
/// return the floating point value.
///
/// Currently this function returns true if and only if both `is_i64` and
/// `is_u64` return false but this is not a guarantee in the future.
///
/// ```edition2018
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// #
/// let v = yaml(r#"
/// ---
/// a: 256.0
/// b: 64
/// c: -64
/// "#);
///
/// assert!(v["a"].is_f64());
///
/// // Integers.
/// assert!(!v["b"].is_f64());
/// assert!(!v["c"].is_f64());
/// ```
#[inline]
pub fn is_f64(&self) -> bool {
match self.n {
N::Float(_) => true,
N::PosInt(_) | N::NegInt(_) => false,
}
}
/// If the `Number` is an integer, represent it as i64 if possible. Returns
/// None otherwise.
///
/// ```edition2018
/// # use std::i64;
/// #
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// #
/// let big = i64::MAX as u64 + 10;
/// let v = yaml(r#"
/// ---
/// a: 64
/// b: 9223372036854775817
/// c: 256.0
/// "#);
///
/// assert_eq!(v["a"].as_i64(), Some(64));
/// assert_eq!(v["b"].as_i64(), None);
/// assert_eq!(v["c"].as_i64(), None);
/// ```
#[inline]
pub fn as_i64(&self) -> Option<i64> {
match self.n {
N::PosInt(n) => if n <= i64::max_value() as u64 {
Some(n as i64)
} else {
None
},
N::NegInt(n) => Some(n),
N::Float(_) => None,
}
}
/// If the `Number` is an integer, represent it as u64 if possible. Returns
/// None otherwise.
///
/// ```edition2018
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// #
/// let v = yaml(r#"
/// ---
/// a: 64
/// b: -64
/// c: 256.0
/// "#);
///
/// assert_eq!(v["a"].as_u64(), Some(64));
/// assert_eq!(v["b"].as_u64(), None);
/// assert_eq!(v["c"].as_u64(), None);
/// ```
#[inline]
pub fn as_u64(&self) -> Option<u64> {
match self.n {
N::PosInt(n) => Some(n),
N::NegInt(_) | N::Float(_) => None,
}
}
/// Represents the number as f64 if possible. Returns None otherwise.
///
/// ```edition2018
/// #
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// let v = yaml(r#"
/// ---
/// a: 256.0
/// b: 64
/// c: -64
/// "#);
///
/// assert_eq!(v["a"].as_f64(), Some(256.0));
/// assert_eq!(v["b"].as_f64(), Some(64.0));
/// assert_eq!(v["c"].as_f64(), Some(-64.0));
/// ```
///
/// ```edition2018
/// # use std::f64;
/// # fn yaml(i: &str) -> serde_yaml::Value { serde_yaml::from_str(i).unwrap() }
/// assert_eq!(yaml("inf").as_f64(), Some(f64::INFINITY));
/// assert_eq!(yaml("-inf").as_f64(), Some(f64::NEG_INFINITY));
/// assert!(yaml("NaN").as_f64().unwrap().is_nan());
/// ```
#[inline]
pub fn as_f64(&self) -> Option<f64> {
match self.n {
N::PosInt(n) => Some(n as f64),
N::NegInt(n) => Some(n as f64),
N::Float(n) => Some(n),
}
}
/// Returns true if this value is NaN and false otherwise.
///
/// ```edition2018
/// # use std::f64;
/// #
/// # use serde_yaml::Number;
/// #
/// assert!(!Number::from(256.0).is_nan());
///
/// assert!(Number::from(f64::NAN).is_nan());
///
/// assert!(!Number::from(f64::INFINITY).is_nan());
///
/// assert!(!Number::from(f64::NEG_INFINITY).is_nan());
///
/// assert!(!Number::from(1).is_nan());
/// ```
#[inline]
pub fn is_nan(&self) -> bool {
match self.n {
N::PosInt(_) | N::NegInt(_) => false,
N::Float(f) => f.is_nan(),
}
}
/// Returns true if this value is positive infinity or negative infinity and
/// false otherwise.
///
/// ```edition2018
/// # use std::f64;
/// #
/// # use serde_yaml::Number;
/// #
/// assert!(!Number::from(256.0).is_infinite());
///
/// assert!(!Number::from(f64::NAN).is_infinite());
///
/// assert!(Number::from(f64::INFINITY).is_infinite());
///
/// assert!(Number::from(f64::NEG_INFINITY).is_infinite());
///
/// assert!(!Number::from(1).is_infinite());
/// ```
#[inline]
pub fn is_infinite(&self) -> bool {
match self.n {
N::PosInt(_) | N::NegInt(_) => false,
N::Float(f) => f.is_infinite(),
}
}
/// Returns true if this number is neither infinite nor NaN.
///
/// ```edition2018
/// # use std::f64;
/// #
/// # use serde_yaml::Number;
/// #
/// assert!(Number::from(256.0).is_finite());
///
/// assert!(!Number::from(f64::NAN).is_finite());
///
/// assert!(!Number::from(f64::INFINITY).is_finite());
///
/// assert!(!Number::from(f64::NEG_INFINITY).is_finite());
///
/// assert!(Number::from(1).is_finite());
/// ```
#[inline]
pub fn is_finite(&self) -> bool {
match self.n {
N::PosInt(_) | N::NegInt(_) => true,
N::Float(f) => f.is_finite(),
}
}
}
impl fmt::Display for Number {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
match self.n {
N::PosInt(i) => Display::fmt(&i, formatter),
N::NegInt(i) => Display::fmt(&i, formatter),
N::Float(f) if f.is_nan() => formatter.write_str(".nan"),
N::Float(f) if f.is_infinite() => {
if f.is_sign_negative() {
formatter.write_str("-.inf")
} else {
formatter.write_str(".inf")
}
}
N::Float(f) => Display::fmt(&f, formatter),
}
}
}
impl Debug for Number {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
Debug::fmt(&self.n, formatter)
}
}
impl PartialEq for N {
fn eq(&self, other: &N) -> bool {
match (*self, *other) {
(N::PosInt(a), N::PosInt(b)) => a == b,
(N::NegInt(a), N::NegInt(b)) => a == b,
(N::Float(a), N::Float(b)) => {
if a.is_nan() && b.is_nan() {
// Compare NaN for bitwise equality.
// The unsafe code is equivalent to f64::to_bits which was
// stabilized in 1.20.0.
let a = unsafe { mem::transmute::<f64, u64>(a) };
let b = unsafe { mem::transmute::<f64, u64>(b) };
a == b
} else {
a == b
}
}
_ => false,
}
}
}
impl Serialize for Number {
#[inline]
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
match self.n {
N::PosInt(i) => serializer.serialize_u64(i),
N::NegInt(i) => serializer.serialize_i64(i),
N::Float(f) => serializer.serialize_f64(f),
}
}
}
impl<'de> Deserialize<'de> for Number {
#[inline]
fn deserialize<D>(deserializer: D) -> Result<Number, D::Error>
where
D: Deserializer<'de>,
{
struct NumberVisitor;
impl<'de> Visitor<'de> for NumberVisitor {
type Value = Number;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a number")
}
#[inline]
fn visit_i64<E>(self, value: i64) -> Result<Number, E> {
Ok(value.into())
}
#[inline]
fn visit_u64<E>(self, value: u64) -> Result<Number, E> {
Ok(value.into())
}
#[inline]
fn visit_f64<E>(self, value: f64) -> Result<Number, E> {
Ok(value.into())
}
}
deserializer.deserialize_any(NumberVisitor)
}
}
impl<'de> Deserializer<'de> for Number {
type Error = Error;
#[inline]
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self.n {
N::PosInt(i) => visitor.visit_u64(i),
N::NegInt(i) => visitor.visit_i64(i),
N::Float(f) => visitor.visit_f64(f),
}
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
bytes byte_buf option unit unit_struct newtype_struct seq tuple
tuple_struct map struct enum identifier ignored_any
}
}
impl<'de, 'a> Deserializer<'de> for &'a Number {
type Error = Error;
#[inline]
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self.n {
N::PosInt(i) => visitor.visit_u64(i),
N::NegInt(i) => visitor.visit_i64(i),
N::Float(f) => visitor.visit_f64(f),
}
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
bytes byte_buf option unit unit_struct newtype_struct seq tuple
tuple_struct map struct enum identifier ignored_any
}
}
macro_rules! from_signed {
($($signed_ty:ident)*) => {
$(
impl From<$signed_ty> for Number {
#[inline]
#[cfg_attr(feature = "cargo-clippy", allow(cast_sign_loss))]
fn from(i: $signed_ty) -> Self {
if i < 0 {
Number { n: N::NegInt(i as i64) }
} else {
Number { n: N::PosInt(i as u64) }
}
}
}
)*
};
}
macro_rules! from_unsigned {
($($unsigned_ty:ident)*) => {
$(
impl From<$unsigned_ty> for Number {
#[inline]
fn from(u: $unsigned_ty) -> Self {
Number { n: N::PosInt(u as u64) }
}
}
)*
};
}
macro_rules! from_float {
($($float_ty:ident)*) => {
$(
impl From<$float_ty> for Number {
#[inline]
fn from(f: $float_ty) -> Self {
Number { n: N::Float(f as f64) }
}
}
)*
}
}
from_signed!(i8 i16 i32 i64 isize);
from_unsigned!(u8 u16 u32 u64 usize);
from_float!(f32 f64);
// This is fine, because we don't _really_ implement hash for floats
// all other hash functions should work as expected
#[cfg_attr(feature = "cargo-clippy", allow(derive_hash_xor_eq))]
impl Hash for Number {
fn hash<H: Hasher>(&self, state: &mut H) {
match self.n {
N::Float(_) => {
// you should feel bad for using f64 as a map key
3.hash(state)
}
N::PosInt(u) => u.hash(state),
N::NegInt(i) => i.hash(state),
}
}
}
impl private {
pub fn number_unexpected(number: &Number) -> Unexpected {
match number.n {
N::PosInt(u) => Unexpected::Unsigned(u),
N::NegInt(i) => Unexpected::Signed(i),
N::Float(f) => Unexpected::Float(f),
}
}
}