//! Structured values.
//!
//! This module defines the [`Value`] type and supporting APIs for
//! capturing and serializing them.
use std::fmt;
pub use crate::kv::Error;
/// A type that can be converted into a [`Value`](struct.Value.html).
pub trait ToValue {
/// Perform the conversion.
fn to_value(&self) -> Value;
}
impl<'a, T> ToValue for &'a T
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl<'v> ToValue for Value<'v> {
fn to_value(&self) -> Value {
Value {
inner: self.inner.clone(),
}
}
}
/// A value in a key-value.
///
/// Values are an anonymous bag containing some structured datum.
///
/// # Capturing values
///
/// There are a few ways to capture a value:
///
/// - Using the `Value::from_*` methods.
/// - Using the `ToValue` trait.
/// - Using the standard `From` trait.
///
/// ## Using the `Value::from_*` methods
///
/// `Value` offers a few constructor methods that capture values of different kinds.
///
/// ```
/// use log::kv::Value;
///
/// let value = Value::from_debug(&42i32);
///
/// assert_eq!(None, value.to_i64());
/// ```
///
/// ## Using the `ToValue` trait
///
/// The `ToValue` trait can be used to capture values generically.
/// It's the bound used by `Source`.
///
/// ```
/// # use log::kv::ToValue;
/// let value = 42i32.to_value();
///
/// assert_eq!(Some(42), value.to_i64());
/// ```
///
/// ## Using the standard `From` trait
///
/// Standard types that implement `ToValue` also implement `From`.
///
/// ```
/// use log::kv::Value;
///
/// let value = Value::from(42i32);
///
/// assert_eq!(Some(42), value.to_i64());
/// ```
///
/// # Data model
///
/// Values can hold one of a number of types:
///
/// - **Null:** The absence of any other meaningful value. Note that
/// `Some(Value::null())` is not the same as `None`. The former is
/// `null` while the latter is `undefined`. This is important to be
/// able to tell the difference between a key-value that was logged,
/// but its value was empty (`Some(Value::null())`) and a key-value
/// that was never logged at all (`None`).
/// - **Strings:** `str`, `char`.
/// - **Booleans:** `bool`.
/// - **Integers:** `u8`-`u128`, `i8`-`i128`, `NonZero*`.
/// - **Floating point numbers:** `f32`-`f64`.
/// - **Errors:** `dyn (Error + 'static)`.
/// - **`serde`:** Any type in `serde`'s data model.
/// - **`sval`:** Any type in `sval`'s data model.
///
/// # Serialization
///
/// Values provide a number of ways to be serialized.
///
/// For basic types the [`Value::visit`] method can be used to extract the
/// underlying typed value. However this is limited in the amount of types
/// supported (see the [`VisitValue`] trait methods).
///
/// For more complex types one of the following traits can be used:
/// * `sval::Value`, requires the `kv_sval` feature.
/// * `serde::Serialize`, requires the `kv_serde` feature.
///
/// You don't need a visitor to serialize values through `serde` or `sval`.
///
/// A value can always be serialized using any supported framework, regardless
/// of how it was captured. If, for example, a value was captured using its
/// `Display` implementation, it will serialize through `serde` as a string. If it was
/// captured as a struct using `serde`, it will also serialize as a struct
/// through `sval`, or can be formatted using a `Debug`-compatible representation.
pub struct Value<'v> {
inner: inner::Inner<'v>,
}
impl<'v> Value<'v> {
/// Get a value from a type implementing `ToValue`.
pub fn from_any<T>(value: &'v T) -> Self
where
T: ToValue,
{
value.to_value()
}
/// Get a value from a type implementing `std::fmt::Debug`.
pub fn from_debug<T>(value: &'v T) -> Self
where
T: fmt::Debug,
{
Value {
inner: inner::Inner::from_debug(value),
}
}
/// Get a value from a type implementing `std::fmt::Display`.
pub fn from_display<T>(value: &'v T) -> Self
where
T: fmt::Display,
{
Value {
inner: inner::Inner::from_display(value),
}
}
/// Get a value from a type implementing `serde::Serialize`.
#[cfg(feature = "kv_serde")]
pub fn from_serde<T>(value: &'v T) -> Self
where
T: serde::Serialize,
{
Value {
inner: inner::Inner::from_serde1(value),
}
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_sval")]
pub fn from_sval<T>(value: &'v T) -> Self
where
T: sval::Value,
{
Value {
inner: inner::Inner::from_sval2(value),
}
}
/// Get a value from a dynamic `std::fmt::Debug`.
pub fn from_dyn_debug(value: &'v dyn fmt::Debug) -> Self {
Value {
inner: inner::Inner::from_dyn_debug(value),
}
}
/// Get a value from a dynamic `std::fmt::Display`.
pub fn from_dyn_display(value: &'v dyn fmt::Display) -> Self {
Value {
inner: inner::Inner::from_dyn_display(value),
}
}
/// Get a value from a dynamic error.
#[cfg(feature = "kv_std")]
pub fn from_dyn_error(err: &'v (dyn std::error::Error + 'static)) -> Self {
Value {
inner: inner::Inner::from_dyn_error(err),
}
}
/// Get a `null` value.
pub fn null() -> Self {
Value {
inner: inner::Inner::empty(),
}
}
/// Get a value from an internal primitive.
fn from_inner<T>(value: T) -> Self
where
T: Into<inner::Inner<'v>>,
{
Value {
inner: value.into(),
}
}
/// Inspect this value using a simple visitor.
///
/// When the `kv_serde` or `kv_sval` features are enabled, you can also
/// serialize a value using its `Serialize` or `Value` implementation.
pub fn visit(&self, visitor: impl VisitValue<'v>) -> Result<(), Error> {
inner::visit(&self.inner, visitor)
}
}
impl<'v> fmt::Debug for Value<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&self.inner, f)
}
}
impl<'v> fmt::Display for Value<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.inner, f)
}
}
#[cfg(feature = "kv_serde")]
impl<'v> serde::Serialize for Value<'v> {
fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
self.inner.serialize(s)
}
}
#[cfg(feature = "kv_sval")]
impl<'v> sval::Value for Value<'v> {
fn stream<'sval, S: sval::Stream<'sval> + ?Sized>(&'sval self, stream: &mut S) -> sval::Result {
sval::Value::stream(&self.inner, stream)
}
}
#[cfg(feature = "kv_sval")]
impl<'v> sval_ref::ValueRef<'v> for Value<'v> {
fn stream_ref<S: sval::Stream<'v> + ?Sized>(&self, stream: &mut S) -> sval::Result {
sval_ref::ValueRef::stream_ref(&self.inner, stream)
}
}
impl ToValue for str {
fn to_value(&self) -> Value {
Value::from(self)
}
}
impl<'v> From<&'v str> for Value<'v> {
fn from(value: &'v str) -> Self {
Value::from_inner(value)
}
}
impl ToValue for () {
fn to_value(&self) -> Value {
Value::from_inner(())
}
}
impl<T> ToValue for Option<T>
where
T: ToValue,
{
fn to_value(&self) -> Value {
match *self {
Some(ref value) => value.to_value(),
None => Value::from_inner(()),
}
}
}
macro_rules! impl_to_value_primitive {
($($into_ty:ty,)*) => {
$(
impl ToValue for $into_ty {
fn to_value(&self) -> Value {
Value::from(*self)
}
}
impl<'v> From<$into_ty> for Value<'v> {
fn from(value: $into_ty) -> Self {
Value::from_inner(value)
}
}
impl<'v> From<&'v $into_ty> for Value<'v> {
fn from(value: &'v $into_ty) -> Self {
Value::from_inner(*value)
}
}
)*
};
}
macro_rules! impl_to_value_nonzero_primitive {
($($into_ty:ident,)*) => {
$(
impl ToValue for std::num::$into_ty {
fn to_value(&self) -> Value {
Value::from(self.get())
}
}
impl<'v> From<std::num::$into_ty> for Value<'v> {
fn from(value: std::num::$into_ty) -> Self {
Value::from(value.get())
}
}
impl<'v> From<&'v std::num::$into_ty> for Value<'v> {
fn from(value: &'v std::num::$into_ty) -> Self {
Value::from(value.get())
}
}
)*
};
}
macro_rules! impl_value_to_primitive {
($(#[doc = $doc:tt] $into_name:ident -> $into_ty:ty,)*) => {
impl<'v> Value<'v> {
$(
#[doc = $doc]
pub fn $into_name(&self) -> Option<$into_ty> {
self.inner.$into_name()
}
)*
}
}
}
impl_to_value_primitive![
usize, u8, u16, u32, u64, u128, isize, i8, i16, i32, i64, i128, f32, f64, char, bool,
];
#[rustfmt::skip]
impl_to_value_nonzero_primitive![
NonZeroUsize, NonZeroU8, NonZeroU16, NonZeroU32, NonZeroU64, NonZeroU128,
NonZeroIsize, NonZeroI8, NonZeroI16, NonZeroI32, NonZeroI64, NonZeroI128,
];
impl_value_to_primitive![
#[doc = "Try convert this value into a `u64`."]
to_u64 -> u64,
#[doc = "Try convert this value into a `i64`."]
to_i64 -> i64,
#[doc = "Try convert this value into a `u128`."]
to_u128 -> u128,
#[doc = "Try convert this value into a `i128`."]
to_i128 -> i128,
#[doc = "Try convert this value into a `f64`."]
to_f64 -> f64,
#[doc = "Try convert this value into a `char`."]
to_char -> char,
#[doc = "Try convert this value into a `bool`."]
to_bool -> bool,
];
impl<'v> Value<'v> {
/// Try convert this value into an error.
#[cfg(feature = "kv_std")]
pub fn to_borrowed_error(&self) -> Option<&(dyn std::error::Error + 'static)> {
self.inner.to_borrowed_error()
}
/// Try convert this value into a borrowed string.
pub fn to_borrowed_str(&self) -> Option<&str> {
self.inner.to_borrowed_str()
}
}
#[cfg(feature = "kv_std")]
mod std_support {
use std::borrow::Cow;
use std::rc::Rc;
use std::sync::Arc;
use super::*;
impl<T> ToValue for Box<T>
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl<T> ToValue for Arc<T>
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl<T> ToValue for Rc<T>
where
T: ToValue + ?Sized,
{
fn to_value(&self) -> Value {
(**self).to_value()
}
}
impl ToValue for String {
fn to_value(&self) -> Value {
Value::from(&**self)
}
}
impl<'v> ToValue for Cow<'v, str> {
fn to_value(&self) -> Value {
Value::from(&**self)
}
}
impl<'v> Value<'v> {
/// Try convert this value into a string.
pub fn to_cow_str(&self) -> Option<Cow<'v, str>> {
self.inner.to_str()
}
}
impl<'v> From<&'v String> for Value<'v> {
fn from(v: &'v String) -> Self {
Value::from(&**v)
}
}
}
/// A visitor for a [`Value`].
///
/// Also see [`Value`'s documentation on seralization]. Value visitors are a simple alternative
/// to a more fully-featured serialization framework like `serde` or `sval`. A value visitor
/// can differentiate primitive types through methods like [`VisitValue::visit_bool`] and
/// [`VisitValue::visit_str`], but more complex types like maps and sequences
/// will fallthrough to [`VisitValue::visit_any`].
///
/// If you're trying to serialize a value to a format like JSON, you can use either `serde`
/// or `sval` directly with the value. You don't need a visitor.
///
/// [`Value`'s documentation on seralization]: Value#serialization
pub trait VisitValue<'v> {
/// Visit a `Value`.
///
/// This is the only required method on `VisitValue` and acts as a fallback for any
/// more specific methods that aren't overridden.
/// The `Value` may be formatted using its `fmt::Debug` or `fmt::Display` implementation,
/// or serialized using its `sval::Value` or `serde::Serialize` implementation.
fn visit_any(&mut self, value: Value) -> Result<(), Error>;
/// Visit an empty value.
fn visit_null(&mut self) -> Result<(), Error> {
self.visit_any(Value::null())
}
/// Visit an unsigned integer.
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a signed integer.
fn visit_i64(&mut self, value: i64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a big unsigned integer.
fn visit_u128(&mut self, value: u128) -> Result<(), Error> {
self.visit_any((value).into())
}
/// Visit a big signed integer.
fn visit_i128(&mut self, value: i128) -> Result<(), Error> {
self.visit_any((value).into())
}
/// Visit a floating point.
fn visit_f64(&mut self, value: f64) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a boolean.
fn visit_bool(&mut self, value: bool) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a string.
fn visit_str(&mut self, value: &str) -> Result<(), Error> {
self.visit_any(value.into())
}
/// Visit a string.
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
self.visit_str(value)
}
/// Visit a Unicode character.
fn visit_char(&mut self, value: char) -> Result<(), Error> {
let mut b = [0; 4];
self.visit_str(&*value.encode_utf8(&mut b))
}
/// Visit an error.
#[cfg(feature = "kv_std")]
fn visit_error(&mut self, err: &(dyn std::error::Error + 'static)) -> Result<(), Error> {
self.visit_any(Value::from_dyn_error(err))
}
/// Visit an error.
#[cfg(feature = "kv_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), Error> {
self.visit_any(Value::from_dyn_error(err))
}
}
impl<'a, 'v, T: ?Sized> VisitValue<'v> for &'a mut T
where
T: VisitValue<'v>,
{
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
(**self).visit_any(value)
}
fn visit_null(&mut self) -> Result<(), Error> {
(**self).visit_null()
}
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
(**self).visit_u64(value)
}
fn visit_i64(&mut self, value: i64) -> Result<(), Error> {
(**self).visit_i64(value)
}
fn visit_u128(&mut self, value: u128) -> Result<(), Error> {
(**self).visit_u128(value)
}
fn visit_i128(&mut self, value: i128) -> Result<(), Error> {
(**self).visit_i128(value)
}
fn visit_f64(&mut self, value: f64) -> Result<(), Error> {
(**self).visit_f64(value)
}
fn visit_bool(&mut self, value: bool) -> Result<(), Error> {
(**self).visit_bool(value)
}
fn visit_str(&mut self, value: &str) -> Result<(), Error> {
(**self).visit_str(value)
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
(**self).visit_borrowed_str(value)
}
fn visit_char(&mut self, value: char) -> Result<(), Error> {
(**self).visit_char(value)
}
#[cfg(feature = "kv_std")]
fn visit_error(&mut self, err: &(dyn std::error::Error + 'static)) -> Result<(), Error> {
(**self).visit_error(err)
}
#[cfg(feature = "kv_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), Error> {
(**self).visit_borrowed_error(err)
}
}
#[cfg(feature = "value-bag")]
pub(in crate::kv) mod inner {
/**
An implementation of `Value` based on a library called `value_bag`.
`value_bag` was written specifically for use in `log`'s value, but was split out when it outgrew
the codebase here. It's a general-purpose type-erasure library that handles mapping between
more fully-featured serialization frameworks.
*/
use super::*;
pub use value_bag::ValueBag as Inner;
pub use value_bag::Error;
#[cfg(test)]
pub use value_bag::test::TestToken as Token;
pub fn visit<'v>(
inner: &Inner<'v>,
visitor: impl VisitValue<'v>,
) -> Result<(), crate::kv::Error> {
struct InnerVisitValue<V>(V);
impl<'v, V> value_bag::visit::Visit<'v> for InnerVisitValue<V>
where
V: VisitValue<'v>,
{
fn visit_any(&mut self, value: value_bag::ValueBag) -> Result<(), Error> {
self.0
.visit_any(Value { inner: value })
.map_err(crate::kv::Error::into_value)
}
fn visit_empty(&mut self) -> Result<(), Error> {
self.0.visit_null().map_err(crate::kv::Error::into_value)
}
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
self.0
.visit_u64(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_i64(&mut self, value: i64) -> Result<(), Error> {
self.0
.visit_i64(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_u128(&mut self, value: u128) -> Result<(), Error> {
self.0
.visit_u128(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_i128(&mut self, value: i128) -> Result<(), Error> {
self.0
.visit_i128(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_f64(&mut self, value: f64) -> Result<(), Error> {
self.0
.visit_f64(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_bool(&mut self, value: bool) -> Result<(), Error> {
self.0
.visit_bool(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_str(&mut self, value: &str) -> Result<(), Error> {
self.0
.visit_str(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
self.0
.visit_borrowed_str(value)
.map_err(crate::kv::Error::into_value)
}
fn visit_char(&mut self, value: char) -> Result<(), Error> {
self.0
.visit_char(value)
.map_err(crate::kv::Error::into_value)
}
#[cfg(feature = "kv_std")]
fn visit_error(
&mut self,
err: &(dyn std::error::Error + 'static),
) -> Result<(), Error> {
self.0
.visit_error(err)
.map_err(crate::kv::Error::into_value)
}
#[cfg(feature = "kv_std")]
fn visit_borrowed_error(
&mut self,
err: &'v (dyn std::error::Error + 'static),
) -> Result<(), Error> {
self.0
.visit_borrowed_error(err)
.map_err(crate::kv::Error::into_value)
}
}
inner
.visit(&mut InnerVisitValue(visitor))
.map_err(crate::kv::Error::from_value)
}
}
#[cfg(not(feature = "value-bag"))]
pub(in crate::kv) mod inner {
/**
This is a dependency-free implementation of `Value` when there's no serialization frameworks involved.
In these simple cases a more fully featured solution like `value_bag` isn't needed, so we avoid pulling it in.
There are a few things here that need to remain consistent with the `value_bag`-based implementation:
1. Conversions should always produce the same results. If a conversion here returns `Some`, then
the same `value_bag`-based conversion must also. Of particular note here are floats to ints; they're
based on the standard library's `TryInto` conversions, which need to be convert to `i32` or `u32`,
and then to `f64`.
2. VisitValues should always be called in the same way. If a particular type of value calls `visit_i64`,
then the same `value_bag`-based visitor must also.
*/
use super::*;
#[derive(Clone)]
pub enum Inner<'v> {
None,
Bool(bool),
Str(&'v str),
Char(char),
I64(i64),
U64(u64),
F64(f64),
I128(i128),
U128(u128),
Debug(&'v dyn fmt::Debug),
Display(&'v dyn fmt::Display),
}
impl<'v> From<()> for Inner<'v> {
fn from(_: ()) -> Self {
Inner::None
}
}
impl<'v> From<bool> for Inner<'v> {
fn from(v: bool) -> Self {
Inner::Bool(v)
}
}
impl<'v> From<char> for Inner<'v> {
fn from(v: char) -> Self {
Inner::Char(v)
}
}
impl<'v> From<f32> for Inner<'v> {
fn from(v: f32) -> Self {
Inner::F64(v as f64)
}
}
impl<'v> From<f64> for Inner<'v> {
fn from(v: f64) -> Self {
Inner::F64(v)
}
}
impl<'v> From<i8> for Inner<'v> {
fn from(v: i8) -> Self {
Inner::I64(v as i64)
}
}
impl<'v> From<i16> for Inner<'v> {
fn from(v: i16) -> Self {
Inner::I64(v as i64)
}
}
impl<'v> From<i32> for Inner<'v> {
fn from(v: i32) -> Self {
Inner::I64(v as i64)
}
}
impl<'v> From<i64> for Inner<'v> {
fn from(v: i64) -> Self {
Inner::I64(v as i64)
}
}
impl<'v> From<isize> for Inner<'v> {
fn from(v: isize) -> Self {
Inner::I64(v as i64)
}
}
impl<'v> From<u8> for Inner<'v> {
fn from(v: u8) -> Self {
Inner::U64(v as u64)
}
}
impl<'v> From<u16> for Inner<'v> {
fn from(v: u16) -> Self {
Inner::U64(v as u64)
}
}
impl<'v> From<u32> for Inner<'v> {
fn from(v: u32) -> Self {
Inner::U64(v as u64)
}
}
impl<'v> From<u64> for Inner<'v> {
fn from(v: u64) -> Self {
Inner::U64(v as u64)
}
}
impl<'v> From<usize> for Inner<'v> {
fn from(v: usize) -> Self {
Inner::U64(v as u64)
}
}
impl<'v> From<i128> for Inner<'v> {
fn from(v: i128) -> Self {
Inner::I128(v)
}
}
impl<'v> From<u128> for Inner<'v> {
fn from(v: u128) -> Self {
Inner::U128(v)
}
}
impl<'v> From<&'v str> for Inner<'v> {
fn from(v: &'v str) -> Self {
Inner::Str(v)
}
}
impl<'v> fmt::Debug for Inner<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Inner::None => fmt::Debug::fmt(&None::<()>, f),
Inner::Bool(v) => fmt::Debug::fmt(v, f),
Inner::Str(v) => fmt::Debug::fmt(v, f),
Inner::Char(v) => fmt::Debug::fmt(v, f),
Inner::I64(v) => fmt::Debug::fmt(v, f),
Inner::U64(v) => fmt::Debug::fmt(v, f),
Inner::F64(v) => fmt::Debug::fmt(v, f),
Inner::I128(v) => fmt::Debug::fmt(v, f),
Inner::U128(v) => fmt::Debug::fmt(v, f),
Inner::Debug(v) => fmt::Debug::fmt(v, f),
Inner::Display(v) => fmt::Display::fmt(v, f),
}
}
}
impl<'v> fmt::Display for Inner<'v> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
Inner::None => fmt::Debug::fmt(&None::<()>, f),
Inner::Bool(v) => fmt::Display::fmt(v, f),
Inner::Str(v) => fmt::Display::fmt(v, f),
Inner::Char(v) => fmt::Display::fmt(v, f),
Inner::I64(v) => fmt::Display::fmt(v, f),
Inner::U64(v) => fmt::Display::fmt(v, f),
Inner::F64(v) => fmt::Display::fmt(v, f),
Inner::I128(v) => fmt::Display::fmt(v, f),
Inner::U128(v) => fmt::Display::fmt(v, f),
Inner::Debug(v) => fmt::Debug::fmt(v, f),
Inner::Display(v) => fmt::Display::fmt(v, f),
}
}
}
impl<'v> Inner<'v> {
pub fn from_debug<T: fmt::Debug>(value: &'v T) -> Self {
Inner::Debug(value)
}
pub fn from_display<T: fmt::Display>(value: &'v T) -> Self {
Inner::Display(value)
}
pub fn from_dyn_debug(value: &'v dyn fmt::Debug) -> Self {
Inner::Debug(value)
}
pub fn from_dyn_display(value: &'v dyn fmt::Display) -> Self {
Inner::Display(value)
}
pub fn empty() -> Self {
Inner::None
}
pub fn to_bool(&self) -> Option<bool> {
match self {
Inner::Bool(v) => Some(*v),
_ => None,
}
}
pub fn to_char(&self) -> Option<char> {
match self {
Inner::Char(v) => Some(*v),
_ => None,
}
}
pub fn to_f64(&self) -> Option<f64> {
match self {
Inner::F64(v) => Some(*v),
Inner::I64(v) => {
let v: i32 = (*v).try_into().ok()?;
v.try_into().ok()
}
Inner::U64(v) => {
let v: u32 = (*v).try_into().ok()?;
v.try_into().ok()
}
Inner::I128(v) => {
let v: i32 = (*v).try_into().ok()?;
v.try_into().ok()
}
Inner::U128(v) => {
let v: u32 = (*v).try_into().ok()?;
v.try_into().ok()
}
_ => None,
}
}
pub fn to_i64(&self) -> Option<i64> {
match self {
Inner::I64(v) => Some(*v),
Inner::U64(v) => (*v).try_into().ok(),
Inner::I128(v) => (*v).try_into().ok(),
Inner::U128(v) => (*v).try_into().ok(),
_ => None,
}
}
pub fn to_u64(&self) -> Option<u64> {
match self {
Inner::U64(v) => Some(*v),
Inner::I64(v) => (*v).try_into().ok(),
Inner::I128(v) => (*v).try_into().ok(),
Inner::U128(v) => (*v).try_into().ok(),
_ => None,
}
}
pub fn to_u128(&self) -> Option<u128> {
match self {
Inner::U128(v) => Some(*v),
Inner::I64(v) => (*v).try_into().ok(),
Inner::U64(v) => (*v).try_into().ok(),
Inner::I128(v) => (*v).try_into().ok(),
_ => None,
}
}
pub fn to_i128(&self) -> Option<i128> {
match self {
Inner::I128(v) => Some(*v),
Inner::I64(v) => (*v).try_into().ok(),
Inner::U64(v) => (*v).try_into().ok(),
Inner::U128(v) => (*v).try_into().ok(),
_ => None,
}
}
pub fn to_borrowed_str(&self) -> Option<&'v str> {
match self {
Inner::Str(v) => Some(v),
_ => None,
}
}
#[cfg(test)]
pub fn to_test_token(&self) -> Token {
match self {
Inner::None => Token::None,
Inner::Bool(v) => Token::Bool(*v),
Inner::Str(v) => Token::Str(*v),
Inner::Char(v) => Token::Char(*v),
Inner::I64(v) => Token::I64(*v),
Inner::U64(v) => Token::U64(*v),
Inner::F64(v) => Token::F64(*v),
Inner::I128(_) => unimplemented!(),
Inner::U128(_) => unimplemented!(),
Inner::Debug(_) => unimplemented!(),
Inner::Display(_) => unimplemented!(),
}
}
}
#[cfg(test)]
#[derive(Debug, PartialEq)]
pub enum Token<'v> {
None,
Bool(bool),
Char(char),
Str(&'v str),
F64(f64),
I64(i64),
U64(u64),
}
pub fn visit<'v>(
inner: &Inner<'v>,
mut visitor: impl VisitValue<'v>,
) -> Result<(), crate::kv::Error> {
match inner {
Inner::None => visitor.visit_null(),
Inner::Bool(v) => visitor.visit_bool(*v),
Inner::Str(v) => visitor.visit_borrowed_str(*v),
Inner::Char(v) => visitor.visit_char(*v),
Inner::I64(v) => visitor.visit_i64(*v),
Inner::U64(v) => visitor.visit_u64(*v),
Inner::F64(v) => visitor.visit_f64(*v),
Inner::I128(v) => visitor.visit_i128(*v),
Inner::U128(v) => visitor.visit_u128(*v),
Inner::Debug(v) => visitor.visit_any(Value::from_dyn_debug(*v)),
Inner::Display(v) => visitor.visit_any(Value::from_dyn_display(*v)),
}
}
}
impl<'v> Value<'v> {
/// Get a value from a type implementing `std::fmt::Debug`.
#[cfg(feature = "kv_unstable")]
#[deprecated(note = "use `from_debug` instead")]
pub fn capture_debug<T>(value: &'v T) -> Self
where
T: fmt::Debug + 'static,
{
Value::from_debug(value)
}
/// Get a value from a type implementing `std::fmt::Display`.
#[cfg(feature = "kv_unstable")]
#[deprecated(note = "use `from_display` instead")]
pub fn capture_display<T>(value: &'v T) -> Self
where
T: fmt::Display + 'static,
{
Value::from_display(value)
}
/// Get a value from an error.
#[cfg(feature = "kv_unstable_std")]
#[deprecated(note = "use `from_dyn_error` instead")]
pub fn capture_error<T>(err: &'v T) -> Self
where
T: std::error::Error + 'static,
{
Value::from_dyn_error(err)
}
/// Get a value from a type implementing `serde::Serialize`.
#[cfg(feature = "kv_unstable_serde")]
#[deprecated(note = "use `from_serde` instead")]
pub fn capture_serde<T>(value: &'v T) -> Self
where
T: serde::Serialize + 'static,
{
Value::from_serde(value)
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_unstable_sval")]
#[deprecated(note = "use `from_sval` instead")]
pub fn capture_sval<T>(value: &'v T) -> Self
where
T: sval::Value + 'static,
{
Value::from_sval(value)
}
/// Check whether this value can be downcast to `T`.
#[cfg(feature = "kv_unstable")]
#[deprecated(
note = "downcasting has been removed; log an issue at https://github.com/rust-lang/log/issues if this is something you rely on"
)]
pub fn is<T: 'static>(&self) -> bool {
false
}
/// Try downcast this value to `T`.
#[cfg(feature = "kv_unstable")]
#[deprecated(
note = "downcasting has been removed; log an issue at https://github.com/rust-lang/log/issues if this is something you rely on"
)]
pub fn downcast_ref<T: 'static>(&self) -> Option<&T> {
None
}
}
// NOTE: Deprecated; but aliases can't carry this attribute
#[cfg(feature = "kv_unstable")]
pub use VisitValue as Visit;
/// Get a value from a type implementing `std::fmt::Debug`.
#[cfg(feature = "kv_unstable")]
#[deprecated(note = "use the `key:? = value` macro syntax instead")]
#[macro_export]
macro_rules! as_debug {
($capture:expr) => {
$crate::kv::Value::from_debug(&$capture)
};
}
/// Get a value from a type implementing `std::fmt::Display`.
#[cfg(feature = "kv_unstable")]
#[deprecated(note = "use the `key:% = value` macro syntax instead")]
#[macro_export]
macro_rules! as_display {
($capture:expr) => {
$crate::kv::Value::from_display(&$capture)
};
}
/// Get a value from an error.
#[cfg(feature = "kv_unstable_std")]
#[deprecated(note = "use the `key:err = value` macro syntax instead")]
#[macro_export]
macro_rules! as_error {
($capture:expr) => {
$crate::kv::Value::from_dyn_error(&$capture)
};
}
#[cfg(feature = "kv_unstable_serde")]
#[deprecated(note = "use the `key:serde = value` macro syntax instead")]
/// Get a value from a type implementing `serde::Serialize`.
#[macro_export]
macro_rules! as_serde {
($capture:expr) => {
$crate::kv::Value::from_serde(&$capture)
};
}
/// Get a value from a type implementing `sval::Value`.
#[cfg(feature = "kv_unstable_sval")]
#[deprecated(note = "use the `key:sval = value` macro syntax instead")]
#[macro_export]
macro_rules! as_sval {
($capture:expr) => {
$crate::kv::Value::from_sval(&$capture)
};
}
#[cfg(test)]
pub(crate) mod tests {
use super::*;
impl<'v> Value<'v> {
pub(crate) fn to_token(&self) -> inner::Token {
self.inner.to_test_token()
}
}
fn unsigned() -> impl Iterator<Item = Value<'static>> {
vec![
Value::from(8u8),
Value::from(16u16),
Value::from(32u32),
Value::from(64u64),
Value::from(1usize),
Value::from(std::num::NonZeroU8::new(8).unwrap()),
Value::from(std::num::NonZeroU16::new(16).unwrap()),
Value::from(std::num::NonZeroU32::new(32).unwrap()),
Value::from(std::num::NonZeroU64::new(64).unwrap()),
Value::from(std::num::NonZeroUsize::new(1).unwrap()),
]
.into_iter()
}
fn signed() -> impl Iterator<Item = Value<'static>> {
vec![
Value::from(-8i8),
Value::from(-16i16),
Value::from(-32i32),
Value::from(-64i64),
Value::from(-1isize),
Value::from(std::num::NonZeroI8::new(-8).unwrap()),
Value::from(std::num::NonZeroI16::new(-16).unwrap()),
Value::from(std::num::NonZeroI32::new(-32).unwrap()),
Value::from(std::num::NonZeroI64::new(-64).unwrap()),
Value::from(std::num::NonZeroIsize::new(-1).unwrap()),
]
.into_iter()
}
fn float() -> impl Iterator<Item = Value<'static>> {
vec![Value::from(32.32f32), Value::from(64.64f64)].into_iter()
}
fn bool() -> impl Iterator<Item = Value<'static>> {
vec![Value::from(true), Value::from(false)].into_iter()
}
fn str() -> impl Iterator<Item = Value<'static>> {
vec![Value::from("a string"), Value::from("a loong string")].into_iter()
}
fn char() -> impl Iterator<Item = Value<'static>> {
vec![Value::from('a'), Value::from('⛰')].into_iter()
}
#[test]
fn test_to_value_display() {
assert_eq!(42u64.to_value().to_string(), "42");
assert_eq!(42i64.to_value().to_string(), "42");
assert_eq!(42.01f64.to_value().to_string(), "42.01");
assert_eq!(true.to_value().to_string(), "true");
assert_eq!('a'.to_value().to_string(), "a");
assert_eq!("a loong string".to_value().to_string(), "a loong string");
assert_eq!(Some(true).to_value().to_string(), "true");
assert_eq!(().to_value().to_string(), "None");
assert_eq!(None::<bool>.to_value().to_string(), "None");
}
#[test]
fn test_to_value_structured() {
assert_eq!(42u64.to_value().to_token(), inner::Token::U64(42));
assert_eq!(42i64.to_value().to_token(), inner::Token::I64(42));
assert_eq!(42.01f64.to_value().to_token(), inner::Token::F64(42.01));
assert_eq!(true.to_value().to_token(), inner::Token::Bool(true));
assert_eq!('a'.to_value().to_token(), inner::Token::Char('a'));
assert_eq!(
"a loong string".to_value().to_token(),
inner::Token::Str("a loong string".into())
);
assert_eq!(Some(true).to_value().to_token(), inner::Token::Bool(true));
assert_eq!(().to_value().to_token(), inner::Token::None);
assert_eq!(None::<bool>.to_value().to_token(), inner::Token::None);
}
#[test]
fn test_to_number() {
for v in unsigned() {
assert!(v.to_u64().is_some());
assert!(v.to_i64().is_some());
}
for v in signed() {
assert!(v.to_i64().is_some());
}
for v in unsigned().chain(signed()).chain(float()) {
assert!(v.to_f64().is_some());
}
for v in bool().chain(str()).chain(char()) {
assert!(v.to_u64().is_none());
assert!(v.to_i64().is_none());
assert!(v.to_f64().is_none());
}
}
#[test]
fn test_to_float() {
// Only integers from i32::MIN..=u32::MAX can be converted into floats
assert!(Value::from(i32::MIN).to_f64().is_some());
assert!(Value::from(u32::MAX).to_f64().is_some());
assert!(Value::from((i32::MIN as i64) - 1).to_f64().is_none());
assert!(Value::from((u32::MAX as u64) + 1).to_f64().is_none());
}
#[test]
fn test_to_cow_str() {
for v in str() {
assert!(v.to_borrowed_str().is_some());
#[cfg(feature = "kv_std")]
assert!(v.to_cow_str().is_some());
}
let short_lived = String::from("short lived");
let v = Value::from(&*short_lived);
assert!(v.to_borrowed_str().is_some());
#[cfg(feature = "kv_std")]
assert!(v.to_cow_str().is_some());
for v in unsigned().chain(signed()).chain(float()).chain(bool()) {
assert!(v.to_borrowed_str().is_none());
#[cfg(feature = "kv_std")]
assert!(v.to_cow_str().is_none());
}
}
#[test]
fn test_to_bool() {
for v in bool() {
assert!(v.to_bool().is_some());
}
for v in unsigned()
.chain(signed())
.chain(float())
.chain(str())
.chain(char())
{
assert!(v.to_bool().is_none());
}
}
#[test]
fn test_to_char() {
for v in char() {
assert!(v.to_char().is_some());
}
for v in unsigned()
.chain(signed())
.chain(float())
.chain(str())
.chain(bool())
{
assert!(v.to_char().is_none());
}
}
#[test]
fn test_visit_integer() {
struct Extract(Option<u64>);
impl<'v> VisitValue<'v> for Extract {
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
unimplemented!("unexpected value: {value:?}")
}
fn visit_u64(&mut self, value: u64) -> Result<(), Error> {
self.0 = Some(value);
Ok(())
}
}
let mut extract = Extract(None);
Value::from(42u64).visit(&mut extract).unwrap();
assert_eq!(Some(42), extract.0);
}
#[test]
fn test_visit_borrowed_str() {
struct Extract<'v>(Option<&'v str>);
impl<'v> VisitValue<'v> for Extract<'v> {
fn visit_any(&mut self, value: Value) -> Result<(), Error> {
unimplemented!("unexpected value: {value:?}")
}
fn visit_borrowed_str(&mut self, value: &'v str) -> Result<(), Error> {
self.0 = Some(value);
Ok(())
}
}
let mut extract = Extract(None);
let short_lived = String::from("A short-lived string");
Value::from(&*short_lived).visit(&mut extract).unwrap();
assert_eq!(Some("A short-lived string"), extract.0);
}
}
Codebase Browser
chromium