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use serde::{Serialize, Serializer, Deserialize, Deserializer};
use serde::de::Visitor;
use std::fmt;
macro_rules! signed_fixed_point_impl {
($name:ident, $epsilon_type:ty, $int_bits:expr, $frac_bits:expr) => {
#[derive(PartialEq, Eq)]
pub struct $name {
epsilon: $epsilon_type,
}
impl $name {
pub fn from_epsilons(epsilon: $epsilon_type) -> $name {
$name {epsilon: epsilon}
}
}
impl fmt::Debug for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"{}0x{:0int_width$x}.{:0frac_width$x}",
if self.epsilon < 0 {"-"} else {"+"},
self.epsilon >> $frac_bits,
self.epsilon & ((1 << $frac_bits) - 1),
int_width = $int_bits / 4,
frac_width = $frac_bits / 4,
)
}
}
impl Serialize for $name {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
serializer.serialize_str(&format!("{:?}", self))
}
}
impl<'a> Deserialize<'a> for $name {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'a> {
use serde::de;
use regex::Regex;
struct FixedPointVisitor;
impl<'b> Visitor<'b> for FixedPointVisitor {
type Value = $name;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a string following the pattern ^[+-]0x[0-9a-f]+\\.[0-9a-f]+$")
}
fn visit_str<E>(self, value: &str) -> Result<$name, E> where E: de::Error {
lazy_static! {
static ref FIXED_POINT_RE: Regex = Regex::new("^([+-])0x([0-9a-f]{2,4})\\.([0-9a-f]{2,4})$").unwrap();
}
match FIXED_POINT_RE.captures(value) {
Some(caps) => {
let sign: $epsilon_type = if &caps[1] == "-" {-1} else {1};
let int_part: $epsilon_type = i64::from_str_radix(&caps[2], 16).unwrap() as $epsilon_type;
let frac_part: $epsilon_type = i64::from_str_radix(&caps[3], 16).unwrap() as $epsilon_type;
Ok($name::from_epsilons((sign * int_part << $frac_bits) + sign * frac_part))
},
None => Err(E::custom(format!("Invalid fixed point: {}", value))),
}
}
}
deserializer.deserialize_str(FixedPointVisitor)
}
}
}
}
macro_rules! unsigned_fixed_point_impl {
($name:ident, $epsilon_type:ty, $int_bits:expr, $frac_bits:expr) => {
#[derive(PartialEq, Eq)]
pub struct $name {
epsilon: $epsilon_type,
}
impl $name {
pub fn from_epsilons(epsilon: $epsilon_type) -> $name {
$name {epsilon: epsilon}
}
}
impl fmt::Debug for $name {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(
f,
"+0x{:0int_width$x}.{:0frac_width$x}",
self.epsilon >> $frac_bits,
self.epsilon & ((1 << $frac_bits) - 1),
int_width = $int_bits / 4,
frac_width = $frac_bits / 4,
)
}
}
impl Serialize for $name {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
serializer.serialize_str(&format!("{:?}", self))
}
}
impl<'a> Deserialize<'a> for $name {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where D: Deserializer<'a> {
use serde::de;
use regex::Regex;
struct FixedPointVisitor;
impl<'b> Visitor<'b> for FixedPointVisitor {
type Value = $name;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a string following the pattern ^[+-]0x[0-9a-f]+\\.[0-9a-f]+$")
}
fn visit_str<E>(self, value: &str) -> Result<$name, E> where E: de::Error {
lazy_static! {
static ref FIXED_POINT_RE: Regex = Regex::new("^+0x([0-9a-f]{2,4})\\.([0-9a-f]{2,4})$").unwrap();
}
match FIXED_POINT_RE.captures(value) {
Some(caps) => {
let int_part: $epsilon_type = u64::from_str_radix(&caps[1], 16).unwrap() as $epsilon_type;
let frac_part: $epsilon_type = u64::from_str_radix(&caps[2], 16).unwrap() as $epsilon_type;
Ok($name::from_epsilons((int_part << $frac_bits) + frac_part))
},
None => Err(E::custom(format!("Invalid fixed point: {}", value))),
}
}
}
deserializer.deserialize_str(FixedPointVisitor)
}
}
}
}
signed_fixed_point_impl!(Fixed8P8, i16, 8, 8);
signed_fixed_point_impl!(Fixed16P16, i32, 16, 16);
unsigned_fixed_point_impl!(Ufixed8P8, u16, 8, 8);
unsigned_fixed_point_impl!(Ufixed16P16, u32, 16, 16);
#[cfg(test)]
mod tests {
use super::Fixed16P16;
use serde_json;
use std::fmt::Write;
#[test]
fn test_eq() {
assert_eq!(Fixed16P16::from_epsilons(3), Fixed16P16::from_epsilons(3));
}
#[test]
fn test_json_serde_serialization() {
assert_eq!(serde_json::to_string(&Fixed16P16::from_epsilons(3)).unwrap(), "\"+0x0000.0003\"");
}
#[test]
fn test_json_serde_deserialization() {
assert_eq!(serde_json::from_str::<Fixed16P16>("\"+0x0000.0000\"").unwrap(), Fixed16P16::from_epsilons(0));
assert_eq!(serde_json::from_str::<Fixed16P16>("\"+0x0000.0003\"").unwrap(), Fixed16P16::from_epsilons(3));
assert_eq!(serde_json::from_str::<Fixed16P16>("\"+0x0001.0000\"").unwrap(), Fixed16P16::from_epsilons(65536));
assert_eq!(serde_json::from_str::<Fixed16P16>("\"+0x7fff.ffff\"").unwrap(), Fixed16P16::from_epsilons(2147483647));
assert_eq!(serde_json::from_str::<Fixed16P16>("\"-0x8000.0000\"").unwrap(), Fixed16P16::from_epsilons(-2147483648));
}
}