haxeformat/serde/

adapter.rs

use std::fmt;
use std::marker::PhantomData;
use std::ops::{Deref, DerefMut};

use serde::{de, Deserialize, Deserializer, Serialize, Serializer};

impl Serialize for crate::raw::HaxeDate {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        serializer.serialize_i64(chrono::NaiveDateTime::from(*self).timestamp())
    }
}

impl<'de> Deserialize<'de> for crate::raw::HaxeDate {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        let timestamp: i64 = Deserialize::deserialize(deserializer)?;
        crate::raw::HaxeDate::try_from_timestamp(timestamp).ok_or_else(|| {
            de::Error::invalid_value(de::Unexpected::Signed(timestamp), &"valid timestamp")
        })
    }
}

macro_rules! declare_markers {
    ($vis:vis enum $marker_enum:ident($marker_prefix:expr) {
        $(
            $(#[$adapter_meta:meta])*
            $marker_name:ident($adapter_vis:vis $adapter_name:ident($module:ident))
        ),* $(,)?
    }) => {
        #[derive(Debug, Copy, Clone, Eq, PartialEq)]
        $vis enum $marker_enum {
            $($marker_name,)*
            Unknown
        }

        impl $marker_enum {
            $vis fn parse(string: &str) -> Option<Self> {
                if !string.starts_with($marker_prefix) {
                    return None;
                }
                match &string[$marker_prefix.len()..] {
                    $(stringify!($marker_name) => Some(Self::$marker_name),)*
                    _ => Some(Self::Unknown)
                }
            }

            #[allow(clippy::wrong_self_convention)]
            $vis fn to_str(&self) -> &'static str {
                match *self {
                    $(Self::$marker_name => concat!($marker_prefix, stringify!($marker_name)),)*
                    Self::Unknown => concat!($marker_prefix, "unknown")
                }
            }
        }

        $(declare_markers!(
            @declare_adapter $(#[$adapter_meta])*
            $adapter_vis struct $adapter_name($module) => $marker_enum::$marker_name
        );)*

    };
    (@declare_adapter $(#[$meta:meta])* $vis:vis struct $adapter:ident($module:ident) => $marker:path) => {

        $(#[$meta])*
        $vis mod $module {
            #![allow(dead_code)]
            use super::$adapter;
            use serde::{ Serialize, Serializer, Deserialize, Deserializer };

            pub fn serialize<T: Serialize, S: Serializer>(value: &T, ser: S) -> Result<S::Ok, S::Error> {
                $adapter(value).serialize(ser)
            }

            pub fn deserialize<'de, T: Deserialize<'de>, D: Deserializer<'de>>(de: D) -> Result<T, D::Error> {
                let val: $adapter<T> = Deserialize::deserialize(de)?;
                Ok(val.0)
            }
        }

        $(#[$meta])*
        #[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
        #[repr(transparent)]
        $vis struct $adapter<T>($vis T);

        impl<T: fmt::Display> fmt::Display for $adapter<T> {
            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
                self.0.fmt(f)
            }
        }

        impl<T> From<T> for $adapter<T> {
            fn from(inner: T) -> Self { Self(inner) }
        }

        impl<T> Deref for $adapter<T> {
            type Target = T;
            fn deref(&self) -> &T { &self.0 }
        }

        impl<T> DerefMut for $adapter<T> {
            fn deref_mut(&mut self) -> &mut T { &mut self.0 }
        }

        impl<T: Serialize> Serialize for $adapter<T> {
            fn serialize<S: Serializer>(&self, ser: S) -> Result<S::Ok, S::Error> {
                ser.serialize_newtype_struct($marker.to_str(), &self.0)
            }
        }

        impl<'de, T: Deserialize<'de>> Deserialize<'de> for $adapter<T> {
            fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
                let vis = AdapterVisitor {
                    kind: $marker,
                    _marker: PhantomData::<T>,
                    _lifetime: PhantomData::<&'de ()>,
                };
                deserializer.deserialize_newtype_struct($marker.to_str(), vis)
                    .map($adapter)
            }
        }
    }
}

struct AdapterVisitor<'de, T> {
    kind: AdapterMarker,
    _marker: PhantomData<T>,
    _lifetime: PhantomData<&'de ()>,
}

impl<'de, T: Deserialize<'de>> de::Visitor<'de> for AdapterVisitor<'de, T> {
    type Value = T;
    fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "adapter struct {:?}", self.kind)
    }

    fn visit_seq<A: de::SeqAccess<'de>>(self, mut seq: A) -> Result<T, A::Error> {
        match seq.next_element()? {
            None => Err(<A::Error as de::Error>::invalid_length(0, &self)),
            Some(value) => Ok(value),
        }
    }

    fn visit_newtype_struct<D: Deserializer<'de>>(self, de: D) -> Result<T, D::Error> {
        T::deserialize(de)
    }
}

declare_markers! { pub(super) enum AdapterMarker("\0haxeformat::") {
    /// Forces Haxe `Date` representation.
    /// Accepts integers (as timestamps).
    Date(pub DateAdapter(date)),
    /// Forces Haxe `Array` representation (the default for sequences).
    /// Accepts sequences, tuples and tuple structs.
    Array(pub ArrayAdapter(array)),
    /// Forces Haxe `List` representation.
    /// Accepts sequences, tuples and tuple structs.
    List(pub ListAdapter(list)),
    /// Forces Haxe `struct` representation (the default for maps).
    /// Accepts only structs and maps, with string keys.
    Struct(pub StructAdapter(struct_obj)),
    /// Forces Haxe `StringMap` representation.
    /// Accepts only maps, with string keys.
    StringMap(pub StringMapAdapter(string)),
    /// Forces Haxe `IntMap` representation.
    /// Accepts only maps, with integer keys.
    IntMap(pub IntMapAdapter(int)),
    /// Forces Haxe `ObjectMap` representation.
    /// Accepts only maps, with arbitrary keys.
    ObjectMap(pub ObjectMapAdapter(object)),
    /// Forces Haxe `class` representation.
    /// Accepts only structs.
    Class(pub ClassAdapter(class)),
    /// Forces Haxe `Class<T>` representation.
    /// Accepts only strings.
    ClassDef(pub ClassDefAdapter(class_def)),
    /// Forces Haxe `Enum<T>` representation.
    /// Accepts only strings.
    EnumDef(pub EnumDefAdapter(enum_def)),
    // TODO: add serde support for CustomAdapter
    Custom(CustomAdapter(custom)),
    /// Forces Haxe `exception` representation (throws on deserialization).
    /// Accepts any value.
    Exception(pub ExceptionAdapter(exception)),
}}