buni-rs 1.0.0

use crate::error::{Result};
use serde::{Serialize, ser};

mod error;
mod util;

pub use error::SerializeError;
use crate::serialize::util::escape_buni;

pub struct Serializer {
    output: String,
}

pub fn to_string<T>(value: &T) -> Result<String, SerializeError>
where
    T: Serialize,
{
    let mut serializer = Serializer {
        output: String::new(),
    };
    value.serialize(&mut serializer)?;
    Ok(serializer.output)
}

impl<'a> ser::Serializer for &'a mut Serializer {
    type Ok = ();
    type Error = SerializeError;
    type SerializeSeq = SequenceSerializer<'a>;
    type SerializeTuple = SequenceSerializer<'a>;
    type SerializeTupleStruct = SequenceSerializer<'a>;
    type SerializeTupleVariant = Self;
    type SerializeMap = SequenceSerializer<'a>;
    type SerializeStruct = SequenceSerializer<'a>;
    type SerializeStructVariant = Self;

    fn serialize_bool(self, v: bool) -> Result<(), SerializeError> {
        self.output += if v { "true" } else { "false" };
        Ok(())
    }

    fn serialize_i8(self, v: i8) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }
    fn serialize_i16(self, v: i16) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_i32(self, v: i32) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_i64(self, v: i64) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_u8(self, v: u8) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_u16(self, v: u16) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_u32(self, v: u32) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_u64(self, v: u64) -> Result<(), SerializeError> {
        self.output.push_str(itoa::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_f32(self, v: f32) -> Result<(), SerializeError> {
        self.output.push_str(ryu::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_f64(self, v: f64) -> Result<(), SerializeError> {
        self.output.push_str(ryu::Buffer::new().format(v));
        Ok(())
    }

    fn serialize_char(self, v: char) -> Result<(), SerializeError> {
        self.serialize_str(&v.to_string())
    }

    fn serialize_str(self, v: &str) -> Result<(), SerializeError> {
        self.output.push_str(&escape_buni(v));
        Ok(())
    }

    fn serialize_bytes(self, v: &[u8]) -> Result<(), SerializeError> {
        use serde::ser::SerializeSeq;
        let mut seq = self.serialize_seq(Some(v.len()))?;
        for byte in v {
            seq.serialize_element(byte)?;
        }
        seq.end()
    }

    fn serialize_none(self) -> Result<(), SerializeError> {
        self.serialize_unit()
    }

    fn serialize_some<T>(self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        self.output += "(";
        value.serialize(&mut *self)?;
        self.output += ")";
        Ok(())
    }

    fn serialize_unit(self) -> Result<(), SerializeError> {
        self.output.push_str("null");
        Ok(())
    }

    fn serialize_unit_struct(self, _name: &'static str) -> Result<(), SerializeError> {
        self.serialize_unit()
    }

    fn serialize_unit_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
    ) -> Result<(), SerializeError> {
        self.serialize_str(variant)
    }

    fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        value.serialize(self)
    }

    fn serialize_newtype_variant<T>(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        value: &T,
    ) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        variant.serialize(&mut *self)?;
        self.output.push_str("(");
        value.serialize(&mut *self)?;
        self.output.push_str(")");
        Ok(())
    }

    fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq, SerializeError> {
        if self.output.ends_with("(") {
            Ok(SequenceSerializer {
                terminate: false,
                serializer: self,
            })
        } else {
            self.output += "(";
            Ok(SequenceSerializer {
                terminate: true,
                serializer: self,
            })
        }
    }

    fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, SerializeError> {
        self.serialize_seq(Some(len))
    }

    fn serialize_tuple_struct(
        self,
        _name: &'static str,
        len: usize,
    ) -> Result<Self::SerializeTupleStruct, SerializeError> {
        self.serialize_seq(Some(len))
    }

    fn serialize_tuple_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        _len: usize,
    ) -> Result<Self::SerializeTupleVariant, SerializeError> {
        variant.serialize(&mut *self)?;
        self.output += "(";
        Ok(self)
    }

    fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, SerializeError> {
        self.serialize_seq(len)
    }

    fn serialize_struct(self, _name: &'static str, len: usize) -> Result<Self::SerializeStruct, SerializeError> {
        self.serialize_seq(Some(len))
    }

    fn serialize_struct_variant(
        self,
        _name: &'static str,
        _variant_index: u32,
        variant: &'static str,
        _len: usize,
    ) -> Result<Self::SerializeStructVariant, SerializeError> {
        variant.serialize(&mut *self)?;
        self.output += "(";
        Ok(self)
    }
}

pub struct SequenceSerializer<'a> {
    serializer: &'a mut Serializer,
    terminate: bool,
}

impl<'a> ser::SerializeSeq for SequenceSerializer<'a> {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_element<T>(&mut self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.serializer.output.ends_with('(') {
            self.serializer.output += ",";
        }
        value.serialize(&mut *self.serializer)
    }

    fn end(self) -> Result<(), SerializeError> {
        if self.terminate {
            self.serializer.output += ")";
        }
        Ok(())
    }
}

impl<'a> ser::SerializeTuple for SequenceSerializer<'a> {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_element<T>(&mut self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.serializer.output.ends_with('(') {
            self.serializer.output += ",";
        }
        value.serialize(&mut *self.serializer)
    }

    fn end(self) -> Result<(), SerializeError> {
        if self.terminate {
            self.serializer.output += ")";
        }
        Ok(())
    }
}

impl<'a> ser::SerializeTupleStruct for SequenceSerializer<'a> {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_field<T>(&mut self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.serializer.output.ends_with('(') {
            self.serializer.output += ",";
        }
        value.serialize(&mut *self.serializer)
    }

    fn end(self) -> Result<(), SerializeError> {
        if self.terminate {
            self.serializer.output += ")";
        }
        Ok(())
    }
}

impl<'a> ser::SerializeTupleVariant for &mut Serializer {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_field<T>(&mut self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.output.ends_with('(') {
            self.output += ",";
        }
        value.serialize(&mut **self)
    }

    fn end(self) -> Result<(), SerializeError> {
        self.output += ")";
        Ok(())
    }
}

impl<'a> ser::SerializeMap for SequenceSerializer<'a> {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_key<T>(&mut self, key: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.serializer.output.ends_with('(') {
            self.serializer.output += ",";
        }
        key.serialize(&mut *self.serializer)
    }

    fn serialize_value<T>(&mut self, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        self.serializer.output += "(";
        value.serialize(&mut *self.serializer)?;
        self.serializer.output += ")";
        Ok(())
    }

    fn end(self) -> Result<(), SerializeError> {
        if self.terminate {
            self.serializer.output += ")";
        }
        Ok(())
    }
}

impl<'a> ser::SerializeStruct for SequenceSerializer<'a> {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.serializer.output.ends_with('(') {
            self.serializer.output += ",";
        }
        key.serialize(&mut *self.serializer)?;
        self.serializer.output += "(";
        value.serialize(&mut *self.serializer)?;
        self.serializer.output += ")";
        Ok(())
    }

    fn end(self) -> Result<(), SerializeError> {
        if self.terminate {
            self.serializer.output += ")";
        }
        Ok(())
    }
}

impl<'a> ser::SerializeStructVariant for &mut Serializer {
    type Ok = ();
    type Error = SerializeError;

    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<(), SerializeError>
    where
        T: ?Sized + Serialize,
    {
        if !self.output.ends_with('(') {
            self.output += ",";
        }
        key.serialize(&mut **self)?;
        self.output += "(";
        value.serialize(&mut **self)?;
        self.output += ")";
        Ok(())
    }

    fn end(self) -> Result<(), SerializeError> {
        self.output += ")";
        Ok(())
    }
}

#[test]
fn test_map() {
    // Using HashMap here messes up sorting order. Don't use.
    use std::collections::BTreeMap;
    let mut map = BTreeMap::new();
    map.insert("a", 1);
    map.insert("b", 2);

    let expected = r#"(a(1),b(2))"#;
    assert_eq!(to_string(&map).unwrap(), expected);
}

#[test]
fn test_struct() {
    #[derive(Serialize)]
    struct Test {
        int: u32,
        seq: Vec<&'static str>,
    }

    let test = Test {
        int: 1,
        seq: vec!["a", "b"],
    };
    let expected = r#"(int(1),seq(a,b))"#;
    assert_eq!(to_string(&test).unwrap(), expected);
}

#[test]
fn test_enum() {
    #[derive(Serialize)]
    enum E {
        Unit,
        Newtype(u32),
        Tuple(u32, u32),
        Struct { a: u32 },
    }

    let u = E::Unit;
    let expected = r#"Unit"#;
    assert_eq!(to_string(&u).unwrap(), expected);

    let n = E::Newtype(1);
    let expected = r#"Newtype(1)"#;
    assert_eq!(to_string(&n).unwrap(), expected);

    let t = E::Tuple(1, 2);
    let expected = r#"Tuple(1,2)"#;
    assert_eq!(to_string(&t).unwrap(), expected);

    let s = E::Struct { a: 1 };
    let expected = r#"Struct(a(1))"#;
    assert_eq!(to_string(&s).unwrap(), expected);
}