1 // Copyright 2020-2021 Ian Jackson and contributors to Otter
2 // SPDX-License-Identifier: AGPL-3.0-or-later
3 // There is NO WARRANTY.
6 use otter_base::crates::*;
8 use std::fmt::{Debug, Display};
9 use std::iter::Peekable;
13 use if_chain::if_chain;
16 use serde::forward_to_deserialize_any;
18 Deserialize, DeserializeOwned, Deserializer,
19 DeserializeSeed, EnumAccess,
20 IntoDeserializer, MapAccess,
21 SeqAccess, VariantAccess, Visitor
24 #[derive(Error,Debug)]
26 #[error("deserialize failed (improper TOML structure?): {0}")]
28 #[error("file has invalid TOML syntax: {0}")]
29 TomlSyntax(toml::de::Error),
32 impl serde::de::Error for Error {
33 fn custom<X: Display>(x: X) -> Self {
34 Error::Custom(x.to_string().into_boxed_str())
38 fn str_deserialize<'de, S: DeserializeSeed<'de>>
39 (seed: S, k: &'de str) -> Result<S::Value, Error>
46 pub struct TomlDe<'de>(pub &'de toml::Value);
48 struct SA<'de>(slice::Iter<'de, toml::Value>);
50 impl<'de> SeqAccess<'de> for SA<'de> {
53 fn next_element_seed<T: DeserializeSeed<'de>>
54 (&mut self, seed: T) -> Option<T::Value>
56 if let Some(elem) = (self.0).next() {
57 Some(seed.deserialize(TomlDe(elem))?)
62 fn size_hint(&self) -> Option<usize> {
67 struct MA<'de>(Peekable<toml::map::Iter<'de>>);
69 impl<'de> MapAccess<'de> for MA<'de> {
71 fn next_key_seed<K: DeserializeSeed<'de>>
72 (&mut self, seed: K) -> Result<Option<K::Value>, Error>
74 Ok(if let Some((k, _v)) = self.0.peek() {
75 Some(str_deserialize(seed, k)?)
81 fn next_value_seed<V: DeserializeSeed<'de>>
82 (&mut self, seed: V) -> V::Value
84 let (_k, v) = self.0.next().unwrap();
85 seed.deserialize(TomlDe(v))?
89 struct EA<'de> { k: &'de str, v: &'de toml::Value }
91 impl<'de> EnumAccess<'de> for EA<'de> {
93 type Variant = TomlDe<'de>;
95 fn variant_seed<V: DeserializeSeed<'de>>
96 (self, seed: V) -> (V::Value, TomlDe<'de>)
98 (str_deserialize(seed, self.k)?,
103 impl<'de> VariantAccess<'de> for TomlDe<'de> {
106 fn unit_variant(self) { }
109 fn newtype_variant_seed<S: DeserializeSeed<'de>>
110 (self, seed: S) -> S::Value
112 seed.deserialize(self)?
116 fn tuple_variant<V: Visitor<'de>>(self, _: usize, v: V) -> V::Value {
121 fn struct_variant<V: Visitor<'de>>(self, _:&[&str], v: V) -> V::Value {
127 fn visit<'de, V: Visitor<'de>>(v: V, tv: &'de toml::Value) -> V::Value {
128 type TV = toml::Value;
130 TV::String(s) => v.visit_borrowed_str::<Error>(s)?,
131 &TV::Integer(i) => v.visit_i64::<Error>(i)?,
132 &TV::Float(f) => v.visit_f64::<Error>(f)?,
133 &TV::Boolean(b) => v.visit_bool::<Error>(b)?,
134 TV::Datetime(dt) => v.visit_str::<Error>(&dt.to_string())?,
135 TV::Array(a) => v.visit_seq(SA(a.as_slice().iter()))?,
136 TV::Table(t) => v.visit_map(MA(t.iter().peekable()))?,
140 impl<'de> Deserializer<'de> for TomlDe<'de> {
143 fn deserialize_any<V: Visitor<'de>>(self, visitor: V) -> V::Value {
144 visit(visitor, self.0)?
147 fn deserialize_option<V: Visitor<'de>>(self, visitor: V) -> V::Value {
148 // Option only works in structs, where it's represented by an
149 // absence of the key. When we are called, we are either in a
150 // non-working context, or a context where we've already had
151 // the relevant struct key.
152 visitor.visit_some(self)?
155 fn deserialize_enum<V: Visitor<'de>>
156 (self, _:&str, _:&[&str], vi: V) -> V::Value
158 type TV = toml::Value;
160 TV::String(s) => return vi.visit_enum(s.as_str().into_deserializer())?,
161 TV::Table(s) => if_chain! {
162 let mut s = s.iter();
163 if let Some((k, v)) = s.next();
164 if let None = s.next();
165 then { return vi.visit_enum(EA { k, v }) }
169 // hopefully the format will figure it out, or produce an error
172 forward_to_deserialize_any! {
173 bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
174 bytes byte_buf unit unit_struct newtype_struct seq tuple
175 tuple_struct map struct identifier ignored_any
180 pub fn from_value<'de, T: Deserialize<'de>>(tv: &'de toml::Value) -> T {
181 Deserialize::deserialize(TomlDe(tv))?
185 pub fn from_str<T: DeserializeOwned>(s: &str) -> T {
186 let tv: toml::Value = s.parse().map_err(Error::TomlSyntax)?;
192 pub fn from_slice<T: DeserializeOwned>(s: &[u8]) -> T {
193 let tv: toml::Value = toml::de::from_slice(s).map_err(Error::TomlSyntax)?;