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git-config/src/de.rs

410 lines
9.6 KiB
Rust

use std::ops::{AddAssign, MulAssign, Neg};
use crate::values::Boolean;
use crate::{
error::{Error, Result},
values::PeekParse,
};
use serde::de::{
self, DeserializeSeed, EnumAccess, IntoDeserializer, MapAccess, SeqAccess, VariantAccess,
Visitor,
};
use serde::Deserialize;
pub struct Deserializer<'de> {
// This string starts with the input data and characters are truncated off
// the beginning as data is parsed.
input: &'de str,
}
impl<'de> Deserializer<'de> {
// By convention, `Deserializer` constructors are named like `from_xyz`.
// That way basic use cases are satisfied by something like
// `serde_json::from_str(...)` while advanced use cases that require a
// deserializer can make one with `serde_json::Deserializer::from_str(...)`.
pub fn from_str(input: &'de str) -> Self {
Deserializer { input }
}
}
// By convention, the public API of a Serde deserializer is one or more
// `from_xyz` methods such as `from_str`, `from_bytes`, or `from_reader`
// depending on what Rust types the deserializer is able to consume as input.
//
// This basic deserializer supports only `from_str`.
pub fn from_str<'a, T>(s: &'a str) -> Result<T>
where
T: Deserialize<'a>,
{
let mut deserializer = Deserializer::from_str(s);
let t = T::deserialize(&mut deserializer)?;
if deserializer.input.is_empty() {
Ok(t)
} else {
todo!()
}
}
impl<'de> Deserializer<'de> {
fn peek(&mut self) -> Result<char> {
self.input.chars().next().ok_or(Error::Eof)
}
fn next(&mut self) -> Result<char> {
let ch = self.peek()?;
self.input = &self.input[ch.len_utf8()..];
Ok(ch)
}
fn parse_bool(&mut self) -> Result<bool> {
let (value, size) = Boolean::peek_parse(self.input)?;
self.input = &self.input[size..];
Ok(value)
}
fn parse_unsigned<T>(&mut self) -> Result<T> {
self.parse_int(true)
}
fn parse_signed<T>(&mut self) -> Result<T> {
self.parse_int(false)
}
fn parse_int<T>(&mut self, positive_only: bool) -> Result<T> {
self.consume_whitespace()?;
match self.next()? {
c @ '0'..='9' => {
let mut significand = (c as u8 - b'0') as u64;
loop {
match self.peek()? {
c @ '0'..='9' => {
let digit = (c as u8 - b'0') as u64;
if significand.wrapping_mul(10).wrapping_add(digit) < u64::MAX {}
let _ = self.next();
significand = significand * 10 + digit;
}
_ => {
// return self.parse_number(positive, significand);
todo!()
}
}
}
}
_ => Err(Error::InvalidInteger),
}
}
fn consume_whitespace(&mut self) -> Result<()> {
loop {
match self.peek()? {
' ' | '\n' | '\t' | '\r' => {
let _ = self.next();
}
_ => {
return Ok(());
}
}
}
}
}
impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> {
type Error = Error;
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
match self.peek()? {
_ => todo!(),
}
}
fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_bool(self.parse_bool()?)
}
fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_i8(self.parse_signed()?)
}
fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_i16(self.parse_signed()?)
}
fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_i32(self.parse_signed()?)
}
fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_i64(self.parse_signed()?)
}
fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_u8(self.parse_unsigned()?)
}
fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_u16(self.parse_unsigned()?)
}
fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_u32(self.parse_unsigned()?)
}
fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_u64(self.parse_unsigned()?)
}
fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.deserialize_f64(visitor)
}
fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
unimplemented!("Cannot deserialize into a float value! Use a integer variant instead.")
}
fn deserialize_char<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.deserialize_str(visitor)
}
fn deserialize_str<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_string<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.deserialize_str(visitor)
}
fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_unit()
}
fn deserialize_newtype_struct<V>(self, name: &'static str, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.deserialize_seq(visitor)
}
fn deserialize_tuple_struct<V>(
self,
_name: &'static str,
_len: usize,
visitor: V,
) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.deserialize_seq(visitor)
}
fn deserialize_map<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
self.consume_whitespace()?;
Ok(visitor.visit_map(self)?)
}
fn deserialize_struct<V>(
self,
_name: &'static str,
_fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: Visitor<'de>,
{
visitor.visit_map(self)
}
fn deserialize_enum<V>(
self,
name: &'static str,
variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value>
where
V: Visitor<'de>,
{
todo!()
}
}
impl<'de, 'a> MapAccess<'de> for Deserializer<'de> {
type Error = Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
where
K: DeserializeSeed<'de>,
{
// A map section is ended when another section begins or we hit EOL.
// Therefore, we only check if a next section begins or in the case of
// EOL indicate that we're done.
if self.peek().unwrap_or('[') == '[' {
return Ok(None);
}
seed.deserialize(self).map(Some)
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value>
where
V: DeserializeSeed<'de>,
{
seed.deserialize(self)
}
}
#[cfg(test)]
mod deserialize {
use crate::from_str;
use serde_derive::Deserialize;
#[test]
fn unit() {
#[derive(Deserialize, PartialEq, Debug)]
struct Test;
assert_eq!(Test, from_str("").unwrap());
assert_eq!((), from_str("").unwrap());
}
#[test]
#[should_panic]
fn float() {
from_str::<f64>("").unwrap();
}
#[test]
fn basic() {
#[derive(Deserialize, PartialEq, Debug)]
struct Config {
user: User,
}
#[derive(Deserialize, PartialEq, Debug)]
struct User {
email: String,
name: String,
}
let expected = Config {
user: User {
email: "code@eddie.sh".to_string(),
name: "Edward Shen".to_string(),
},
};
assert_eq!(
expected,
from_str("[user]\nemail=code@eddie.sh\nname=Edward Shen\n").unwrap()
);
}
}