diff options
Diffstat (limited to 'src/de.rs')
| -rw-r--r-- | src/de.rs | 204 |
1 files changed, 92 insertions, 112 deletions
@@ -1,59 +1,53 @@ +use crate::error::Error; +use crate::token::Token; use serde::de::value::{MapAccessDeserializer, SeqAccessDeserializer}; use serde::de::{ self, Deserialize, DeserializeSeed, EnumAccess, IntoDeserializer, MapAccess, SeqAccess, VariantAccess, Visitor, }; - -use error::Error; -use token::Token; +use serde::forward_to_deserialize_any; #[derive(Debug)] pub struct Deserializer<'de> { tokens: &'de [Token], } -macro_rules! assert_next_token { - ($de:expr, $expected:expr) => { - match $de.next_token_opt() { - Some(token) if token == $expected => {} - Some(other) => panic!( - "expected Token::{} but deserialization wants Token::{}", - other, $expected - ), - None => panic!( - "end of tokens but deserialization wants Token::{}", - $expected - ), - } - }; +fn assert_next_token(de: &mut Deserializer, expected: Token) -> Result<(), Error> { + match de.next_token_opt() { + Some(token) if token == expected => Ok(()), + Some(other) => Err(de::Error::custom(format!( + "expected Token::{} but deserialization wants Token::{}", + other, expected, + ))), + None => Err(de::Error::custom(format!( + "end of tokens but deserialization wants Token::{}", + expected, + ))), + } } -macro_rules! unexpected { - ($token:expr) => { - panic!("deserialization did not expect this token: {}", $token) - }; +fn unexpected(token: Token) -> Error { + de::Error::custom(format!( + "deserialization did not expect this token: {}", + token, + )) } -macro_rules! end_of_tokens { - () => { - panic!("ran out of tokens to deserialize") - }; +fn end_of_tokens() -> Error { + de::Error::custom("ran out of tokens to deserialize") } impl<'de> Deserializer<'de> { pub fn new(tokens: &'de [Token]) -> Self { - Deserializer { tokens: tokens } + Deserializer { tokens } } fn peek_token_opt(&self) -> Option<Token> { - self.tokens.first().cloned() + self.tokens.first().copied() } - fn peek_token(&self) -> Token { - match self.peek_token_opt() { - Some(token) => token, - None => end_of_tokens!(), - } + fn peek_token(&self) -> Result<Token, Error> { + self.peek_token_opt().ok_or_else(end_of_tokens) } pub fn next_token_opt(&mut self) -> Option<Token> { @@ -66,14 +60,10 @@ impl<'de> Deserializer<'de> { } } - fn next_token(&mut self) -> Token { - match self.tokens.split_first() { - Some((&first, rest)) => { - self.tokens = rest; - first - } - None => end_of_tokens!(), - } + fn next_token(&mut self) -> Result<Token, Error> { + let (&first, rest) = self.tokens.split_first().ok_or_else(end_of_tokens)?; + self.tokens = rest; + Ok(first) } pub fn remaining(&self) -> usize { @@ -89,12 +79,8 @@ impl<'de> Deserializer<'de> { where V: Visitor<'de>, { - let value = visitor.visit_seq(DeserializerSeqVisitor { - de: self, - len: len, - end: end, - })?; - assert_next_token!(self, end); + let value = visitor.visit_seq(DeserializerSeqVisitor { de: self, len, end })?; + assert_next_token(self, end)?; Ok(value) } @@ -107,12 +93,8 @@ impl<'de> Deserializer<'de> { where V: Visitor<'de>, { - let value = visitor.visit_map(DeserializerMapVisitor { - de: self, - len: len, - end: end, - })?; - assert_next_token!(self, end); + let value = visitor.visit_map(DeserializerMapVisitor { de: self, len, end })?; + assert_next_token(self, end)?; Ok(value) } } @@ -129,7 +111,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - let token = self.next_token(); + let token = self.next_token()?; match token { Token::Bool(v) => visitor.visit_bool(v), Token::I8(v) => visitor.visit_i8(v), @@ -161,50 +143,50 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { Token::Map { len } => self.visit_map(len, Token::MapEnd, visitor), Token::Struct { len, .. } => self.visit_map(Some(len), Token::StructEnd, visitor), Token::Enum { .. } => { - let variant = self.next_token(); - let next = self.peek_token(); + let variant = self.next_token()?; + let next = self.peek_token()?; match (variant, next) { (Token::Str(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_str(variant) } (Token::BorrowedStr(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_borrowed_str(variant) } (Token::String(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_string(variant.to_string()) } (Token::Bytes(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_bytes(variant) } (Token::BorrowedBytes(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_borrowed_bytes(variant) } (Token::ByteBuf(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_byte_buf(variant.to_vec()) } (Token::U8(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_u8(variant) } (Token::U16(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_u16(variant) } (Token::U32(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_u32(variant) } (Token::U64(variant), Token::Unit) => { - self.next_token(); + self.next_token()?; visitor.visit_u64(variant) } - (variant, Token::Unit) => unexpected!(variant), + (variant, Token::Unit) => Err(unexpected(variant)), (variant, _) => { visitor.visit_map(EnumMapVisitor::new(self, variant, EnumFormat::Any)) } @@ -232,9 +214,7 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { | Token::MapEnd | Token::StructEnd | Token::TupleVariantEnd - | Token::StructVariantEnd => { - unexpected!(token); - } + | Token::StructVariantEnd => Err(unexpected(token)), } } @@ -242,13 +222,13 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::Unit | Token::None => { - self.next_token(); + self.next_token()?; visitor.visit_none() } Token::Some => { - self.next_token(); + self.next_token()?; visitor.visit_some(self) } _ => self.deserialize_any(visitor), @@ -264,9 +244,9 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::Enum { name: n } if name == n => { - self.next_token(); + self.next_token()?; visitor.visit_enum(DeserializerEnumVisitor { de: self }) } @@ -286,9 +266,9 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::UnitStruct { .. } => { - assert_next_token!(self, Token::UnitStruct { name: name }); + assert_next_token(self, Token::UnitStruct { name })?; visitor.visit_unit() } _ => self.deserialize_any(visitor), @@ -303,9 +283,9 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::NewtypeStruct { .. } => { - assert_next_token!(self, Token::NewtypeStruct { name: name }); + assert_next_token(self, Token::NewtypeStruct { name })?; visitor.visit_newtype_struct(self) } _ => self.deserialize_any(visitor), @@ -316,21 +296,21 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::Unit | Token::UnitStruct { .. } => { - self.next_token(); + self.next_token()?; visitor.visit_unit() } Token::Seq { .. } => { - self.next_token(); + self.next_token()?; self.visit_seq(Some(len), Token::SeqEnd, visitor) } Token::Tuple { .. } => { - self.next_token(); + self.next_token()?; self.visit_seq(Some(len), Token::TupleEnd, visitor) } Token::TupleStruct { .. } => { - self.next_token(); + self.next_token()?; self.visit_seq(Some(len), Token::TupleStructEnd, visitor) } _ => self.deserialize_any(visitor), @@ -346,25 +326,25 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::Unit => { - self.next_token(); + self.next_token()?; visitor.visit_unit() } Token::UnitStruct { .. } => { - assert_next_token!(self, Token::UnitStruct { name: name }); + assert_next_token(self, Token::UnitStruct { name })?; visitor.visit_unit() } Token::Seq { .. } => { - self.next_token(); + self.next_token()?; self.visit_seq(Some(len), Token::SeqEnd, visitor) } Token::Tuple { .. } => { - self.next_token(); + self.next_token()?; self.visit_seq(Some(len), Token::TupleEnd, visitor) } Token::TupleStruct { len: n, .. } => { - assert_next_token!(self, Token::TupleStruct { name: name, len: n }); + assert_next_token(self, Token::TupleStruct { name, len: n })?; self.visit_seq(Some(len), Token::TupleStructEnd, visitor) } _ => self.deserialize_any(visitor), @@ -380,13 +360,13 @@ impl<'de, 'a> de::Deserializer<'de> for &'a mut Deserializer<'de> { where V: Visitor<'de>, { - match self.peek_token() { + match self.peek_token()? { Token::Struct { len: n, .. } => { - assert_next_token!(self, Token::Struct { name: name, len: n }); + assert_next_token(self, Token::Struct { name, len: n })?; self.visit_map(Some(fields.len()), Token::StructEnd, visitor) } Token::Map { .. } => { - self.next_token(); + self.next_token()?; self.visit_map(Some(fields.len()), Token::MapEnd, visitor) } _ => self.deserialize_any(visitor), @@ -476,7 +456,7 @@ impl<'de, 'a> EnumAccess<'de> for DeserializerEnumVisitor<'a, 'de> { where V: DeserializeSeed<'de>, { - match self.de.peek_token() { + match self.de.peek_token()? { Token::UnitVariant { variant: v, .. } | Token::NewtypeVariant { variant: v, .. } | Token::TupleVariant { variant: v, .. } @@ -497,9 +477,9 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> { type Error = Error; fn unit_variant(self) -> Result<(), Error> { - match self.de.peek_token() { + match self.de.peek_token()? { Token::UnitVariant { .. } => { - self.de.next_token(); + self.de.next_token()?; Ok(()) } _ => Deserialize::deserialize(self.de), @@ -510,9 +490,9 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> { where T: DeserializeSeed<'de>, { - match self.de.peek_token() { + match self.de.peek_token()? { Token::NewtypeVariant { .. } => { - self.de.next_token(); + self.de.next_token()?; seed.deserialize(self.de) } _ => seed.deserialize(self.de), @@ -523,26 +503,26 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> { where V: Visitor<'de>, { - match self.de.peek_token() { + match self.de.peek_token()? { Token::TupleVariant { len: enum_len, .. } => { - let token = self.de.next_token(); + let token = self.de.next_token()?; if len == enum_len { self.de .visit_seq(Some(len), Token::TupleVariantEnd, visitor) } else { - unexpected!(token); + Err(unexpected(token)) } } Token::Seq { len: Some(enum_len), } => { - let token = self.de.next_token(); + let token = self.de.next_token()?; if len == enum_len { self.de.visit_seq(Some(len), Token::SeqEnd, visitor) } else { - unexpected!(token); + Err(unexpected(token)) } } _ => de::Deserializer::deserialize_any(self.de, visitor), @@ -557,27 +537,27 @@ impl<'de, 'a> VariantAccess<'de> for DeserializerEnumVisitor<'a, 'de> { where V: Visitor<'de>, { - match self.de.peek_token() { + match self.de.peek_token()? { Token::StructVariant { len: enum_len, .. } => { - let token = self.de.next_token(); + let token = self.de.next_token()?; if fields.len() == enum_len { self.de .visit_map(Some(fields.len()), Token::StructVariantEnd, visitor) } else { - unexpected!(token); + Err(unexpected(token)) } } Token::Map { len: Some(enum_len), } => { - let token = self.de.next_token(); + let token = self.de.next_token()?; if fields.len() == enum_len { self.de .visit_map(Some(fields.len()), Token::MapEnd, visitor) } else { - unexpected!(token); + Err(unexpected(token)) } } _ => de::Deserializer::deserialize_any(self.de, visitor), @@ -602,9 +582,9 @@ enum EnumFormat { impl<'a, 'de> EnumMapVisitor<'a, 'de> { fn new(de: &'a mut Deserializer<'de>, variant: Token, format: EnumFormat) -> Self { EnumMapVisitor { - de: de, + de, variant: Some(variant), - format: format, + format, } } } @@ -622,7 +602,7 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> { .deserialize(BytesDeserializer { value: variant }) .map(Some), Some(Token::U32(variant)) => seed.deserialize(variant.into_deserializer()).map(Some), - Some(other) => unexpected!(other), + Some(other) => Err(unexpected(other)), None => Ok(None), } } @@ -641,7 +621,7 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> { }; seed.deserialize(SeqAccessDeserializer::new(visitor))? }; - assert_next_token!(self.de, Token::TupleVariantEnd); + assert_next_token(self.de, Token::TupleVariantEnd)?; Ok(value) } EnumFormat::Map => { @@ -653,7 +633,7 @@ impl<'de, 'a> MapAccess<'de> for EnumMapVisitor<'a, 'de> { }; seed.deserialize(MapAccessDeserializer::new(visitor))? }; - assert_next_token!(self.de, Token::StructVariantEnd); + assert_next_token(self.de, Token::StructVariantEnd)?; Ok(value) } EnumFormat::Any => seed.deserialize(&mut *self.de), |