Proof of concept: reporting span information to a Spanned<T> type

This commit is contained in:
David Tolnay 2018-05-05 14:41:57 -07:00 committed by John-John Tedro
parent 24d0f25427
commit 6db43965f9
4 changed files with 178 additions and 52 deletions

View file

@ -20,7 +20,7 @@ travis-ci = { repository = "alexcrichton/toml-rs" }
[dependencies]
serde = "1.0"
serde_derive = "1.0"
[dev-dependencies]
serde_derive = "1.0"
serde_json = "1.0"

175
src/de.rs
View file

@ -13,8 +13,9 @@ use std::vec;
use serde::de;
use serde::de::IntoDeserializer;
use tokens::{Tokenizer, Token, Error as TokenError};
use tokens::{Tokenizer, Token, Error as TokenError, Span};
use datetime::{SERDE_STRUCT_FIELD_NAME, SERDE_STRUCT_NAME};
use spanned;
/// Deserializes a byte slice into a type.
///
@ -238,7 +239,7 @@ impl<'de, 'b> de::Deserializer<'de> for &'b mut Deserializer<'de> {
{
if let Some(next) = self.next()? {
match next {
Token::String { val, .. } => {
(_, Token::String { val, .. }) => {
visitor.visit_enum(val.into_deserializer())
},
_ => Err(Error::from_kind(ErrorKind::ExpectedString))
@ -504,23 +505,23 @@ impl<'de> de::Deserializer<'de> for ValueDeserializer<'de> {
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
where V: de::Visitor<'de>,
{
match self.value {
Value::Integer(i) => visitor.visit_i64(i),
Value::Boolean(b) => visitor.visit_bool(b),
Value::Float(f) => visitor.visit_f64(f),
Value::String(Cow::Borrowed(s)) => visitor.visit_borrowed_str(s),
Value::String(Cow::Owned(s)) => visitor.visit_string(s),
Value::Datetime(s) => visitor.visit_map(DatetimeDeserializer {
match self.value.e {
E::Integer(i) => visitor.visit_i64(i),
E::Boolean(b) => visitor.visit_bool(b),
E::Float(f) => visitor.visit_f64(f),
E::String(Cow::Borrowed(s)) => visitor.visit_borrowed_str(s),
E::String(Cow::Owned(s)) => visitor.visit_string(s),
E::Datetime(s) => visitor.visit_map(DatetimeDeserializer {
date: s,
visited: false,
}),
Value::Array(values) => {
E::Array(values) => {
let mut s = de::value::SeqDeserializer::new(values.into_iter());
let ret = visitor.visit_seq(&mut s)?;
s.end()?;
Ok(ret)
}
Value::InlineTable(values) => {
E::InlineTable(values) => {
visitor.visit_map(InlineTableDeserializer {
values: values.into_iter(),
next_value: None,
@ -536,7 +537,7 @@ impl<'de> de::Deserializer<'de> for ValueDeserializer<'de> {
where V: de::Visitor<'de>,
{
if name == SERDE_STRUCT_NAME && fields == &[SERDE_STRUCT_FIELD_NAME] {
if let Value::Datetime(s) = self.value {
if let E::Datetime(s) = self.value.e {
return visitor.visit_map(DatetimeDeserializer {
date: s,
visited: false,
@ -544,6 +545,16 @@ impl<'de> de::Deserializer<'de> for ValueDeserializer<'de> {
}
}
if name == spanned::NAME && fields == spanned::FIELDS {
let start = self.value.start;
let end = self.value.end;
return visitor.visit_map(SpannedDeserializer {
start: Some(start),
value: Some(self.value),
end: Some(end),
});
}
self.deserialize_any(visitor)
}
@ -563,8 +574,8 @@ impl<'de> de::Deserializer<'de> for ValueDeserializer<'de> {
) -> Result<V::Value, Error>
where V: de::Visitor<'de>
{
match self.value {
Value::String(val) => visitor.visit_enum(val.into_deserializer()),
match self.value.e {
E::String(val) => visitor.visit_enum(val.into_deserializer()),
_ => Err(Error::from_kind(ErrorKind::ExpectedString))
}
}
@ -594,6 +605,46 @@ impl<'de> de::IntoDeserializer<'de, Error> for Value<'de> {
}
}
struct SpannedDeserializer<'a> {
start: Option<usize>,
value: Option<Value<'a>>,
end: Option<usize>,
}
impl<'de> de::MapAccess<'de> for SpannedDeserializer<'de> {
type Error = Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Error>
where
K: de::DeserializeSeed<'de>,
{
if self.start.is_some() {
seed.deserialize("start".into_deserializer()).map(Some)
} else if self.value.is_some() {
seed.deserialize("value".into_deserializer()).map(Some)
} else if self.end.is_some() {
seed.deserialize("end".into_deserializer()).map(Some)
} else {
Ok(None)
}
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Error>
where
V: de::DeserializeSeed<'de>,
{
if let Some(start) = self.start.take() {
seed.deserialize(start.into_deserializer())
} else if let Some(value) = self.value.take() {
seed.deserialize(value.into_deserializer())
} else if let Some(end) = self.end.take() {
seed.deserialize(end.into_deserializer())
} else {
panic!("next_value_seed called before next_key_seed")
}
}
}
struct DatetimeDeserializer<'a> {
visited: bool,
date: &'a str,
@ -707,7 +758,7 @@ impl<'a> Deserializer<'a> {
}
match self.peek()? {
Some(Token::LeftBracket) => self.table_header().map(Some),
Some((_, Token::LeftBracket)) => self.table_header().map(Some),
Some(_) => self.key_value().map(Some),
None => Ok(None),
}
@ -725,13 +776,13 @@ impl<'a> Deserializer<'a> {
} else {
loop {
match self.next()? {
Some(Token::RightBracket) => {
Some((_, Token::RightBracket)) => {
if array {
self.eat(Token::RightBracket)?;
}
break
}
Some(Token::Newline) |
Some((_, Token::Newline)) |
None => break,
_ => {}
}
@ -759,17 +810,27 @@ impl<'a> Deserializer<'a> {
fn value(&mut self) -> Result<Value<'a>, Error> {
let at = self.tokens.current();
let value = match self.next()? {
Some(Token::String { val, .. }) => Value::String(val),
Some(Token::Keylike("true")) => Value::Boolean(true),
Some(Token::Keylike("false")) => Value::Boolean(false),
Some(Token::Keylike(key)) => self.number_or_date(key)?,
Some(Token::Plus) => self.number_leading_plus()?,
Some(Token::LeftBrace) => self.inline_table().map(Value::InlineTable)?,
Some(Token::LeftBracket) => self.array().map(Value::Array)?,
Some((Span { start, end }, Token::String { val, .. })) => {
Value { e: E::String(val), start, end }
}
Some((Span { start, end }, Token::Keylike("true"))) => {
Value { e: E::Boolean(true), start, end }
}
Some((Span { start, end }, Token::Keylike("false"))) => {
Value { e: E::Boolean(false), start, end }
}
Some((_, Token::Keylike(key))) => self.number_or_date(key)?,
Some((_, Token::Plus)) => self.number_leading_plus()?,
Some((Span { start, end }, Token::LeftBrace)) => {
self.inline_table().map(|table| Value { e: E::InlineTable(table), start, end })?
}
Some((Span { start, end }, Token::LeftBracket)) => {
self.array().map(|array| Value { e: E::Array(array), start, end })?
}
Some(token) => {
return Err(self.error(at, ErrorKind::Wanted {
expected: "a value",
found: token.describe(),
found: token.1.describe(),
}))
}
None => return Err(self.eof()),
@ -780,9 +841,11 @@ impl<'a> Deserializer<'a> {
fn number_or_date(&mut self, s: &'a str) -> Result<Value<'a>, Error> {
if s.contains('T') || (s.len() > 1 && s[1..].contains('-')) &&
!s.contains("e-") {
self.datetime(s, false).map(Value::Datetime)
// FIXME needs span
self.datetime(s, false).map(|d| Value { e: E::Datetime(d), start: 0, end: 0 })
} else if self.eat(Token::Colon)? {
self.datetime(s, true).map(Value::Datetime)
// FIXME needs span
self.datetime(s, true).map(|d| Value { e: E::Datetime(d), start: 0, end: 0 })
} else {
self.number(s)
}
@ -790,24 +853,27 @@ impl<'a> Deserializer<'a> {
fn number(&mut self, s: &'a str) -> Result<Value<'a>, Error> {
if s.contains('e') || s.contains('E') {
self.float(s, None).map(Value::Float)
// FIXME needs span
self.float(s, None).map(|f| Value { e: E::Float(f), start: 0, end: 0 })
} else if self.eat(Token::Period)? {
let at = self.tokens.current();
match self.next()? {
Some(Token::Keylike(after)) => {
self.float(s, Some(after)).map(Value::Float)
Some((_, Token::Keylike(after))) => {
// FIXME needs span
self.float(s, Some(after)).map(|f| Value { e: E::Float(f), start: 0, end: 0 })
}
_ => Err(self.error(at, ErrorKind::NumberInvalid)),
}
} else {
self.integer(s).map(Value::Integer)
// FIXME needs span
self.integer(s).map(|f| Value { e: E::Integer(f), start: 0, end: 0 })
}
}
fn number_leading_plus(&mut self) -> Result<Value<'a>, Error> {
let start = self.tokens.current();
match self.next()? {
Some(Token::Keylike(s)) => self.number(s),
Some((_, Token::Keylike(s))) => self.number(s),
_ => Err(self.error(start, ErrorKind::NumberInvalid)),
}
}
@ -884,7 +950,7 @@ impl<'a> Deserializer<'a> {
let (a, b) = if suffix.len() == 1 {
self.eat(Token::Plus)?;
match self.next()? {
Some(Token::Keylike(s)) => {
Some((_, Token::Keylike(s))) => {
self.parse_integer(s, false, false)?
}
_ => return Err(self.error(start, ErrorKind::NumberInvalid)),
@ -927,19 +993,19 @@ impl<'a> Deserializer<'a> {
if colon_eaten || self.eat(Token::Colon)? {
// minutes
match self.next()? {
Some(Token::Keylike(_)) => {}
Some((_, Token::Keylike(_))) => {}
_ => return Err(self.error(start, ErrorKind::DateInvalid)),
}
// Seconds
self.expect(Token::Colon)?;
match self.next()? {
Some(Token::Keylike(_)) => {}
Some((_, Token::Keylike(_))) => {}
_ => return Err(self.error(start, ErrorKind::DateInvalid)),
}
// Fractional seconds
if self.eat(Token::Period)? {
match self.next()? {
Some(Token::Keylike(_)) => {}
Some((_, Token::Keylike(_))) => {}
_ => return Err(self.error(start, ErrorKind::DateInvalid)),
}
}
@ -947,13 +1013,13 @@ impl<'a> Deserializer<'a> {
// offset
if self.eat(Token::Plus)? {
match self.next()? {
Some(Token::Keylike(_)) => {}
Some((_, Token::Keylike(_))) => {}
_ => return Err(self.error(start, ErrorKind::DateInvalid)),
}
}
if self.eat(Token::Colon)? {
match self.next()? {
Some(Token::Keylike(_)) => {}
Some((_, Token::Keylike(_))) => {}
_ => return Err(self.error(start, ErrorKind::DateInvalid)),
}
}
@ -1048,12 +1114,12 @@ impl<'a> Deserializer<'a> {
self.tokens.expect(expected).map_err(|e| self.token_error(e))
}
fn next(&mut self) -> Result<Option<Token<'a>>, Error> {
self.tokens.next().map(|t| t.map(|t| t.1)).map_err(|e| self.token_error(e))
fn next(&mut self) -> Result<Option<(Span, Token<'a>)>, Error> {
self.tokens.next().map_err(|e| self.token_error(e))
}
fn peek(&mut self) -> Result<Option<Token<'a>>, Error> {
self.tokens.peek().map(|t| t.map(|t| t.1)).map_err(|e| self.token_error(e))
fn peek(&mut self) -> Result<Option<(Span, Token<'a>)>, Error> {
self.tokens.peek().map_err(|e| self.token_error(e))
}
fn eof(&self) -> Error {
@ -1300,7 +1366,14 @@ impl<'a> Header<'a> {
}
#[derive(Debug)]
enum Value<'a> {
struct Value<'a> {
e: E<'a>,
start: usize,
end: usize,
}
#[derive(Debug)]
enum E<'a> {
Integer(i64),
Float(f64),
Boolean(bool),
@ -1312,14 +1385,14 @@ enum Value<'a> {
impl<'a> Value<'a> {
fn same_type(&self, other: &Value<'a>) -> bool {
match (self, other) {
(&Value::String(..), &Value::String(..)) |
(&Value::Integer(..), &Value::Integer(..)) |
(&Value::Float(..), &Value::Float(..)) |
(&Value::Boolean(..), &Value::Boolean(..)) |
(&Value::Datetime(..), &Value::Datetime(..)) |
(&Value::Array(..), &Value::Array(..)) |
(&Value::InlineTable(..), &Value::InlineTable(..)) => true,
match (&self.e, &other.e) {
(&E::String(..), &E::String(..)) |
(&E::Integer(..), &E::Integer(..)) |
(&E::Float(..), &E::Float(..)) |
(&E::Boolean(..), &E::Boolean(..)) |
(&E::Datetime(..), &E::Datetime(..)) |
(&E::Array(..), &E::Array(..)) |
(&E::InlineTable(..), &E::InlineTable(..)) => true,
_ => false,
}

View file

@ -153,6 +153,8 @@
#[macro_use]
extern crate serde;
#[macro_use]
extern crate serde_derive;
pub mod value;
#[doc(no_inline)]
@ -169,3 +171,5 @@ mod tokens;
#[doc(hidden)]
pub mod macros;
pub mod spanned;

49
src/spanned.rs Normal file
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@ -0,0 +1,49 @@
//! ```
//! #[macro_use]
//! extern crate serde_derive;
//!
//! extern crate toml;
//! use toml::spanned::Spanned;
//!
//! #[derive(Deserialize)]
//! struct Udoprog {
//! s: Spanned<String>,
//! }
//!
//! fn main() {
//! let t = "s = \"udoprog\"\n";
//!
//! let u: Udoprog = toml::from_str(t).unwrap();
//!
//! assert_eq!(u.s.start, 4);
//! assert_eq!(u.s.end, 13);
//! }
//! ```
use serde::{Serialize, Serializer};
// FIXME: use a more unique name like "toml::Spanned".
#[doc(hidden)]
pub const NAME: &str = "Spanned";
#[doc(hidden)]
pub const FIELDS: &[&str] = &["value", "start", "end"];
///
#[derive(Deserialize, Debug)]
pub struct Spanned<T> {
///
pub value: T,
///
pub start: usize,
///
pub end: usize,
}
impl<T: Serialize> Serialize for Spanned<T> {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
self.value.serialize(serializer)
}
}