event casts

src/entry/table.rs

@@ -1,5 +1,6 @@
 use super::{Array, Entry};
 use crate::entry::{Statement, Value};
+use crate::event::{EntryEvent, GroupStartEvent};
 use crate::{Event, Item, Reader, Result};
 use serde::{Serialize, Serializer};
 use std::collections::hash_map;
@@ -51,21 +52,23 @@ impl Table {
 
         while let Some(event) = reader.event() {
             match event? {
-                Event::Entry {
+                Event::Entry(EntryEvent {
                     key: Item::Item { content: key, .. },
                     value,
                     ..
-                } => insert(&mut map, key, Value::from(value.into_content())),
+                }) => insert(&mut map, key, Value::from(value.into_content())),
 
-                Event::Entry {
+                Event::Entry(EntryEvent {
                     key: Item::Statement { content: key, .. },
                     value,
                     ..
-                } => insert(&mut map, key, Statement::from(value.into_content())),
+                }) => insert(&mut map, key, Statement::from(value.into_content())),
 
-                Event::GroupStart { name, .. } => insert(&mut map, name, Table::load(reader)?),
+                Event::GroupStart(GroupStartEvent { name, .. }) => {
+                    insert(&mut map, name, Table::load(reader)?)
+                }
 
-                Event::GroupEnd { .. } => break,
+                Event::GroupEnd(_) => break,
             }
         }
 

src/error.rs

@@ -1,4 +1,4 @@
-use crate::Token;
+use crate::{Event, Token};
 use miette::{Diagnostic, SourceSpan};
 use std::error::Error;
 use std::fmt::{Display, Formatter};
@@ -15,6 +15,10 @@ pub enum VdfError {
     #[diagnostic(transparent)]
     /// No valid token found
     NoValidToken(#[from] NoValidTokenError),
+    #[error(transparent)]
+    #[diagnostic(transparent)]
+    /// Wrong event to for conversion
+    WrongEntryType(#[from] WrongEventTypeError),
 }
 
 struct ExpectedTokens<'a>(&'a [Token]);
@@ -85,8 +89,9 @@ impl Display for UnexpectedTokenError {
 impl Error for UnexpectedTokenError {}
 
 /// A token that wasn't expected was found while parsing
-#[derive(Debug, Clone, Diagnostic)]
+#[derive(Debug, Clone, Diagnostic, Error)]
 #[diagnostic(code(vmt_reader::no_valid_token))]
+#[error("No valid token found, expected one of {}", ExpectedTokens(self.expected))]
 pub struct NoValidTokenError {
     #[label("Expected {}", ExpectedTokens(self.expected))]
     err_span: SourceSpan,
@@ -105,14 +110,32 @@ impl NoValidTokenError {
     }
 }
 
-impl Display for NoValidTokenError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "No valid token found, expected one of {}",
-            ExpectedTokens(self.expected)
-        )
+/// Wrong event to for conversion
+#[derive(Debug, Clone, Diagnostic, Error)]
+#[diagnostic(code(vmt_reader::wrong_value_type))]
+#[error("Wrong event to for conversion, expected a {expected} but found a {got}")]
+pub struct WrongEventTypeError {
+    pub expected: &'static str,
+    pub got: &'static str,
+    pub event: Event<'static>,
+    #[label("Expected a {}", self.expected)]
+    err_span: SourceSpan,
+    #[source_code]
+    src: String,
+}
+
+impl WrongEventTypeError {
+    pub fn new(event: Event, expected: &'static str, got: &'static str) -> Self {
+        WrongEventTypeError {
+            err_span: event.span().into(),
+            event: event.into_owned(),
+            expected,
+            got,
+            src: String::new(),
         }
     }
 
-impl Error for NoValidTokenError {}
+    pub fn with_source(self, src: String) -> Self {
+        WrongEventTypeError { src, ..self }
+    }
+}

src/event.rs

@@ -0,0 +1,155 @@
+use crate::error::WrongEventTypeError;
+use crate::VdfError;
+use logos::Span;
+use std::borrow::Cow;
+
+/// Kinds of item.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Item<'a> {
+    /// A statement, the ones starting with #.
+    Statement { content: Cow<'a, str>, span: Span },
+
+    /// A value.
+    Item { content: Cow<'a, str>, span: Span },
+}
+
+impl Item<'_> {
+    pub fn into_owned(self) -> Item<'static> {
+        match self {
+            Item::Statement { content, span } => Item::Statement {
+                content: content.into_owned().into(),
+                span,
+            },
+            Item::Item { content, span } => Item::Item {
+                content: content.into_owned().into(),
+                span,
+            },
+        }
+    }
+}
+
+impl<'a> Item<'a> {
+    pub fn span(&self) -> Span {
+        match self {
+            Item::Statement { span, .. } => span.clone(),
+            Item::Item { span, .. } => span.clone(),
+        }
+    }
+
+    pub fn into_content(self) -> Cow<'a, str> {
+        match self {
+            Item::Statement { content, .. } => content,
+            Item::Item { content, .. } => content,
+        }
+    }
+}
+
+/// Reader event.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Event<'a> {
+    /// A group with the given name is starting.
+    GroupStart(GroupStartEvent<'a>),
+
+    /// A group has ended.
+    GroupEnd(GroupEndEvent),
+
+    /// An entry.
+    Entry(EntryEvent<'a>),
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct GroupStartEvent<'a> {
+    pub name: Cow<'a, str>,
+    pub span: Span,
+}
+
+impl GroupStartEvent<'_> {
+    pub fn into_owned(self) -> GroupStartEvent<'static> {
+        GroupStartEvent {
+            name: self.name.into_owned().into(),
+            span: self.span,
+        }
+    }
+}
+
+impl<'a> TryFrom<Event<'a>> for GroupStartEvent<'a> {
+    type Error = VdfError;
+
+    fn try_from(event: Event<'a>) -> Result<Self, Self::Error> {
+        match event {
+            Event::GroupStart(event) => Ok(event),
+            Event::GroupEnd(_) => {
+                Err(WrongEventTypeError::new(event, "group start", "group end").into())
+            }
+            Event::Entry(_) => Err(WrongEventTypeError::new(event, "group start", "entry").into()),
+        }
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct GroupEndEvent {
+    pub span: Span,
+}
+
+impl<'a> TryFrom<Event<'a>> for GroupEndEvent {
+    type Error = VdfError;
+
+    fn try_from(event: Event<'a>) -> Result<Self, Self::Error> {
+        match event {
+            Event::GroupEnd(event) => Ok(event),
+            Event::GroupStart(_) => {
+                Err(WrongEventTypeError::new(event, "group end", "group start").into())
+            }
+            Event::Entry(_) => Err(WrongEventTypeError::new(event, "group start", "entry").into()),
+        }
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct EntryEvent<'a> {
+    pub key: Item<'a>,
+    pub value: Item<'a>,
+    pub span: Span,
+}
+
+impl EntryEvent<'_> {
+    pub fn into_owned(self) -> EntryEvent<'static> {
+        EntryEvent {
+            key: self.key.into_owned(),
+            value: self.value.into_owned(),
+            span: self.span,
+        }
+    }
+}
+
+impl<'a> TryFrom<Event<'a>> for EntryEvent<'a> {
+    type Error = VdfError;
+
+    fn try_from(event: Event<'a>) -> Result<Self, Self::Error> {
+        match event {
+            Event::Entry(event) => Ok(event),
+            Event::GroupEnd(_) => Err(WrongEventTypeError::new(event, "entry", "group end").into()),
+            Event::GroupStart(_) => {
+                Err(WrongEventTypeError::new(event, "entry", "group start").into())
+            }
+        }
+    }
+}
+
+impl Event<'_> {
+    #[allow(dead_code)]
+    pub fn span(&self) -> Span {
+        match self {
+            Event::GroupStart(GroupStartEvent { span, .. }) => span.clone(),
+            Event::GroupEnd(GroupEndEvent { span, .. }) => span.clone(),
+            Event::Entry(EntryEvent { span, .. }) => span.clone(),
+        }
+    }
+    pub fn into_owned(self) -> Event<'static> {
+        match self {
+            Event::GroupStart(event) => Event::GroupStart(event.into_owned()),
+            Event::GroupEnd(event) => Event::GroupEnd(event),
+            Event::Entry(event) => Event::Entry(event.into_owned()),
+        }
+    }
+}

src/lib.rs

@@ -1,10 +1,12 @@
 pub mod entry;
 mod error;
+mod event;
 mod parser;
 mod reader;
 
 pub use error::VdfError;
 
 pub type Result<T, E = VdfError> = std::result::Result<T, E>;
+pub use event::{EntryEvent, Event, GroupEndEvent, GroupStartEvent, Item};
 pub use parser::Token;
-pub use reader::{Event, Item, Reader};
+pub use reader::Reader;

src/reader.rs

@@ -1,65 +1,12 @@
 use super::{Result, Token};
 use crate::error::{NoValidTokenError, UnexpectedTokenError};
+use crate::event::{EntryEvent, Event, GroupEndEvent, GroupStartEvent, Item};
 use logos::{Lexer, Logos, Span, SpannedIter};
 use std::borrow::Cow;
 
-/// Kinds of item.
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum Item<'a> {
-    /// A statement, the ones starting with #.
-    Statement { content: Cow<'a, str>, span: Span },
-
-    /// A value.
-    Item { content: Cow<'a, str>, span: Span },
-}
-
-impl<'a> Item<'a> {
-    pub fn span(&self) -> Span {
-        match self {
-            Item::Statement { span, .. } => span.clone(),
-            Item::Item { span, .. } => span.clone(),
-        }
-    }
-
-    pub fn into_content(self) -> Cow<'a, str> {
-        match self {
-            Item::Statement { content, .. } => content,
-            Item::Item { content, .. } => content,
-        }
-    }
-}
-
-/// Reader event.
-#[derive(Clone, PartialEq, Eq, Debug)]
-pub enum Event<'a> {
-    /// A group with the given name is starting.
-    GroupStart { name: Cow<'a, str>, span: Span },
-
-    /// A group has ended.
-    GroupEnd { span: Span },
-
-    /// An entry.
-    Entry {
-        key: Item<'a>,
-        value: Item<'a>,
-        span: Span,
-    },
-}
-
-impl Event<'_> {
-    #[allow(dead_code)]
-    pub fn span(&self) -> Span {
-        match self {
-            Event::GroupStart { span, .. } => span.clone(),
-            Event::GroupEnd { span, .. } => span.clone(),
-            Event::Entry { span, .. } => span.clone(),
-        }
-    }
-}
-
 /// A VDF token reader.
 pub struct Reader<'a> {
-    pub(crate) content: &'a str,
+    pub source: &'a str,
     lexer: SpannedIter<'a, Token>,
     peeked: Option<(Result<Token, <Token as Logos<'a>>::Error>, Span)>,
 }
@@ -67,7 +14,7 @@ pub struct Reader<'a> {
 impl<'a> From<&'a str> for Reader<'a> {
     fn from(content: &'a str) -> Self {
         Reader {
-            content,
+            source: content,
             lexer: Lexer::new(content).spanned(),
             peeked: None,
         }
@@ -90,6 +37,10 @@ impl<'a> Reader<'a> {
         self.peeked.clone()
     }
 
+    pub fn span(&self) -> Span {
+        self.lexer.span()
+    }
+
     fn token_eat_newlines(&mut self) -> Option<(Result<Token, <Token as Logos>::Error>, Span)> {
         loop {
             let (token, span) = self.token()?;
@@ -122,11 +73,13 @@ impl<'a> Reader<'a> {
                 return Some(Err(NoValidTokenError::new(
                     VALID_KEY,
                     span.into(),
-                    self.content.into(),
+                    self.source.into(),
                 )
                 .into()));
             }
-            Some((Ok(Token::GroupEnd), span)) => return Some(Ok(Event::GroupEnd { span })),
+            Some((Ok(Token::GroupEnd), span)) => {
+                return Some(Ok(Event::GroupEnd(GroupEndEvent { span })))
+            }
 
             Some((Ok(Token::Item), span)) => Item::Item {
                 content: string(self.lexer.slice()),
@@ -153,7 +106,7 @@ impl<'a> Reader<'a> {
                     VALID_KEY,
                     Some(token),
                     span.into(),
-                    self.content.into(),
+                    self.source.into(),
                 )
                 .into()))
             }
@@ -175,7 +128,7 @@ impl<'a> Reader<'a> {
                             &[Token::GroupStart],
                             Some(token),
                             span.into(),
-                            self.content.into(),
+                            self.source.into(),
                         )
                         .into()))
                     }
@@ -183,7 +136,7 @@ impl<'a> Reader<'a> {
                         return Some(Err(NoValidTokenError::new(
                             VALID_VALUE,
                             span.into(),
-                            self.content.into(),
+                            self.source.into(),
                         )
                         .into()));
                     }
@@ -192,7 +145,7 @@ impl<'a> Reader<'a> {
                             VALID_VALUE,
                             None,
                             span.into(),
-                            self.content.into(),
+                            self.source.into(),
                         )
                         .into()))
                     }
@@ -206,7 +159,7 @@ impl<'a> Reader<'a> {
                     VALID_VALUE,
                     None,
                     self.lexer.span().into(),
-                    self.content.into(),
+                    self.source.into(),
                 )
                 .into()));
             }
@@ -215,16 +168,16 @@ impl<'a> Reader<'a> {
                 return Some(Err(NoValidTokenError::new(
                     VALID_VALUE,
                     span.into(),
-                    self.content.into(),
+                    self.source.into(),
                 )
                 .into()));
             }
 
             Some((Ok(Token::GroupStart), span)) => {
-                return Some(Ok(Event::GroupStart {
+                return Some(Ok(Event::GroupStart(GroupStartEvent {
                     name: key.into_content(),
                     span,
-                }))
+                })))
             }
 
             Some((Ok(Token::QuotedItem), span)) => Item::Item {
@@ -252,14 +205,14 @@ impl<'a> Reader<'a> {
                     VALID_VALUE,
                     Some(token),
                     span.into(),
-                    self.content.into(),
+                    self.source.into(),
                 )
                 .into()))
             }
         };
 
         let span = key.span().start..value.span().end;
-        Some(Ok(Event::Entry { key, value, span }))
+        Some(Ok(Event::Entry(EntryEvent { key, value, span })))
     }
 }