Rewrote the parser

onihime/src/lexer/mod.rs

@@ -59,6 +59,12 @@ impl<'lexer> Lexer<'lexer> {
         Span::new(self.byte..self.byte, self.source.clone())
     }
 
+    /// Returns `true` when at the end of the input.
+    #[must_use]
+    pub(crate) fn eof(&self) -> bool {
+        self.peek(0).is_none()
+    }
+
     /// Get the current character.
     #[must_use]
     fn current(&self) -> Option<char> {

onihime/src/parser/ast.rs

@@ -4,9 +4,123 @@ use crate::{
     span::Span,
 };
 
+/// Abstract Syntax Tree (AST).
+#[derive(Debug, Default, Clone, PartialEq)]
+pub(crate) struct Ast {
+    root: Vec<Node>,
+}
+
+impl Ast {
+    /// Construct a new instance of `Ast`.
+    #[must_use]
+    pub(crate) fn new(root: Vec<Node>) -> Self {
+        Self { root }
+    }
+}
+
+impl From<Vec<Node>> for Ast {
+    fn from(root: Vec<Node>) -> Self {
+        Self { root }
+    }
+}
+
+#[cfg(not(tarpaulin_include))]
+impl std::fmt::Display for Ast {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for node in &self.root {
+            write!(f, "{node}\n")?;
+        }
+
+        Ok(())
+    }
+}
+
+/// A node in the Abstract Syntax Tree (AST).
+///
+/// `Nodes`s contain the kind of node which was found, as well as a [Span]
+/// specifying the [Source] and [Location] of the node.
+///
+/// [Source]: crate::span::Source
+/// [Location]: crate::span::Location
+#[derive(Debug, Clone, PartialEq)]
+pub(crate) struct Node {
+    /// The kind of node.
+    pub kind: Expr,
+    /// The span in which the node occurs.
+    pub span: Span,
+}
+
+impl Node {
+    /// Construct a new instance of `Node`.
+    #[must_use]
+    pub(crate) fn new(kind: Expr, span: Span) -> Self {
+        Self { kind, span }
+    }
+
+    /// Push a child node onto a list node.
+    pub(crate) fn push_node(&mut self, child: Self) -> Result<(), ParserError> {
+        match &mut self.kind {
+            Expr::List(vec) | Expr::Map(vec) | Expr::Set(vec) | Expr::Vector(vec) => {
+                vec.push(child);
+            }
+            _ => {
+                // FIXME
+                // return Err(ParserError::new(
+                //     ParserErrorKind::UnexpectedState,
+                //     child.span,
+                // ))
+                todo!()
+            }
+        }
+
+        Ok(())
+    }
+
+    #[cfg(not(tarpaulin_include))]
+    #[must_use]
+    fn display(&self, indent: usize) -> String {
+        let mut text = format!(
+            "{}{}@{}..{}\n",
+            "  ".repeat(indent),
+            self.kind,
+            self.span.bytes().start,
+            self.span.bytes().end
+        );
+
+        match &self.kind {
+            Expr::Atom(_) => {}
+            Expr::List(vec) | Expr::Map(vec) | Expr::Set(vec) | Expr::Vector(vec) => {
+                for node in vec {
+                    text.push_str(&format!("{}\n", node.display(indent + 1)));
+                }
+            }
+        }
+
+        text.trim_end().to_string()
+    }
+}
+
+impl TryFrom<Token> for Node {
+    type Error = ParserError;
+
+    fn try_from(token: Token) -> Result<Self, Self::Error> {
+        let span = token.span.clone();
+        let kind = Expr::try_from(token)?;
+
+        Ok(Self::new(kind, span))
+    }
+}
+
+#[cfg(not(tarpaulin_include))]
+impl std::fmt::Display for Node {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.display(0))
+    }
+}
+
 /// An atomic value.
 #[derive(Debug, Clone, PartialEq)]
-pub enum Atom {
+pub(crate) enum Atom {
     /// Boolean, e.g. `true`, `false`
     Bool(bool),
     /// Character, e.g. `'c'`, `'\n'`
@@ -45,7 +159,7 @@ impl std::fmt::Display for Atom {
 
 /// An expression.
 #[derive(Debug, Clone, PartialEq)]
-pub enum NodeKind {
+pub(crate) enum Expr {
     /// An atomic value.
     Atom(Atom),
     /// A list of nodes.
@@ -58,13 +172,25 @@ pub enum NodeKind {
     Vector(Vec<Node>),
 }
 
-impl From<Atom> for NodeKind {
+impl Expr {
+    /// Which closing delimiter is associated with the expression kind?
+    pub(crate) fn closing_delimiter(&self) -> Option<TokenKind> {
+        match self {
+            Expr::List(_) => Some(TokenKind::CloseParen),
+            Expr::Map(_) | Expr::Set(_) => Some(TokenKind::CloseBrace),
+            Expr::Vector(_) => Some(TokenKind::CloseBracket),
+            _ => None,
+        }
+    }
+}
+
+impl From<Atom> for Expr {
     fn from(atom: Atom) -> Self {
         Self::Atom(atom)
     }
 }
 
-impl TryFrom<Token> for NodeKind {
+impl TryFrom<Token> for Expr {
     type Error = ParserError;
 
     fn try_from(token: Token) -> Result<Self, Self::Error> {
@@ -78,10 +204,12 @@ impl TryFrom<Token> for NodeKind {
             TokenKind::Symbol(s) => Atom::Symbol(s),
             TokenKind::Nil => Atom::Nil,
             _ => {
-                return Err(ParserError::new(
+                // FIXME
-                    ParserErrorKind::UnexpectedState,
+                // return Err(ParserError::new(
-                    token.span,
+                //     ParserErrorKind::UnexpectedState,
-                ))
+                //     token.span,
+                // ))
+                todo!()
             }
         };
 
@@ -90,9 +218,9 @@ impl TryFrom<Token> for NodeKind {
 }
 
 #[cfg(not(tarpaulin_include))]
-impl std::fmt::Display for NodeKind {
+impl std::fmt::Display for Expr {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        use NodeKind::*;
+        use Expr::*;
 
         match self {
             Atom(atom) => write!(f, "{atom}"),
@@ -103,89 +231,3 @@ impl std::fmt::Display for NodeKind {
         }
     }
 }
-
-/// A node in the Abstract Syntax Tree (AST).
-///
-/// `Nodes`s contain the kind of node which was found, as well as a [Span]
-/// specifying the [Source] and [Location] of the node.
-///
-/// [Source]: crate::span::Source
-/// [Location]: crate::span::Location
-#[derive(Debug, Clone, PartialEq)]
-pub struct Node {
-    /// The kind of node.
-    pub kind: NodeKind,
-    /// The span in which the node occurs.
-    pub span: Span,
-}
-
-impl Node {
-    /// Construct a new instance of `Node`.
-    #[must_use]
-    pub const fn new(kind: NodeKind, span: Span) -> Self {
-        Self { kind, span }
-    }
-
-    /// Push a child node onto a list node.
-    pub fn push_node(&mut self, child: Self) -> Result<(), ParserError> {
-        match &mut self.kind {
-            NodeKind::List(vec)
-            | NodeKind::Map(vec)
-            | NodeKind::Set(vec)
-            | NodeKind::Vector(vec) => {
-                vec.push(child);
-            }
-            _ => {
-                return Err(ParserError::new(
-                    ParserErrorKind::UnexpectedState,
-                    child.span,
-                ))
-            }
-        }
-
-        Ok(())
-    }
-
-    #[cfg(not(tarpaulin_include))]
-    fn display(&self, indent: usize) -> String {
-        let mut text = format!(
-            "{}{}@{}..{}\n",
-            "  ".repeat(indent),
-            self.kind,
-            self.span.bytes().start,
-            self.span.bytes().end
-        );
-
-        match &self.kind {
-            NodeKind::Atom(_) => {}
-            NodeKind::List(vec)
-            | NodeKind::Map(vec)
-            | NodeKind::Set(vec)
-            | NodeKind::Vector(vec) => {
-                for node in vec {
-                    text.push_str(&format!("{}\n", node.display(indent + 1)));
-                }
-            }
-        }
-
-        text.trim_end().to_string()
-    }
-}
-
-impl TryFrom<Token> for Node {
-    type Error = ParserError;
-
-    fn try_from(token: Token) -> Result<Self, Self::Error> {
-        let span = token.span.clone();
-        let kind = NodeKind::try_from(token)?;
-
-        Ok(Self::new(kind, span))
-    }
-}
-
-#[cfg(not(tarpaulin_include))]
-impl std::fmt::Display for Node {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "{}", self.display(0))
-    }
-}

onihime/src/parser/error.rs

@@ -5,19 +5,16 @@ use crate::{lexer::LexerError, span::Span};
 pub enum ParserErrorKind {
     /// An error which ocurred during lexical analysis.
     Lexer(LexerError),
-    /// Expected a value for key in map, but no value was found.
+    /// Key in map is missing its corresponding value.
     MissingValueInMap,
-    /// An unexpecting closing parenthesis/brace/bracket was encountered.
+    /// Opening delimiter does not have a matching closing delimiter.
-    UnexpectedCloseBracket,
+    UnclosedSequence,
-    /// Unexpectedly reached the end of the input.
+    /// An unexpected closing delimiter was found.
+    UnexpectedClosingDelimiter,
+    /// Unexpectedly reached end of input.
     UnexpectedEof,
-    /// Unexpected parser state reached.
+    /// An unmatched closing delimiter was found.
-    UnexpectedState,
+    UnmatchedClosingDelimiter,
-    /// Opening parenthesis/brace/bracket does not have a matching closing
-    /// parenthesis/brace/bracket.
-    UnclosedBracket,
-    /// An unmatched parenthesis/brace/bracket was encountered.
-    UnmatchedBracket,
 }
 
 /// Parser error, with a start and end location.
@@ -30,13 +27,20 @@ pub struct ParserError {
 }
 
 impl ParserError {
-    /// Construct a new instance of `ParserErorr`.
+    /// Construct a new instance of `ParserError`.
     #[must_use]
     pub const fn new(kind: ParserErrorKind, span: Span) -> Self {
         Self { kind, span }
     }
 }
 
+impl From<LexerError> for ParserError {
+    fn from(err: LexerError) -> Self {
+        let span = err.span.clone();
+        Self::new(ParserErrorKind::Lexer(err), span)
+    }
+}
+
 impl std::error::Error for ParserError {}
 
 #[cfg(not(tarpaulin_include))]
@@ -46,19 +50,14 @@ impl std::fmt::Display for ParserError {
 
         match &self.kind {
             Lexer(err) => write!(f, "{err}"),
-            MissingValueInMap => write!(f, "Key in map is missing its value"),
+            MissingValueInMap => write!(f, "Key in map is missing its corresponding value"),
-            UnexpectedCloseBracket => write!(f, "Unexpected closing bracket"),
+            UnclosedSequence => write!(
-            UnexpectedEof => write!(f, "Unexpected reached end of input"),
+                f,
-            UnexpectedState => write!(f, "Unexpected parsing state reached"),
+                "Opening delimiter does not have a matching closing delimiter"
-            UnclosedBracket => write!(f, "Unclosed bracket"),
+            ),
-            UnmatchedBracket => write!(f, "Unmatched bracket"),
+            UnexpectedClosingDelimiter => write!(f, "An unexpected closing delimiter was found"),
+            UnexpectedEof => write!(f, "Unexpectedly reached end of input"),
+            UnmatchedClosingDelimiter => write!(f, "An unmatched closing delimiter was found"),
         }
     }
 }
-
-impl From<LexerError> for ParserError {
-    fn from(err: LexerError) -> Self {
-        let span = err.span.clone();
-        Self::new(ParserErrorKind::Lexer(err), span)
-    }
-}

onihime/src/parser/mod.rs

@@ -1,154 +1,154 @@
-pub use self::{
+use self::{
+    ast::{Ast, Expr, Node},
     error::{ParserError, ParserErrorKind},
-    node::{Node, NodeKind},
 };
-use crate::lexer::{Lexer, TokenKind};
+use crate::{
+    lexer::{Lexer, TokenKind},
+    span::Span,
+};
 
+mod ast;
 mod error;
-mod node;
 
-/// Parser for converting Onihime source code into an Abstract Syntax Tree
+pub(crate) struct Parser<'parser> {
-/// (AST).
-#[derive(Debug)]
-pub struct Parser<'parser> {
     lexer: Lexer<'parser>,
+    parents: Vec<Node>,
+    current: Node,
 }
 
 impl<'parser> Parser<'parser> {
     /// Create a new parser instance from a string.
     #[must_use]
-    pub fn new(input: &'parser str) -> Self {
+    pub(crate) fn new(input: &'parser str) -> Self {
+        let lexer = Lexer::new(input);
+        let current = Node::new(Expr::List(Vec::new()), lexer.span());
+
         Self {
-            lexer: Lexer::new(input),
+            lexer,
+            parents: Vec::new(),
+            current,
         }
     }
 
     /// Set the name of the lexer's source.
-    pub fn set_name(&mut self, name: String) {
+    pub(crate) fn set_name(&mut self, name: String) {
         self.lexer.set_name(name);
     }
 
-    /// Parse the input string into an AST.
+    /// Produce an Abstract Syntax Tree (AST) from the source input.
-    pub fn parse(&mut self) -> Result<Vec<Node>, ParserError> {
+    #[must_use]
-        let mut parents = Vec::new();
+    pub(crate) fn parse(mut self) -> Result<Ast, ParserError> {
-        let mut cur_node = Node::new(NodeKind::List(Vec::new()), self.lexer.span());
+        // This parser is actually quite simple!Recursively parse expressions until we
-
+        // run out of tokens, or an error occurs:
-        while let Some(token) = self.lexer.read()? {
+        while !self.lexer.eof() {
-            match token.kind {
+            if let Some(node) = self.expr()? {
-                TokenKind::BlockComment(_) | TokenKind::LineComment(_) => {}
+                self.current.push_node(node);
-
-                TokenKind::OpenParen => {
-                    let child = Node::new(NodeKind::List(Vec::new()), token.span);
-                    parents.push(cur_node);
-                    cur_node = child;
-                }
-                TokenKind::CloseParen => {
-                    let mut parent = parents.pop().ok_or_else(|| {
-                        ParserError::new(
-                            ParserErrorKind::UnexpectedCloseBracket,
-                            token.span.clone(),
-                        )
-                    })?;
-
-                    cur_node.span.extend(&token.span);
-
-                    if !matches!(cur_node.kind, NodeKind::List(_)) {
-                        return Err(ParserError::new(
-                            ParserErrorKind::UnmatchedBracket,
-                            token.span,
-                        ));
-                    }
-
-                    parent.push_node(cur_node)?;
-                    cur_node = parent;
-                }
-
-                TokenKind::OpenBrace => {
-                    let child = Node::new(NodeKind::Set(Vec::new()), token.span);
-                    parents.push(cur_node);
-                    cur_node = child;
-                }
-                TokenKind::OpenHashBrace => {
-                    let child = Node::new(NodeKind::Map(Vec::new()), token.span);
-                    parents.push(cur_node);
-                    cur_node = child;
-                }
-                TokenKind::CloseBrace => {
-                    let mut parent = parents.pop().ok_or_else(|| {
-                        ParserError::new(
-                            ParserErrorKind::UnexpectedCloseBracket,
-                            token.span.clone(),
-                        )
-                    })?;
-
-                    cur_node.span.extend(&token.span);
-
-                    if !matches!(cur_node.kind, NodeKind::Map(_) | NodeKind::Set(_)) {
-                        return Err(ParserError::new(
-                            ParserErrorKind::UnmatchedBracket,
-                            token.span,
-                        ));
-                    }
-
-                    if let NodeKind::Map(ref vec) = cur_node.kind {
-                        if vec.len() % 2 != 0 {
-                            return Err(ParserError::new(
-                                ParserErrorKind::MissingValueInMap,
-                                token.span,
-                            ));
-                        }
-                    }
-
-                    parent.push_node(cur_node)?;
-                    cur_node = parent;
-                }
-
-                TokenKind::OpenBracket => {
-                    let child = Node::new(NodeKind::Vector(Vec::new()), token.span);
-                    parents.push(cur_node);
-                    cur_node = child;
-                }
-                TokenKind::CloseBracket => {
-                    let mut parent = parents.pop().ok_or_else(|| {
-                        ParserError::new(
-                            ParserErrorKind::UnexpectedCloseBracket,
-                            token.span.clone(),
-                        )
-                    })?;
-
-                    cur_node.span.extend(&token.span);
-
-                    if !matches!(cur_node.kind, NodeKind::Vector(_)) {
-                        return Err(ParserError::new(
-                            ParserErrorKind::UnmatchedBracket,
-                            token.span,
-                        ));
-                    }
-
-                    parent.push_node(cur_node)?;
-                    cur_node = parent;
-                }
-
-                _ => {
-                    let node = Node::try_from(token)?;
-                    cur_node.push_node(node)?;
-                }
             }
         }
 
-        if !parents.is_empty() {
+        // When we reach the end of input, there should be no remaining parent nodes; if
+        // there are, that means that there is a missing closing delimiter somewhere:
+        if !self.parents.is_empty() {
             return Err(ParserError::new(
-                ParserErrorKind::UnclosedBracket,
+                ParserErrorKind::UnclosedSequence,
-                cur_node.span,
+                self.current.span,
             ));
         }
 
-        if let NodeKind::List(body) = cur_node.kind {
+        // Since we created an initial `Expr::List` node to hold the parsed contents
-            Ok(body)
+        // (i.e. so that we had something to push nodes to), we can now rip out its guts
+        // and return the newly constructed AST:
+        if let Expr::List(root) = self.current.kind {
+            Ok(Ast::new(root))
         } else {
-            unreachable!() // In theory, at least...
+            unreachable!() // TODO: Is this really true? It should be... right?
         }
     }
+
+    #[must_use]
+    fn expr(&mut self) -> Result<Option<Node>, ParserError> {
+        if let Some(token) = self.lexer.read()? {
+            match token.kind {
+                // Comments are simply ignored by the parser:
+                TokenKind::BlockComment(_) | TokenKind::LineComment(_) => Ok(None),
+
+                // Any valid opening delimiters begins a new sequence:
+                TokenKind::OpenParen => self.begin_sequence(Expr::List, token.span),
+                TokenKind::OpenHashBrace => self.begin_sequence(Expr::Map, token.span),
+                TokenKind::OpenBrace => self.begin_sequence(Expr::Set, token.span),
+                TokenKind::OpenBracket => self.begin_sequence(Expr::Vector, token.span),
+
+                // Any valid closing delimiters end the current sequence:
+                kind
+                @ (TokenKind::CloseParen | TokenKind::CloseBrace | TokenKind::CloseBracket) => {
+                    self.end_sequence(kind, token.span)
+                }
+
+                // Atoms are pushed to the current sequence:
+                _ => {
+                    let node = Node::try_from(token)?;
+                    let span = node.span.clone();
+
+                    self.current.push_node(node);
+                    self.current.span.extend(&span);
+
+                    Ok(None)
+                }
+            }
+        } else {
+            Err(ParserError::new(
+                ParserErrorKind::UnexpectedEof,
+                self.lexer.span(),
+            ))
+        }
+    }
+
+    #[must_use]
+    fn begin_sequence(
+        &mut self,
+        init: impl FnOnce(Vec<Node>) -> Expr,
+        span: Span,
+    ) -> Result<Option<Node>, ParserError> {
+        self.current.span.extend(&span);
+        self.parents.push(self.current.clone());
+
+        self.current = Node::new(init(Vec::new()), span.clone());
+
+        Ok(None)
+    }
+
+    #[must_use]
+    fn end_sequence(&mut self, kind: TokenKind, span: Span) -> Result<Option<Node>, ParserError> {
+        // We will ultimately return the current expression, so clone it and update its
+        // span first:
+        let mut current = self.current.clone();
+        current.span.extend(&span);
+
+        // Update the parser's current node to the previous parent, or return an error
+        // if no parents exist:
+        self.current = self.parents.pop().ok_or_else(|| {
+            ParserError::new(ParserErrorKind::UnexpectedClosingDelimiter, span.clone())
+        })?;
+
+        // Ensure that the appropriate closing delimiter was found for our current node:
+        if current.kind.closing_delimiter() != Some(kind) {
+            return Err(ParserError::new(
+                ParserErrorKind::UnmatchedClosingDelimiter,
+                span,
+            ));
+        }
+
+        // For maps, ensure that each key has a corresponding value:
+        match current.kind {
+            Expr::Map(ref vec) if vec.len() % 2 != 0 => {
+                return Err(ParserError::new(ParserErrorKind::MissingValueInMap, span));
+            }
+            _ => {}
+        }
+
+        // Finally, return the current node so it can be added to the AST:
+        Ok(Some(current))
+    }
 }
 
 #[cfg(test)]
@@ -156,8 +156,7 @@ mod tests {
     use super::*;
     use crate::{
         lexer::{LexerError, LexerErrorKind, Symbol},
-        parser::node::Atom,
+        parser::ast::Atom,
-        span::Span,
     };
 
     macro_rules! test {
@@ -171,7 +170,7 @@ mod tests {
         };
     }
 
-    test!(empty: "", _src => Ok(vec![]));
+    test!(empty: "", _src => Ok(Ast::default()));
 
     test!(error_invalid_number: "(+ 1.2.3)", src => Err(ParserError::new(
         ParserErrorKind::Lexer(LexerError::new(
@@ -181,35 +180,35 @@ mod tests {
         Span::new(3..8, src)
     )));
 
-    test!(list: "(+ 1 2) ; sneaky comment :)", src => Ok(vec![
+    test!(list: "(+ 1 2) ; sneaky comment :)", src => Ok(Ast::from(vec![
         Node::new(
-            NodeKind::List(vec![
+            Expr::List(vec![
                 Node::new(Atom::Symbol(Symbol::from("+")).into(), Span::new(1..2, src.clone())),
                 Node::new(Atom::Integer(1).into(), Span::new(3..4, src.clone())),
                 Node::new(Atom::Integer(2).into(), Span::new(5..6, src.clone())),
             ]),
             Span::new(0..7, src)
         )
-    ]));
+    ])));
 
     test!(error_list_unmatched_bracket: "(]", src => Err(ParserError::new(
-        ParserErrorKind::UnmatchedBracket,
+        ParserErrorKind::UnmatchedClosingDelimiter,
         Span::new(1..2, src),
     )));
 
     test!(error_list_missing_close_paren: "(true", src => Err(ParserError::new(
-        ParserErrorKind::UnclosedBracket,
+        ParserErrorKind::UnclosedSequence,
-        Span::new(0..1, src),
+        Span::new(0..5, src),
     )));
 
     test!(error_list_unexpected_close_paren: ")", src => Err(ParserError::new(
-        ParserErrorKind::UnexpectedCloseBracket,
+        ParserErrorKind::UnexpectedClosingDelimiter,
         Span::new(0..1, src)
     )));
 
-    test!(map: "#{:a 0.0 :b 1.0}", src => Ok(vec![
+    test!(map: "#{:a 0.0 :b 1.0}", src => Ok(Ast::from(vec![
         Node::new(
-            NodeKind::Map(vec![
+            Expr::Map(vec![
                 Node::new(Atom::Keyword(Symbol::from("a")).into(), Span::new(2..4, src.clone())),
                 Node::new(Atom::Float(0.0).into(), Span::new(5..8, src.clone())),
                 Node::new(Atom::Keyword(Symbol::from("b")).into(), Span::new(9..11, src.clone())),
@@ -217,7 +216,7 @@ mod tests {
             ]),
             Span::new(0..16, src)
         )
-    ]));
+    ])));
 
     test!(error_map_missing_value: "#{:x}", src => Err(ParserError::new(
         ParserErrorKind::MissingValueInMap,
@@ -225,74 +224,74 @@ mod tests {
     )));
 
     test!(error_map_unmatched_bracket: "#{)", src => Err(ParserError::new(
-        ParserErrorKind::UnmatchedBracket,
+        ParserErrorKind::UnmatchedClosingDelimiter,
         Span::new(2..3, src),
     )));
 
     test!(error_map_missing_close_brace: "#{", src => Err(ParserError::new(
-        ParserErrorKind::UnclosedBracket,
+        ParserErrorKind::UnclosedSequence,
         Span::new(0..2, src),
     )));
 
-    test!(set: "{{} nil}", src => Ok(vec![
+    test!(error_map_set_unexpected_close_brace: "}", src => Err(ParserError::new(
+        ParserErrorKind::UnexpectedClosingDelimiter,
+        Span::new(0..1, src)
+    )));
+
+    test!(set: "{{} nil}", src => Ok(Ast::from(vec![
         Node::new(
-            NodeKind::Set(vec![
+            Expr::Set(vec![
-                Node::new(NodeKind::Set(vec![]), Span::new(1..3, src.clone())),
+                Node::new(Expr::Set(vec![]), Span::new(1..3, src.clone())),
-                Node::new(NodeKind::Atom(Atom::Nil), Span::new(4..7, src.clone())),
+                Node::new(Expr::Atom(Atom::Nil), Span::new(4..7, src.clone())),
             ]),
             Span::new(0..8, src),
         )
-    ]));
+    ])));
 
     test!(error_set_unmatched_bracket: "{]", src => Err(ParserError::new(
-        ParserErrorKind::UnmatchedBracket,
+        ParserErrorKind::UnmatchedClosingDelimiter,
         Span::new(1..2, src),
     )));
 
     test!(error_set_missing_close_brace: "{", src => Err(ParserError::new(
-        ParserErrorKind::UnclosedBracket,
+        ParserErrorKind::UnclosedSequence,
         Span::new(0..1, src),
     )));
 
-    test!(error_map_set_unexpected_close_brace: "}", src => Err(ParserError::new(
+    test!(vector: "['a' 'b' 'c']", src => Ok(Ast::from(vec![
-        ParserErrorKind::UnexpectedCloseBracket,
-        Span::new(0..1, src)
-    )));
-
-    test!(vector: "['a' 'b' 'c']", src => Ok(vec![
         Node::new(
-            NodeKind::Vector(vec![
+            Expr::Vector(vec![
-                Node::new(NodeKind::Atom(Atom::Char('a')), Span::new(1..4, src.clone())),
+                Node::new(Expr::Atom(Atom::Char('a')), Span::new(1..4, src.clone())),
-                Node::new(NodeKind::Atom(Atom::Char('b')), Span::new(5..8, src.clone())),
+                Node::new(Expr::Atom(Atom::Char('b')), Span::new(5..8, src.clone())),
-                Node::new(NodeKind::Atom(Atom::Char('c')), Span::new(9..12, src.clone())),
+                Node::new(Expr::Atom(Atom::Char('c')), Span::new(9..12, src.clone())),
             ]),
             Span::new(0..13, src),
         )
-    ]));
+    ])));
 
     test!(error_vector_unmatched_bracket: "[}", src => Err(ParserError::new(
-        ParserErrorKind::UnmatchedBracket,
+        ParserErrorKind::UnmatchedClosingDelimiter,
         Span::new(1..2, src),
     )));
 
-    test!(error_vector_missing_close_bracket: "{", src => Err(ParserError::new(
+    test!(error_vector_missing_close_bracket: "[", src => Err(ParserError::new(
-        ParserErrorKind::UnclosedBracket,
+        ParserErrorKind::UnclosedSequence,
         Span::new(0..1, src),
     )));
 
     test!(error_vector_unexpected_close_bracket: "]", src => Err(ParserError::new(
-        ParserErrorKind::UnexpectedCloseBracket,
+        ParserErrorKind::UnexpectedClosingDelimiter,
         Span::new(0..1, src)
     )));
 
-    test!(multiple_expressions: "(/ 6 3 (+ 1 2)) (* 2 5)\n(- 10 5)", src => Ok(vec![
+    test!(multiple_expressions: "(/ 6 3 (+ 1 2)) (* 2 5)\n(- 10 5)", src => Ok(Ast::from(vec![
         Node::new(
-            NodeKind::List(vec![
+            Expr::List(vec![
                 Node::new(Atom::Symbol(Symbol::from("/")).into(), Span::new(1..2, src.clone())),
                 Node::new(Atom::Integer(6).into(), Span::new(3..4, src.clone())),
                 Node::new(Atom::Integer(3).into(), Span::new(5..6, src.clone())),
                 Node::new(
-                    NodeKind::List(vec![
+                    Expr::List(vec![
                         Node::new(Atom::Symbol(Symbol::from("+")).into(), Span::new(8..9, src.clone())),
                         Node::new(Atom::Integer(1).into(), Span::new(10..11, src.clone())),
                         Node::new(Atom::Integer(2).into(), Span::new(12..13, src.clone())),
@@ -303,7 +302,7 @@ mod tests {
             Span::new(0..15, src.clone())
         ),
         Node::new(
-            NodeKind::List(vec![
+            Expr::List(vec![
                 Node::new(Atom::Symbol(Symbol::from("*")).into(), Span::new(17..18, src.clone())),
                 Node::new(Atom::Integer(2).into(), Span::new(19..20, src.clone())),
                 Node::new(Atom::Integer(5).into(), Span::new(21..22, src.clone())),
@@ -311,21 +310,21 @@ mod tests {
             Span::new(16..23, src.clone())
         ),
         Node::new(
-            NodeKind::List(vec![
+            Expr::List(vec![
                 Node::new(Atom::Symbol(Symbol::from("-")).into(), Span::new(25..26, src.clone())),
                 Node::new(Atom::Integer(10).into(), Span::new(27..29, src.clone())),
                 Node::new(Atom::Integer(5).into(), Span::new(30..31, src.clone())),
             ]),
             Span::new(24..32, src)
         ),
-    ]));
+    ])));
 
-    test!(function_application: "(join \"foo\" \"bar\")", src => Ok(vec![Node::new(
+    test!(function_application: "(join \"foo\" \"bar\")", src => Ok(Ast::from(vec![Node::new(
-        NodeKind::List(vec![
+        Expr::List(vec![
             Node::new(Atom::Symbol(Symbol::from("join")).into(), Span::new(1..5, src.clone())),
             Node::new(Atom::String("foo".into()).into(), Span::new(6..11, src.clone())),
             Node::new(Atom::String("bar".into()).into(), Span::new(12..17, src.clone())),
         ]),
         Span::new(0..18, src)
-    )]));
+    )])));
 }