Code Review: Life is Like a Box of Iterators

9 files changed, 150 insertions, 142 deletions

diff --git a/benches/oneshot.rs b/benches/oneshot.rs
index a42a710d..63f201ac 100644
--- a/benches/oneshot.rs
+++ b/benches/oneshot.rs
@@ -6,7 +6,7 @@ use typst::eval::eval;
 use typst::layout::layout;
 use typst::loading::MemLoader;
 use typst::parse::{parse, Scanner, TokenMode, Tokens};
-use typst::source::{SourceFile, SourceId};
+use typst::source::SourceId;
 use typst::Context;
 
 const SRC: &str = include_str!("bench.typ");
@@ -44,13 +44,11 @@ fn bench_scan(iai: &mut Iai) {
 }
 
 fn bench_tokenize(iai: &mut Iai) {
-    let src = SourceFile::detached(SRC);
-    iai.run(|| Tokens::new(black_box(&src), black_box(TokenMode::Markup)).count());
+    iai.run(|| Tokens::new(black_box(&SRC), black_box(TokenMode::Markup)).count());
 }
 
 fn bench_parse(iai: &mut Iai) {
-    let src = SourceFile::detached(SRC);
-    iai.run(|| parse(&src));
+    iai.run(|| parse(&SRC));
 }
 
 fn bench_eval(iai: &mut Iai) {
diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index 22288d01..c6def4dc 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -12,12 +12,11 @@ pub use tokens::*;
 
 use std::rc::Rc;
 
-use crate::source::SourceFile;
 use crate::syntax::*;
 use crate::util::EcoString;
 
 /// Parse a source file.
-pub fn parse(source: &SourceFile) -> Rc<GreenNode> {
+pub fn parse(source: &str) -> Rc<GreenNode> {
     let mut p = Parser::new(source);
     markup(&mut p);
     p.finish()
diff --git a/src/parse/parser.rs b/src/parse/parser.rs
index 240de43d..374e7c09 100644
--- a/src/parse/parser.rs
+++ b/src/parse/parser.rs
@@ -1,15 +1,14 @@
 use std::ops::Range;
 use std::rc::Rc;
 
-use super::{TokenMode, Tokens};
-use crate::source::{SourceFile, SourceId};
+use super::{is_newline, TokenMode, Tokens};
 use crate::syntax::{ErrorPosition, Green, GreenData, GreenNode, NodeKind};
 use crate::util::EcoString;
 
 /// A convenient token-based parser.
 pub struct Parser<'s> {
     /// The parsed file.
-    source: &'s SourceFile,
+    src: &'s str,
     /// An iterator over the source tokens.
     tokens: Tokens<'s>,
     /// The stack of open groups.
@@ -61,11 +60,11 @@ pub enum Group {
 
 impl<'s> Parser<'s> {
     /// Create a new parser for the source string.
-    pub fn new(source: &'s SourceFile) -> Self {
-        let mut tokens = Tokens::new(source, TokenMode::Markup);
+    pub fn new(src: &'s str) -> Self {
+        let mut tokens = Tokens::new(src, TokenMode::Markup);
         let next = tokens.next();
         Self {
-            source,
+            src,
             tokens,
             groups: vec![],
             next: next.clone(),
@@ -78,11 +77,6 @@ impl<'s> Parser<'s> {
         }
     }
 
-    /// The id of the parsed source file.
-    pub fn id(&self) -> SourceId {
-        self.source.id()
-    }
-
     /// Start a nested node.
     ///
     /// Each start call has to be matched with a call to `end`,
@@ -366,12 +360,16 @@ impl<'s> Parser<'s> {
 
     /// Determine the column index for the given byte index.
     pub fn column(&self, index: usize) -> usize {
-        self.source.byte_to_column(index).unwrap()
+        self.src[.. index]
+            .chars()
+            .rev()
+            .take_while(|&c| !is_newline(c))
+            .count()
     }
 
     /// Slice out part of the source string.
     pub fn get(&self, range: Range<usize>) -> &'s str {
-        self.source.get(range).unwrap()
+        self.src.get(range).unwrap()
     }
 
     /// Continue parsing in a group.
diff --git a/src/parse/resolve.rs b/src/parse/resolve.rs
index 8d4c04d4..3fab98a4 100644
--- a/src/parse/resolve.rs
+++ b/src/parse/resolve.rs
@@ -1,5 +1,5 @@
 use super::{is_newline, Scanner};
-use crate::syntax::RawToken;
+use crate::syntax::RawData;
 use crate::util::EcoString;
 
 /// Resolve all escape sequences in a string.
@@ -46,18 +46,18 @@ pub fn resolve_hex(sequence: &str) -> Option<char> {
 }
 
 /// Resolve the language tag and trims the raw text.
-pub fn resolve_raw(column: usize, backticks: u8, text: &str) -> RawToken {
+pub fn resolve_raw(column: usize, backticks: u8, text: &str) -> RawData {
     if backticks > 1 {
         let (tag, inner) = split_at_lang_tag(text);
         let (text, block) = trim_and_split_raw(column, inner);
-        RawToken {
+        RawData {
             lang: Some(tag.into()),
             text: text.into(),
             backticks,
             block,
         }
     } else {
-        RawToken {
+        RawData {
             lang: None,
             text: split_lines(text).join("\n").into(),
             backticks,
diff --git a/src/parse/scanner.rs b/src/parse/scanner.rs
index 8e3e4278..edf28e17 100644
--- a/src/parse/scanner.rs
+++ b/src/parse/scanner.rs
@@ -106,6 +106,16 @@ impl<'s> Scanner<'s> {
         self.index
     }
 
+    /// The column index of a given index in the source string.
+    #[inline]
+    pub fn column(&self, index: usize) -> usize {
+        self.src[.. index]
+            .chars()
+            .rev()
+            .take_while(|&c| !is_newline(c))
+            .count()
+    }
+
     /// Jump to an index in the source string.
     #[inline]
     pub fn jump(&mut self, index: usize) {
diff --git a/src/parse/tokens.rs b/src/parse/tokens.rs
index 1d2e32ec..ef2678d4 100644
--- a/src/parse/tokens.rs
+++ b/src/parse/tokens.rs
@@ -1,7 +1,6 @@
 use super::{is_newline, resolve_raw, Scanner};
 use crate::geom::{AngularUnit, LengthUnit};
 use crate::parse::resolve::{resolve_hex, resolve_string};
-use crate::source::SourceFile;
 use crate::syntax::*;
 use crate::util::EcoString;
 
@@ -9,7 +8,6 @@ use std::rc::Rc;
 
 /// An iterator over the tokens of a string of source code.
 pub struct Tokens<'s> {
-    source: &'s SourceFile,
     s: Scanner<'s>,
     mode: TokenMode,
 }
@@ -26,12 +24,8 @@ pub enum TokenMode {
 impl<'s> Tokens<'s> {
     /// Create a new token iterator with the given mode.
     #[inline]
-    pub fn new(source: &'s SourceFile, mode: TokenMode) -> Self {
-        Self {
-            s: Scanner::new(source.src()),
-            source,
-            mode,
-        }
+    pub fn new(source: &'s str, mode: TokenMode) -> Self {
+        Self { s: Scanner::new(source), mode }
     }
 
     /// Get the current token mode.
@@ -244,7 +238,7 @@ impl<'s> Tokens<'s> {
 
                     if self.s.eat_if('}') {
                         if let Some(character) = resolve_hex(&sequence) {
-                            NodeKind::UnicodeEscape(UnicodeEscapeToken {
+                            NodeKind::UnicodeEscape(UnicodeEscapeData {
                                 character,
                             })
                         } else {
@@ -314,7 +308,7 @@ impl<'s> Tokens<'s> {
     }
 
     fn raw(&mut self) -> NodeKind {
-        let column = self.source.byte_to_column(self.s.index() - 1).unwrap();
+        let column = self.s.column(self.s.index() - 1);
         let mut backticks = 1;
         while self.s.eat_if('`') && backticks < u8::MAX {
             backticks += 1;
@@ -322,7 +316,7 @@ impl<'s> Tokens<'s> {
 
         // Special case for empty inline block.
         if backticks == 2 {
-            return NodeKind::Raw(Rc::new(RawToken {
+            return NodeKind::Raw(Rc::new(RawData {
                 text: EcoString::new(),
                 lang: None,
                 backticks: 1,
@@ -397,7 +391,7 @@ impl<'s> Tokens<'s> {
             };
 
         if terminated {
-            NodeKind::Math(Rc::new(MathToken {
+            NodeKind::Math(Rc::new(MathData {
                 formula: self.s.get(start .. end).into(),
                 display,
             }))
@@ -492,7 +486,7 @@ impl<'s> Tokens<'s> {
             }
         }));
         if self.s.eat_if('"') {
-            NodeKind::Str(StrToken { string })
+            NodeKind::Str(StrData { string })
         } else {
             NodeKind::Error(ErrorPosition::End, "expected quote".into())
         }
@@ -567,7 +561,7 @@ mod tests {
     use TokenMode::{Code, Markup};
 
     fn UnicodeEscape(character: char) -> NodeKind {
-        NodeKind::UnicodeEscape(UnicodeEscapeToken { character })
+        NodeKind::UnicodeEscape(UnicodeEscapeData { character })
     }
 
     fn Error(pos: ErrorPosition, message: &str) -> NodeKind {
@@ -575,7 +569,7 @@ mod tests {
     }
 
     fn Raw(text: &str, lang: Option<&str>, backticks_left: u8, block: bool) -> NodeKind {
-        NodeKind::Raw(Rc::new(RawToken {
+        NodeKind::Raw(Rc::new(RawData {
             text: text.into(),
             lang: lang.map(Into::into),
             backticks: backticks_left,
@@ -586,7 +580,7 @@ mod tests {
     fn Math(formula: &str, display: bool, err_msg: Option<&str>) -> NodeKind {
         match err_msg {
             None => {
-                NodeKind::Math(Rc::new(MathToken { formula: formula.into(), display }))
+                NodeKind::Math(Rc::new(MathData { formula: formula.into(), display }))
             }
             Some(msg) => NodeKind::Error(
                 ErrorPosition::End,
@@ -597,7 +591,7 @@ mod tests {
 
     fn Str(string: &str, terminated: bool) -> NodeKind {
         if terminated {
-            NodeKind::Str(StrToken { string: string.into() })
+            NodeKind::Str(StrData { string: string.into() })
         } else {
             NodeKind::Error(ErrorPosition::End, "expected quote".into())
         }
@@ -687,7 +681,7 @@ mod tests {
         }};
         (@$mode:ident: $src:expr => $($token:expr),*) => {{
             let src = $src;
-            let found = Tokens::new(&SourceFile::detached(src.clone()), $mode).collect::<Vec<_>>();
+            let found = Tokens::new(&src, $mode).collect::<Vec<_>>();
             let expected = vec![$($token.clone()),*];
             check(&src, found, expected);
         }};
diff --git a/src/source.rs b/src/source.rs
index e3803f57..3b721251 100644
--- a/src/source.rs
+++ b/src/source.rs
@@ -8,10 +8,10 @@ use std::rc::Rc;
 
 use serde::{Deserialize, Serialize};
 
-use crate::diag::{Error, TypResult};
+use crate::diag::TypResult;
 use crate::loading::{FileHash, Loader};
 use crate::parse::{is_newline, parse, Scanner};
-use crate::syntax::{GreenNode, Markup, NodeKind, RedNode};
+use crate::syntax::{GreenNode, Markup, RedNode};
 use crate::util::PathExt;
 
 #[cfg(feature = "codespan-reporting")]
@@ -134,28 +134,22 @@ impl SourceFile {
     pub fn new(id: SourceId, path: &Path, src: String) -> Self {
         let mut line_starts = vec![0];
         line_starts.extend(newlines(&src));
-        let mut init = Self {
+        Self {
             id,
             path: path.normalize(),
+            root: parse(&src),
             src,
             line_starts,
-            root: Rc::new(GreenNode::new(NodeKind::Markup, 0)),
-        };
-
-        let root = parse(&init);
-        init.root = root;
-        init
+        }
     }
 
     pub fn ast(&self) -> TypResult<Markup> {
         let red = RedNode::new_root(self.root.clone(), self.id);
         let errors = red.errors();
         if errors.is_empty() {
-            Ok(red.as_ref().cast().unwrap())
+            Ok(red.cast().unwrap())
         } else {
-            Err(Box::new(
-                errors.into_iter().map(|(span, msg)| Error::new(span, msg)).collect(),
-            ))
+            Err(Box::new(errors))
         }
     }
 
diff --git a/src/syntax/ast.rs b/src/syntax/ast.rs
index bdd0767d..6ca271a9 100644
--- a/src/syntax/ast.rs
+++ b/src/syntax/ast.rs
@@ -1,8 +1,39 @@
 use super::{Ident, NodeKind, RedNode, RedRef, Span, TypedNode};
 use crate::geom::{AngularUnit, LengthUnit};
-use crate::node;
 use crate::util::EcoString;
 
+macro_rules! node {
+    ($(#[$attr:meta])* $name:ident) => {
+        node!{$(#[$attr])* $name => $name}
+    };
+    ($(#[$attr:meta])* $variant:ident => $name:ident) => {
+        #[derive(Debug, Clone, PartialEq)]
+        #[repr(transparent)]
+        $(#[$attr])*
+        pub struct $name(RedNode);
+
+        impl TypedNode for $name {
+            fn cast_from(node: RedRef) -> Option<Self> {
+                if node.kind() != &NodeKind::$variant {
+                    return None;
+                }
+
+                Some(Self(node.own()))
+            }
+        }
+
+        impl $name {
+            pub fn span(&self) -> Span {
+                self.0.span()
+            }
+
+            pub fn underlying(&self) -> RedRef {
+                self.0.as_ref()
+            }
+        }
+    };
+}
+
 node! {
     /// The syntactical root capable of representing a full parsed document.
     Markup
diff --git a/src/syntax/mod.rs b/src/syntax/mod.rs
index 9fd2b21d..ca41d33f 100644
--- a/src/syntax/mod.rs
+++ b/src/syntax/mod.rs
@@ -15,6 +15,7 @@ pub use ident::*;
 pub use pretty::*;
 pub use span::*;
 
+use crate::diag::Error;
 use crate::geom::{AngularUnit, LengthUnit};
 use crate::source::SourceId;
 use crate::util::EcoString;
@@ -94,9 +95,9 @@ impl GreenNode {
     }
 
     pub fn with_children(kind: NodeKind, len: usize, children: Vec<Green>) -> Self {
-        let mut meta = GreenData::new(kind, len);
-        meta.erroneous |= children.iter().any(|c| c.erroneous());
-        Self { data: meta, children }
+        let mut data = GreenData::new(kind, len);
+        data.erroneous |= children.iter().any(|c| c.erroneous());
+        Self { data, children }
     }
 
     pub fn with_child(kind: NodeKind, len: usize, child: impl Into<Green>) -> Self {
@@ -180,6 +181,10 @@ impl<'a> RedRef<'a> {
         Span::new(self.id, self.offset, self.offset + self.green.len())
     }
 
+    pub fn len(&self) -> usize {
+        self.green.len()
+    }
+
     pub fn cast<T>(self) -> Option<T>
     where
         T: TypedNode,
@@ -205,6 +210,29 @@ impl<'a> RedRef<'a> {
         })
     }
 
+    pub fn errors(&self) -> Vec<Error> {
+        if !self.green.erroneous() {
+            return vec![];
+        }
+
+        match self.kind() {
+            NodeKind::Error(pos, msg) => {
+                let span = match pos {
+                    ErrorPosition::Start => self.span().at_start(),
+                    ErrorPosition::Full => self.span(),
+                    ErrorPosition::End => self.span().at_end(),
+                };
+
+                vec![Error::new(span, msg.to_string())]
+            }
+            _ => self
+                .children()
+                .filter(|red| red.green.erroneous())
+                .flat_map(|red| red.errors())
+                .collect(),
+        }
+    }
+
     pub(crate) fn typed_child(&self, kind: &NodeKind) -> Option<RedRef> {
         self.children()
             .find(|x| mem::discriminant(x.kind()) == mem::discriminant(kind))
@@ -219,6 +247,18 @@ impl<'a> RedRef<'a> {
     }
 }
 
+impl Debug for RedRef<'_> {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{:?}: {:?}", self.kind(), self.span())?;
+        let mut children = self.children().peekable();
+        if children.peek().is_some() {
+            f.write_str(" ")?;
+            f.debug_list().entries(children.map(RedRef::own)).finish()?;
+        }
+        Ok(())
+    }
+}
+
 #[derive(Clone, PartialEq)]
 pub struct RedNode {
     id: SourceId,
@@ -231,12 +271,27 @@ impl RedNode {
         Self { id, offset: 0, green: root.into() }
     }
 
+    pub fn as_ref<'a>(&'a self) -> RedRef<'a> {
+        RedRef {
+            id: self.id,
+            offset: self.offset,
+            green: &self.green,
+        }
+    }
+
     pub fn span(&self) -> Span {
         self.as_ref().span()
     }
 
     pub fn len(&self) -> usize {
-        self.green.len()
+        self.as_ref().len()
+    }
+
+    pub fn cast<T>(self) -> Option<T>
+    where
+        T: TypedNode,
+    {
+        T::cast_from(self.as_ref())
     }
 
     pub fn kind(&self) -> &NodeKind {
@@ -247,36 +302,8 @@ impl RedNode {
         self.as_ref().children()
     }
 
-    pub fn errors(&self) -> Vec<(Span, EcoString)> {
-        if !self.green.erroneous() {
-            return vec![];
-        }
-
-        match self.kind() {
-            NodeKind::Error(pos, msg) => {
-                let span = match pos {
-                    ErrorPosition::Start => self.span().at_start(),
-                    ErrorPosition::Full => self.span(),
-                    ErrorPosition::End => self.span().at_end(),
-                };
-
-                vec![(span, msg.clone())]
-            }
-            _ => self
-                .as_ref()
-                .children()
-                .filter(|red| red.green.erroneous())
-                .flat_map(|red| red.own().errors())
-                .collect(),
-        }
-    }
-
-    pub fn as_ref<'a>(&'a self) -> RedRef<'a> {
-        RedRef {
-            id: self.id,
-            offset: self.offset,
-            green: &self.green,
-        }
+    pub fn errors<'a>(&'a self) -> Vec<Error> {
+        self.as_ref().errors()
     }
 
     pub(crate) fn typed_child(&self, kind: &NodeKind) -> Option<RedNode> {
@@ -294,15 +321,7 @@ impl RedNode {
 
 impl Debug for RedNode {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{:?}: {:?}", self.kind(), self.span())?;
-        let children = self.as_ref().children().collect::<Vec<_>>();
-        if !children.is_empty() {
-            f.write_str(" ")?;
-            f.debug_list()
-                .entries(children.into_iter().map(RedRef::own))
-                .finish()?;
-        }
-        Ok(())
+        self.as_ref().fmt(f)
     }
 }
 
@@ -419,7 +438,7 @@ pub enum NodeKind {
     EmDash,
     /// A slash and the letter "u" followed by a hexadecimal unicode entity
     /// enclosed in curly braces: `\u{1F5FA}`.
-    UnicodeEscape(UnicodeEscapeToken),
+    UnicodeEscape(UnicodeEscapeData),
     /// Strong text was enabled / disabled: `*`.
     Strong,
     /// Emphasized text was enabled / disabled: `_`.
@@ -440,9 +459,9 @@ pub enum NodeKind {
     ListBullet,
     /// An arbitrary number of backticks followed by inner contents, terminated
     /// with the same number of backticks: `` `...` ``.
-    Raw(Rc<RawToken>),
+    Raw(Rc<RawData>),
     /// Dollar signs surrounding inner contents.
-    Math(Rc<MathToken>),
+    Math(Rc<MathData>),
     /// An identifier: `center`.
     Ident(EcoString),
     /// A boolean: `true`, `false`.
@@ -463,7 +482,7 @@ pub enum NodeKind {
     /// A fraction unit: `3fr`.
     Fraction(f64),
     /// A quoted string: `"..."`.
-    Str(StrToken),
+    Str(StrData),
     /// An array expression: `(1, "hi", 12cm)`.
     Array,
     /// A dictionary expression: `(thickness: 3pt, pattern: dashed)`.
@@ -534,15 +553,14 @@ pub enum ErrorPosition {
 
 /// A quoted string token: `"..."`.
 #[derive(Debug, Clone, PartialEq)]
-#[repr(transparent)]
-pub struct StrToken {
+pub struct StrData {
     /// The string inside the quotes.
     pub string: EcoString,
 }
 
 /// A raw block token: `` `...` ``.
 #[derive(Debug, Clone, PartialEq)]
-pub struct RawToken {
+pub struct RawData {
     /// The raw text in the block.
     pub text: EcoString,
     /// The programming language of the raw text.
@@ -555,7 +573,7 @@ pub struct RawToken {
 
 /// A math formula token: `$2pi + x$` or `$[f'(x) = x^2]$`.
 #[derive(Debug, Clone, PartialEq)]
-pub struct MathToken {
+pub struct MathData {
     /// The formula between the dollars.
     pub formula: EcoString,
     /// Whether the formula is display-level, that is, it is surrounded by
@@ -565,8 +583,7 @@ pub struct MathToken {
 
 /// A unicode escape sequence token: `\u{1F5FA}`.
 #[derive(Debug, Clone, PartialEq)]
-#[repr(transparent)]
-pub struct UnicodeEscapeToken {
+pub struct UnicodeEscapeData {
     /// The resulting unicode character.
     pub character: char,
 }
@@ -712,36 +729,3 @@ impl NodeKind {
         }
     }
 }
-
-#[macro_export]
-macro_rules! node {
-    ($(#[$attr:meta])* $name:ident) => {
-        node!{$(#[$attr])* $name => $name}
-    };
-    ($(#[$attr:meta])* $variant:ident => $name:ident) => {
-        #[derive(Debug, Clone, PartialEq)]
-        #[repr(transparent)]
-        $(#[$attr])*
-        pub struct $name(RedNode);
-
-        impl TypedNode for $name {
-            fn cast_from(node: RedRef) -> Option<Self> {
-                if node.kind() != &NodeKind::$variant {
-                    return None;
-                }
-
-                Some(Self(node.own()))
-            }
-        }
-
-        impl $name {
-            pub fn span(&self) -> Span {
-                self.0.span()
-            }
-
-            pub fn underlying(&self) -> RedRef {
-                self.0.as_ref()
-            }
-        }
-    };
-}