diff --git a/src/diag.rs b/src/diag.rs
index 61432e93..6249a7cd 100644
--- a/src/diag.rs
+++ b/src/diag.rs
@@ -5,6 +5,7 @@ use serde::{Deserialize, Serialize};
 use crate::syntax::{Span, Spanned};
 
 /// Early-return with a vec-boxed [`Error`].
+#[macro_export]
 macro_rules! bail {
     ($span:expr, $message:expr $(,)?) => {
         return Err($crate::diag::Error::boxed($span, $message,))
diff --git a/src/export/pdf.rs b/src/export/pdf.rs
index b762060e..3abda916 100644
--- a/src/export/pdf.rs
+++ b/src/export/pdf.rs
@@ -309,10 +309,10 @@ impl<'a> PdfExporter<'a> {
             let face = self.fonts.get(face_id);
             let ttf = face.ttf();
 
-            let postcript_name = find_name(ttf.names(), name_id::POST_SCRIPT_NAME)
+            let postscript_name = find_name(ttf.names(), name_id::POST_SCRIPT_NAME)
                 .unwrap_or_else(|| "unknown".to_string());
 
-            let base_font = format!("ABCDEF+{}", postcript_name);
+            let base_font = format!("ABCDEF+{}", postscript_name);
             let base_font = Name(base_font.as_bytes());
             let cmap_name = Name(b"Custom");
             let system_info = SystemInfo {
@@ -356,7 +356,7 @@ impl<'a> PdfExporter<'a> {
                 });
 
             let mut flags = FontFlags::empty();
-            flags.set(FontFlags::SERIF, postcript_name.contains("Serif"));
+            flags.set(FontFlags::SERIF, postscript_name.contains("Serif"));
             flags.set(FontFlags::FIXED_PITCH, ttf.is_monospaced());
             flags.set(FontFlags::ITALIC, ttf.is_italic());
             flags.insert(FontFlags::SYMBOLIC);
diff --git a/src/layout/tree.rs b/src/layout/tree.rs
index 28cbbb51..36d0ac25 100644
--- a/src/layout/tree.rs
+++ b/src/layout/tree.rs
@@ -2,13 +2,12 @@ use std::fmt::{self, Debug, Formatter};
 
 use super::*;
 
-use std::any::Any;
-
 #[cfg(feature = "layout-cache")]
-use std::hash::{Hash, Hasher};
-
-#[cfg(feature = "layout-cache")]
-use fxhash::FxHasher64;
+use {
+    fxhash::FxHasher64,
+    std::any::Any,
+    std::hash::{Hash, Hasher},
+};
 
 /// A tree of layout nodes.
 #[derive(Debug)]
diff --git a/src/library/text.rs b/src/library/text.rs
index 863586f6..b8b3afcd 100644
--- a/src/library/text.rs
+++ b/src/library/text.rs
@@ -1,6 +1,5 @@
-use crate::layout::{Decoration, LineDecoration, LineKind, Paint};
-
 use super::*;
+use crate::layout::{Decoration, LineDecoration, LineKind, Paint};
 
 /// `font`: Configure the font.
 pub fn font(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
@@ -163,22 +162,22 @@ fn lang_dir(iso: &str) -> Dir {
     }
 }
 
-/// `strike`: Set striken-through text.
-pub fn strike(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
-    line_impl(ctx, args, LineKind::Strikethrough)
+/// `strike`: Typeset striken-through text.
+pub fn strike(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
+    line_impl(args, LineKind::Strikethrough)
 }
 
-/// `underline`: Set underlined text.
-pub fn underline(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
-    line_impl(ctx, args, LineKind::Underline)
+/// `underline`: Typeset underlined text.
+pub fn underline(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
+    line_impl(args, LineKind::Underline)
 }
 
-/// `overline`: Set text with an overline.
-pub fn overline(ctx: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
-    line_impl(ctx, args, LineKind::Overline)
+/// `overline`: Typeset text with an overline.
+pub fn overline(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
+    line_impl(args, LineKind::Overline)
 }
 
-fn line_impl(_: &mut EvalContext, args: &mut Args, kind: LineKind) -> TypResult<Value> {
+fn line_impl(args: &mut Args, kind: LineKind) -> TypResult<Value> {
     let stroke = args.named("stroke")?.or_else(|| args.eat());
     let thickness = args.named::<Linear>("thickness")?.or_else(|| args.eat());
     let offset = args.named("offset")?;
@@ -196,7 +195,7 @@ fn line_impl(_: &mut EvalContext, args: &mut Args, kind: LineKind) -> TypResult<
     Ok(Value::Template(body))
 }
 
-/// `link`: Set a link.
+/// `link`: Typeset text as a link.
 pub fn link(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
     let url = args.expect::<Str>("url")?;
 
diff --git a/src/library/utility.rs b/src/library/utility.rs
index f5fab6ee..e6d5476f 100644
--- a/src/library/utility.rs
+++ b/src/library/utility.rs
@@ -1,9 +1,8 @@
 use std::cmp::Ordering;
 use std::str::FromStr;
 
-use crate::color::{Color, RgbaColor};
-
 use super::*;
+use crate::color::{Color, RgbaColor};
 
 /// `type`: The name of a value's type.
 pub fn type_(_: &mut EvalContext, args: &mut Args) -> TypResult<Value> {
diff --git a/src/parse/mod.rs b/src/parse/mod.rs
index 649b4eb8..498badca 100644
--- a/src/parse/mod.rs
+++ b/src/parse/mod.rs
@@ -17,7 +17,7 @@ use crate::source::SourceFile;
 use crate::syntax::*;
 use crate::util::EcoString;
 
-/// Parse a string of source code.
+/// Parse a source file.
 pub fn parse(source: &SourceFile) -> TypResult<SyntaxTree> {
     let mut p = Parser::new(source);
     let tree = tree(&mut p);
@@ -48,13 +48,14 @@ fn tree_indented(p: &mut Parser, column: usize) -> SyntaxTree {
     })
 }
 
-/// Parse a syntax tree.
+/// Parse a syntax tree while the peeked token satisifies a condition.
+///
+/// If `at_start` is true, things like headings that may only appear at the
+/// beginning of a line or template are allowed.
 fn tree_while<F>(p: &mut Parser, mut at_start: bool, f: &mut F) -> SyntaxTree
 where
     F: FnMut(&mut Parser) -> bool,
 {
-    // We use `at_start` to keep track of whether we are at the start of a line
-    // or template to know whether things like headings are allowed.
     let mut tree = vec![];
     while !p.eof() && f(p) {
         if let Some(node) = node(p, &mut at_start) {
@@ -94,8 +95,8 @@ fn node(p: &mut Parser, at_start: &mut bool) -> Option<SyntaxNode> {
         Token::Underscore => SyntaxNode::Emph(span),
         Token::Raw(t) => raw(p, t),
         Token::Eq if *at_start => return Some(heading(p)),
-        Token::Hyph if *at_start => return Some(list_item(p)),
-        Token::Numbering(number) if *at_start => return Some(enum_item(p, number)),
+        Token::Hyph if *at_start => return Some(list_node(p)),
+        Token::Numbering(number) if *at_start => return Some(enum_node(p, number)),
 
         // Line-based markup that is not currently at the start of the line.
         Token::Eq | Token::Hyph | Token::Numbering(_) => {
@@ -196,7 +197,7 @@ fn heading(p: &mut Parser) -> SyntaxNode {
 }
 
 /// Parse a single list item.
-fn list_item(p: &mut Parser) -> SyntaxNode {
+fn list_node(p: &mut Parser) -> SyntaxNode {
     let start = p.next_start();
     let column = p.column(start);
     p.eat_assert(Token::Hyph);
@@ -205,7 +206,7 @@ fn list_item(p: &mut Parser) -> SyntaxNode {
 }
 
 /// Parse a single enum item.
-fn enum_item(p: &mut Parser, number: Option<usize>) -> SyntaxNode {
+fn enum_node(p: &mut Parser, number: Option<usize>) -> SyntaxNode {
     let start = p.next_start();
     let column = p.column(start);
     p.eat_assert(Token::Numbering(number));
@@ -243,10 +244,7 @@ fn expr_with(p: &mut Parser, atomic: bool, min_prec: usize) -> Option<Expr> {
     loop {
         // Exclamation mark, parenthesis or bracket means this is a function
         // call.
-        if matches!(
-            p.peek_direct(),
-            Some(Token::Excl | Token::LeftParen | Token::LeftBracket),
-        ) {
+        if matches!(p.peek_direct(), Some(Token::LeftParen | Token::LeftBracket)) {
             lhs = call(p, lhs)?;
             continue;
         }
@@ -520,7 +518,7 @@ fn idents(p: &mut Parser, items: Vec<CallArg>) -> Vec<Ident> {
     iter.collect()
 }
 
-// Parse a template value: `[...]`.
+// Parse a template block: `[...]`.
 fn template(p: &mut Parser) -> Expr {
     p.start_group(Group::Bracket, TokenMode::Markup);
     let tree = tree(p);
@@ -528,7 +526,7 @@ fn template(p: &mut Parser) -> Expr {
     Expr::Template(Box::new(TemplateExpr { span, tree }))
 }
 
-/// Parse a block expression: `{...}`.
+/// Parse a code block: `{...}`.
 fn block(p: &mut Parser, scoping: bool) -> Expr {
     p.start_group(Group::Brace, TokenMode::Code);
     let mut exprs = vec![];
diff --git a/src/parse/tokens.rs b/src/parse/tokens.rs
index 91d3ab7f..c6bf3a90 100644
--- a/src/parse/tokens.rs
+++ b/src/parse/tokens.rs
@@ -142,7 +142,6 @@ impl<'s> Tokens<'s> {
             '-' => Token::Hyph,
             '*' => Token::Star,
             '/' => Token::Slash,
-            '!' => Token::Excl,
             '=' => Token::Eq,
             '<' => Token::Lt,
             '>' => Token::Gt,
diff --git a/src/source.rs b/src/source.rs
index b02af1b6..ac56f7ce 100644
--- a/src/source.rs
+++ b/src/source.rs
@@ -6,14 +6,15 @@ use std::ops::Range;
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
-#[cfg(feature = "codespan-reporting")]
-use codespan_reporting::files::{self, Files};
 use serde::{Deserialize, Serialize};
 
 use crate::loading::{FileHash, Loader};
 use crate::parse::{is_newline, Scanner};
 use crate::util::PathExt;
 
+#[cfg(feature = "codespan-reporting")]
+use codespan_reporting::files::{self, Files};
+
 /// A unique identifier for a loaded source file.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 pub struct SourceId(u32);
diff --git a/src/syntax/ident.rs b/src/syntax/ident.rs
index c47e6fb1..398e2ff9 100644
--- a/src/syntax/ident.rs
+++ b/src/syntax/ident.rs
@@ -1,3 +1,4 @@
+use std::borrow::Borrow;
 use std::ops::Deref;
 
 use unicode_xid::UnicodeXID;
@@ -53,6 +54,18 @@ impl AsRef<str> for Ident {
     }
 }
 
+impl Borrow<str> for Ident {
+    fn borrow(&self) -> &str {
+        self
+    }
+}
+
+impl From<&Ident> for EcoString {
+    fn from(ident: &Ident) -> Self {
+        ident.string.clone()
+    }
+}
+
 /// Whether a string is a valid identifier.
 pub fn is_ident(string: &str) -> bool {
     let mut chars = string.chars();
diff --git a/src/syntax/token.rs b/src/syntax/token.rs
index 219395cf..22dd104b 100644
--- a/src/syntax/token.rs
+++ b/src/syntax/token.rs
@@ -39,8 +39,6 @@ pub enum Token<'s> {
     Hyph,
     /// A slash: `/`.
     Slash,
-    /// An exlamation mark.
-    Excl,
     /// A single equals sign: `=`.
     Eq,
     /// Two equals signs: `==`.
@@ -223,7 +221,6 @@ impl<'s> Token<'s> {
             Self::Plus => "plus",
             Self::Hyph => "minus",
             Self::Slash => "slash",
-            Self::Excl => "exclamation mark",
             Self::Eq => "assignment operator",
             Self::EqEq => "equality operator",
             Self::ExclEq => "inequality operator",
diff --git a/src/util/eco.rs b/src/util/eco_string.rs
similarity index 100%
rename from src/util/eco.rs
rename to src/util/eco_string.rs
diff --git a/src/util/mac.rs b/src/util/mac_roman.rs
similarity index 100%
rename from src/util/mac.rs
rename to src/util/mac_roman.rs
diff --git a/src/util/mod.rs b/src/util/mod.rs
index 1abdcbc9..05dc9025 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1,10 +1,10 @@
 //! Utilities.
 
-mod eco;
-mod mac;
+mod eco_string;
+mod mac_roman;
 
-pub use eco::EcoString;
-pub use mac::decode_mac_roman;
+pub use eco_string::EcoString;
+pub use mac_roman::decode_mac_roman;
 
 use std::cell::RefMut;
 use std::cmp::Ordering;