6 files changed, 4 insertions, 12 deletions
diff --git a/src/compiler.rs b/src/compiler.rs
index 061d3e3..b0061ce 100644
--- a/src/compiler.rs
+++ b/src/compiler.rs
@@ -1,4 +1,5 @@
 //! Turn events into a string of HTML.
+use std::collections::HashMap;
 use crate::constant::{SAFE_PROTOCOL_HREF, SAFE_PROTOCOL_SRC};
 use crate::construct::character_reference::Kind as CharacterReferenceKind;
 use crate::tokenizer::{Code, Event, EventType, TokenType};
@@ -9,7 +10,6 @@ use crate::util::{
     sanitize_uri::sanitize_uri,
     span::{codes as codes_from_span, from_exit_event, serialize},
 };
-use std::collections::HashMap;
 
 /// Type of line endings in markdown.
 #[derive(Debug, Clone, PartialEq)]
@@ -725,7 +725,6 @@ fn on_exit_autolink_email(context: &mut CompileContext) {
         &from_exit_event(context.events, context.index),
         false,
     );
-    // To do:
     context.tag(format!(
         "<a href=\"{}\">",
         sanitize_uri(
diff --git a/src/content/flow.rs b/src/content/flow.rs
index 3ff948d..4a12e0f 100644
--- a/src/content/flow.rs
+++ b/src/content/flow.rs
@@ -19,6 +19,7 @@
 //! *   [HTML (flow)][crate::construct::html_flow]
 //! *   [Thematic break][crate::construct::thematic_break]
 
+use std::collections::HashSet;
 use crate::construct::{
     blank_line::start as blank_line, code_fenced::start as code_fenced,
     code_indented::start as code_indented, definition::start as definition,
@@ -33,7 +34,6 @@ use crate::util::{
     normalize_identifier::normalize_identifier,
     span::{from_exit_event, serialize},
 };
-use std::collections::HashSet;
 
 /// Turn `codes` as the flow content type into events.
 pub fn flow(parse_state: &mut ParseState, point: Point, index: usize) -> Vec<Event> {
diff --git a/src/parser.rs b/src/parser.rs
index f11f0d1..89a0de1 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,12 +1,10 @@
 //! Turn a string of markdown into events.
 
+use std::collections::HashSet;
 // To do: this should start with `containers`, when they’re done.
 use crate::content::flow::flow;
 use crate::tokenizer::{as_codes, Code, Event, Point};
 
-/// To do: could we do without `HashSet`, so we don’t need `std`?
-use std::collections::HashSet;
-
 /// Information needed, in all content types, when parsing markdown.
 ///
 /// Importantly, this contains a set of known definitions.
diff --git a/src/subtokenize.rs b/src/subtokenize.rs
index 92ada04..ad8aace 100644
--- a/src/subtokenize.rs
+++ b/src/subtokenize.rs
@@ -21,9 +21,7 @@
 //! thus the whole document needs to be parsed up to the level of definitions,
 //! before any level that can include references can be parsed.
 
-/// To do: could we do without `HashMap`, so we don’t need `std`?
 use std::collections::HashMap;
-
 use crate::content::{string::start as string, text::start as text};
 use crate::parser::ParseState;
 use crate::tokenizer::{ContentType, Event, EventType, State, StateFn, StateFnResult, Tokenizer};
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index 282c99f..9d870c9 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -11,9 +11,7 @@
 //! [`attempt`]: Tokenizer::attempt
 //! [`check`]: Tokenizer::check
 
-/// To do: could we do without `HashMap`, so we don’t need `std`?
 use std::collections::HashMap;
-
 use crate::constant::TAB_SIZE;
 use crate::parser::ParseState;
 
diff --git a/src/util/edit_map.rs b/src/util/edit_map.rs
index 665367a..417f42b 100644
--- a/src/util/edit_map.rs
+++ b/src/util/edit_map.rs
@@ -8,9 +8,7 @@
 //! And, in other cases, it’s needed to parse subcontent: pass some events
 //! through another tokenizer and inject the result.
 
-/// To do: could we do without `HashMap`, so we don’t need `std`?
 use std::collections::HashMap;
-
 use crate::tokenizer::Event;
 
 /// Shift `previous` and `next` links according to `jumps`.
@@ -136,6 +134,7 @@ impl EditMap {
     }
 }
 
+/// To do.
 fn add_impl(
     edit_map: &mut EditMap,
     index: usize,