diff --git a/sgf/src/date.rs b/sgf/src/date.rs
index 3058174..8de0e1b 100644
--- a/sgf/src/date.rs
+++ b/sgf/src/date.rs
@@ -1,6 +1,6 @@
 use chrono::{Datelike, NaiveDate};
 use serde::{Deserialize, Serialize};
-use std::num::ParseIntError;
+use std::{fmt, num::ParseIntError};
 use thiserror::Error;
 use typeshare::typeshare;
 
@@ -11,9 +11,6 @@ pub enum Error {
 
     #[error("Invalid date")]
     InvalidDate,
-
-    #[error("unsupported date format")]
-    Unsupported,
 }
 
 #[derive(Clone, Debug, PartialEq, PartialOrd, Deserialize, Serialize)]
@@ -24,12 +21,12 @@ pub enum Date {
     Date(chrono::NaiveDate),
 }
 
-impl Date {
-    pub fn to_string(&self) -> String {
+impl fmt::Display for Date {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            Date::Year(y) => format!("{}", y),
-            Date::YearMonth(y, m) => format!("{}-{}", y, m),
-            Date::Date(date) => format!("{}-{}-{}", date.year(), date.month(), date.day()),
+            Date::Year(y) => write!(f, "{}", y),
+            Date::YearMonth(y, m) => write!(f, "{}-{}", y, m),
+            Date::Date(date) => write!(f, "{}-{}-{}", date.year(), date.month(), date.day()),
         }
     }
 }
@@ -71,13 +68,13 @@ impl TryFrom<&str> for Date {
 */
 
 fn parse_numbers(s: &str) -> Result<Vec<i32>, Error> {
-    s.split("-")
-        .map(|s| s.parse::<i32>().map_err(|err| Error::ParseNumberError(err)))
+    s.split('-')
+        .map(|s| s.parse::<i32>().map_err(Error::ParseNumberError))
         .collect::<Result<Vec<i32>, Error>>()
 }
 
 pub fn parse_date_field(s: &str) -> Result<Vec<Date>, Error> {
-    let date_elements = s.split(",");
+    let date_elements = s.split(',');
     let mut dates = Vec::new();
 
     let mut most_recent: Option<Date> = None;
@@ -96,9 +93,9 @@ pub fn parse_date_field(s: &str) -> Result<Vec<Date>, Error> {
                 None => Date::Year(*v1),
             },
             [v1, v2] => Date::YearMonth(*v1, *v2 as u32),
-            [v1, v2, v3, ..] => Date::Date(
-                NaiveDate::from_ymd_opt(v1.clone(), v2.clone() as u32, v3.clone() as u32).unwrap(),
-            ),
+            [v1, v2, v3, ..] => {
+                Date::Date(NaiveDate::from_ymd_opt(*v1, *v2 as u32, *v3 as u32).unwrap())
+            }
         };
         dates.push(new_date.clone());
         most_recent = Some(new_date);
diff --git a/sgf/src/go.rs b/sgf/src/go.rs
index d0fa213..2c226f4 100644
--- a/sgf/src/go.rs
+++ b/sgf/src/go.rs
@@ -95,6 +95,7 @@ impl Deref for Game {
 impl TryFrom<Tree> for Game {
     type Error = Error;
 
+    #[allow(clippy::field_reassign_with_default)]
     fn try_from(tree: Tree) -> Result<Self, Self::Error> {
         let board_size = match tree.root.find_prop("SZ") {
             Some(prop) => Size::try_from(prop.values[0].as_str())?,
@@ -131,7 +132,7 @@ impl TryFrom<Tree> for Game {
             .root
             .find_prop("TM")
             .and_then(|prop| prop.values[0].parse::<u64>().ok())
-            .and_then(|seconds| Some(std::time::Duration::from_secs(seconds)));
+            .map(std::time::Duration::from_secs);
 
         info.date = tree
             .root
@@ -182,7 +183,7 @@ pub enum Rank {
 impl TryFrom<&str> for Rank {
     type Error = String;
     fn try_from(r: &str) -> Result<Rank, Self::Error> {
-        let parts = r.split(" ").map(|s| s.to_owned()).collect::<Vec<String>>();
+        let parts = r.split(' ').map(|s| s.to_owned()).collect::<Vec<String>>();
         let cnt = parts[0].parse::<u8>().map_err(|err| format!("{:?}", err))?;
         match parts[1].to_ascii_lowercase().as_str() {
             "kyu" => Ok(Rank::Kyu(cnt)),
@@ -250,7 +251,7 @@ impl TryFrom<&str> for GameResult {
         } else if s == "Void" {
             Ok(GameResult::Annulled)
         } else {
-            let parts = s.split("+").collect::<Vec<&str>>();
+            let parts = s.split('+').collect::<Vec<&str>>();
             let res = match parts[0].to_ascii_lowercase().as_str() {
                 "b" => GameResult::Black,
                 "w" => GameResult::White,
diff --git a/sgf/src/lib.rs b/sgf/src/lib.rs
index bd2937c..3c42229 100644
--- a/sgf/src/lib.rs
+++ b/sgf/src/lib.rs
@@ -51,7 +51,7 @@ impl From<nom::error::Error<&str>> for ParseError {
     fn from(err: nom::error::Error<&str>) -> Self {
         Self::NomError(nom::error::Error {
             input: err.input.to_owned(),
-            code: err.code.clone(),
+            code: err.code,
         })
     }
 }
diff --git a/sgf/src/tree.rs b/sgf/src/tree.rs
index e1340a2..167353d 100644
--- a/sgf/src/tree.rs
+++ b/sgf/src/tree.rs
@@ -2,7 +2,7 @@ use crate::Error;
 use nom::{
     branch::alt,
     bytes::complete::{escaped_transform, tag},
-    character::complete::{alpha1, digit1, multispace0, multispace1, none_of},
+    character::complete::{alpha1, multispace0, multispace1, none_of},
     combinator::{opt, value},
     multi::{many0, many1, separated_list1},
     IResult,
@@ -101,7 +101,7 @@ impl Node {
             .cloned()
     }
 
-    pub fn next<'a>(&'a self) -> Option<&'a Node> {
+    pub fn next(&self) -> Option<&Node> {
         self.next.get(0)
     }
 }
@@ -209,21 +209,6 @@ fn parse_propval_text<'a, E: nom::error::ParseError<&'a str>>(
     Ok((input, value.map(|v| v.to_owned())))
 }
 
-pub fn parse_size<'a, E: nom::error::ParseError<&'a str>>(
-    input: &'a str,
-) -> IResult<&'a str, Size, E> {
-    let (input, dimensions) = separated_list1(tag(":"), digit1)(input)?;
-    let (width, height) = match dimensions.as_slice() {
-        [width] => (width.parse::<i32>().unwrap(), width.parse::<i32>().unwrap()),
-        [width, height] => (
-            width.parse::<i32>().unwrap(),
-            height.parse::<i32>().unwrap(),
-        ),
-        _ => (19, 19),
-    };
-    Ok((input, Size { width, height }))
-}
-
 #[cfg(test)]
 mod test {
     use super::*;