Adopt and apply nightly clippy configuration

src/syntax/content/parser/token/anchor.rs

@@ -28,15 +28,21 @@ impl Anchor {
         self.route();
     }
 
-    pub fn balanced(&self) -> bool { self.balanced }
+    pub const fn balanced(&self) -> bool { self.balanced }
 
-    pub fn set_balanced(&mut self, balanced: bool) { self.balanced = balanced; }
+    pub const fn set_balanced(&mut self, balanced: bool) {
+        self.balanced = balanced;
+    }
 
-    pub fn external(&self) -> bool { self.external }
+    pub const fn external(&self) -> bool { self.external }
 
-    pub fn set_external(&mut self, external: bool) { self.external = external; }
+    pub const fn set_external(&mut self, external: bool) {
+        self.external = external;
+    }
 
-    pub fn set_leading(&mut self, leading: bool) { self.leading = leading; }
+    pub const fn set_leading(&mut self, leading: bool) {
+        self.leading = leading;
+    }
 
     pub fn node(&self) -> Option<Node> { self.node.clone() }
 
@@ -52,7 +58,7 @@ impl Anchor {
 
     fn route(&mut self) {
         self.destination = if let Some(destination) = self.destination.clone() {
-            if destination.contains(":") || destination.contains("/") {
+            if destination.contains(':') || destination.contains('/') {
                 Some(destination)
             } else if destination.is_empty() && self.text.is_empty() {
                 None

src/syntax/content/parser/token/bold.rs

@@ -6,7 +6,7 @@ pub struct Bold {
 }
 
 impl Bold {
-    pub fn new(open: bool) -> Bold { Bold { open } }
+    pub const fn new(open: bool) -> Bold { Bold { open } }
 }
 
 impl Parseable for Bold {

src/syntax/content/parser/token/checkbox.rs

@@ -6,7 +6,7 @@ pub struct CheckBox {
 }
 
 impl CheckBox {
-    pub fn new(checked: bool) -> CheckBox { CheckBox { checked } }
+    pub const fn new(checked: bool) -> CheckBox { CheckBox { checked } }
 }
 
 impl Parseable for CheckBox {

src/syntax/content/parser/token/code.rs

@@ -6,7 +6,7 @@ pub struct Code {
 }
 
 impl Code {
-    pub fn new(open: bool) -> Code { Code { open } }
+    pub const fn new(open: bool) -> Code { Code { open } }
 }
 
 impl Parseable for Code {

src/syntax/content/parser/token/header.rs

@@ -32,7 +32,7 @@ impl Header {
     ) -> String {
         let base_id = if !config.ascii_dom_ids || next_lexeme.next().is_ascii()
         {
-            next_lexeme.next().clone()
+            next_lexeme.next()
         } else {
             String::from("h")
         };
@@ -60,7 +60,7 @@ impl Header {
         }
     }
 
-    pub fn level(&self) -> u8 {
+    pub const fn level(&self) -> u8 {
         match self.level {
             Level::One => 1,
             Level::Two => 2,
@@ -147,7 +147,7 @@ pub enum Level {
 }
 
 impl Level {
-    fn from_u8(u: u8) -> Level {
+    const fn from_u8(u: u8) -> Level {
         if u <= 1 {
             Level::One
         } else if u == 2 {

src/syntax/content/parser/token/linebreak.rs

@@ -1,7 +1,7 @@
 use crate::syntax::content::{Parseable, parser::Lexeme};
 
 #[derive(Default, Debug, Clone, Eq, PartialEq)]
-pub struct LineBreak {}
+pub struct LineBreak;
 
 impl Parseable for LineBreak {
     fn probe(lexeme: &Lexeme) -> bool {

src/syntax/content/parser/token/list.rs

@@ -43,19 +43,19 @@ impl Parseable for List {
                 .unwrap_or(0)
                 .strict_div(scale);
 
-            output.push_str(&format!("<li>{}", item.text));
+            write_log!(output, "<li>{}", item.text);
 
             if next_level > level {
                 // open nested lists
                 for _ in 0..(next_level.saturating_sub(level)) {
-                    output.push_str(&format!("<{tag}>\n"));
+                    write_log!(output, "<{tag}>\n");
                 }
             } else {
                 // close current item
                 output.push_str("</li>");
                 // close nested lists
                 for _ in 0..(level.saturating_sub(next_level)) {
-                    output.push_str(&format!("</{tag}></li>"));
+                    write_log!(output, "</{tag}></li>");
                 }
                 output.push('\n');
             }
@@ -70,7 +70,7 @@ impl Parseable for List {
 }
 
 impl List {
-    pub fn new(ordered: bool) -> List {
+    pub const fn new(ordered: bool) -> List {
         List {
             ordered,
             items: vec![],
@@ -202,7 +202,7 @@ mod tests {
     fn token_display() {
         let list = List::new(false);
         assert_eq!(
-            format!("{}", Token::List(list.clone())),
+            format!("{}", Token::List(list)),
             "Tk:List [0 unordered items]"
         );
     }

src/syntax/content/parser/token/oblique.rs

@@ -6,7 +6,7 @@ pub struct Oblique {
 }
 
 impl Oblique {
-    pub fn new(open: bool) -> Oblique { Oblique { open } }
+    pub const fn new(open: bool) -> Oblique { Oblique { open } }
 }
 
 impl Parseable for Oblique {

src/syntax/content/parser/token/paragraph.rs

@@ -6,7 +6,7 @@ pub struct Paragraph {
 }
 
 impl Paragraph {
-    pub fn new(open: bool) -> Paragraph { Paragraph { open: Some(open) } }
+    pub const fn new(open: bool) -> Paragraph { Paragraph { open: Some(open) } }
 
     pub fn probe_end(lexeme: &Lexeme) -> bool {
         lexeme.match_char('\n') && lexeme.match_next_char('\n')

src/syntax/content/parser/token/preformat.rs

@@ -6,7 +6,7 @@ pub struct PreFormat {
 }
 
 impl PreFormat {
-    pub fn new(open: bool) -> PreFormat { PreFormat { open: Some(open) } }
+    pub const fn new(open: bool) -> PreFormat { PreFormat { open: Some(open) } }
 }
 
 impl std::fmt::Display for PreFormat {

src/syntax/content/parser/token/strike.rs

@@ -6,7 +6,7 @@ pub struct Strike {
 }
 
 impl Strike {
-    pub fn new(open: bool) -> Strike { Strike { open } }
+    pub const fn new(open: bool) -> Strike { Strike { open } }
 }
 
 impl Parseable for Strike {

src/syntax/content/parser/token/underline.rs

@@ -6,7 +6,7 @@ pub struct Underline {
 }
 
 impl Underline {
-    pub fn new(open: bool) -> Underline { Underline { open } }
+    pub const fn new(open: bool) -> Underline { Underline { open } }
 }
 
 impl Parseable for Underline {

src/syntax/content/parser/token/verse.rs

@@ -7,7 +7,7 @@ pub struct Verse {
 }
 
 impl Verse {
-    pub fn new(open: bool) -> Verse {
+    pub const fn new(open: bool) -> Verse {
         Verse {
             open: Some(open),
             citation: None,