Const it up

Cargo.toml

@@ -23,6 +23,7 @@ complexity = "deny"
 perf = "deny"
 must_use_candidate = "deny"
 doc_markdown = "deny"
+missing_const_for_fn = "deny"
 
 [dependencies]
 tracing = { version = "0.1.37", optional = true }

src/earley/input_range.rs

@@ -5,7 +5,7 @@ pub(crate) struct InputRangeOffset {
 }
 
 impl InputRangeOffset {
-    pub fn total_len(&self) -> usize {
+    pub const fn total_len(&self) -> usize {
         self.start + self.len
     }
 }
@@ -18,7 +18,7 @@ pub(crate) struct InputRange<'gram> {
 }
 
 impl<'gram> InputRange<'gram> {
-    pub fn new(input: &'gram str) -> Self {
+    pub const fn new(input: &'gram str) -> Self {
         Self {
             input,
             offset: InputRangeOffset { start: 0, len: 0 },
@@ -28,7 +28,7 @@ impl<'gram> InputRange<'gram> {
         let next_idx = self.offset.start + self.offset.len;
         &self.input[next_idx..]
     }
-    pub fn after(&self) -> Self {
+    pub const fn after(&self) -> Self {
         Self {
             input: self.input,
             offset: InputRangeOffset {
@@ -46,7 +46,7 @@ impl<'gram> InputRange<'gram> {
             offset: InputRangeOffset { start, len },
         }
     }
-    pub fn is_complete(&self) -> bool {
+    pub const fn is_complete(&self) -> bool {
         self.offset.start == 0 && self.offset.len == self.input.len()
     }
 }

src/earley/mod.rs

@@ -208,13 +208,13 @@ pub(crate) struct CompletionKey<'gram> {
 }
 
 impl<'gram> CompletionKey<'gram> {
-    pub fn new_start(term: &'gram Term, input: &InputRange<'gram>) -> Self {
+    pub const fn new_start(term: &'gram Term, input: &InputRange<'gram>) -> Self {
         Self {
             term,
             input_start: input.offset.start,
         }
     }
-    pub fn new_total(term: &'gram Term, input: &InputRange<'gram>) -> Self {
+    pub const fn new_total(term: &'gram Term, input: &InputRange<'gram>) -> Self {
         Self {
             term,
             input_start: input.offset.total_len(),

src/earley/traversal.rs

@@ -35,7 +35,7 @@ pub(crate) struct Traversal<'gram> {
 }
 
 impl<'gram> Traversal<'gram> {
-    pub fn next_unmatched(&self) -> Option<&'gram Term> {
+    pub const fn next_unmatched(&self) -> Option<&'gram Term> {
         self.unmatched.first()
     }
 }

src/expression.rs

@@ -15,13 +15,13 @@ pub struct Expression {
 impl Expression {
     /// Construct a new `Expression`
     #[must_use]
-    pub fn new() -> Expression {
+    pub const fn new() -> Expression {
         Expression { terms: vec![] }
     }
 
     /// Construct an `Expression` from `Term`s
     #[must_use]
-    pub fn from_parts(v: Vec<Term>) -> Expression {
+    pub const fn from_parts(v: Vec<Term>) -> Expression {
         Expression { terms: v }
     }
 

src/grammar.rs

@@ -127,7 +127,7 @@ impl<'gram> ParseTree<'gram> {
     /// println!("parse tree mermaid: {}", mermaid);
     /// ```
     #[must_use]
-    pub fn mermaid(&self) -> MermaidParseTree<'_> {
+    pub const fn mermaid(&self) -> MermaidParseTree<'_> {
         MermaidParseTree { parse_tree: self }
     }
 
@@ -212,15 +212,15 @@ pub struct Grammar {
 impl Grammar {
     /// Construct a new `Grammar`
     #[must_use]
-    pub fn new() -> Grammar {
+    pub const fn new() -> Grammar {
         Grammar {
             productions: vec![],
         }
     }
 
     /// Construct an `Grammar` from `Production`s
     #[must_use]
-    pub fn from_parts(v: Vec<Production>) -> Grammar {
+    pub const fn from_parts(v: Vec<Production>) -> Grammar {
         Grammar { productions: v }
     }