immutable iteration for parallel access

examples/corpus_node_model.rs

@@ -41,7 +41,7 @@ pub fn main() -> Result<(), Error> {
     node_model_file,
   )));
 
-  let mut corpus = Corpus::new(corpus_path);
+  let corpus = Corpus::new(corpus_path);
   let total_counts = corpus.catalog_with_parallel_walk(|document| {
     // Recursively descend the dom DFS and record to the token model
     let mut total_counts = HashMap::new();

examples/corpus_token_model.rs

@@ -51,7 +51,7 @@ pub fn main() {
   // Integers, floats, subfigure numbers
   let is_numeric = Regex::new(r"^-?(?:\d+)(?:[a-k]|(?:\.\d+(?:[eE][+-]?\d+)?))?$").unwrap();
 
-  let mut corpus = Corpus::new(corpus_path);
+  let corpus = Corpus::new(corpus_path);
   let corpus_counts = corpus.catalog_with_parallel_walk(|document| {
     let (
       mut sentence_count,

examples/pre_ref_words.rs

@@ -36,7 +36,7 @@ pub fn main() -> Result<(), Error> {
 
   let node_statistics_file = File::create(node_statistics_filepath)?;
 
-  let mut corpus = Corpus::new(corpus_path);
+  let corpus = Corpus::new(corpus_path);
 
   let catalog = corpus.catalog_with_parallel_walk(|document| {
     println!(

src/parallel_data.rs

@@ -118,7 +118,7 @@ impl Corpus {
   }
 
   /// Get a parallel iterator over the documents
-  pub fn catalog_with_parallel_walk<F>(&mut self, closure: F) -> HashMap<String, u64>
+  pub fn catalog_with_parallel_walk<F>(&self, closure: F) -> HashMap<String, u64>
   where
     F: Fn(Document) -> HashMap<String, u64> + Send + Sync,
   {

tests/parallel_test.rs

@@ -1,9 +1,9 @@
+use llamapun::parallel_data::Corpus;
 use std::collections::HashMap;
-use llamapun::parallel_data::{Corpus};
 
 #[test]
 fn can_iterate_corpus() {
-  let mut corpus = Corpus::new("tests".to_string());
+  let corpus = Corpus::new("tests".to_string());
   let catalog = corpus.catalog_with_parallel_walk(|document| {
     let mut thread_count = HashMap::new();
     thread_count.insert(String::from("doc_count"), 1);