control thread pool size, api tweak, typo

src/args.rs

@@ -99,7 +99,7 @@ pub struct Args {
     #[arg(
         short='X', long,
         help = "exclude from search and printing",
-        long_help = "exclude from search and printin. accepts glob syntax. separate rules by comma",
+        long_help = "exclude from search and printing. accepts glob syntax. separate rules by comma",
         value_parser = parse_glob,
         value_delimiter = ',',
         action = ArgAction::Append,
@@ -115,6 +115,14 @@ pub struct Args {
     )]
     show_hidden: bool,
 
+    #[arg(
+        short='j', long,
+        help="control size of thread pool",
+        long_help="set the number of threads in the thread pool. Using zero uses the default number of threads, equal to RAYON_NUM_THREADS if set, or the number of logical CPUs otherwise",
+        default_value_t = 0,
+    )]
+    threads: usize,
+
     #[arg(
         value_parser = validate_path,
         help = "items to summate",
@@ -127,24 +135,22 @@ impl Args {
     /// utility method to chuck default values on the end.
     /// it feels like I should be able to do this with
     /// clever `clap` macros but I don't know how
-    pub fn parse_and_process() -> Self {
-        let mut this = Self::parse();
-        
-        if this.base_two {
-            this.unit = Unit::Kibi;
-        } else if this.si {
-            this.unit = Unit::Kilo;
+    pub fn post_process(mut self) -> Self {        
+        if self.base_two {
+            self.unit = Unit::Kibi;
+        } else if self.si {
+            self.unit = Unit::Kilo;
         }
 
-        if this.show_hidden {
-            this.exclude_print = Vec::new();
+        if self.show_hidden {
+            self.exclude_print.clear();
         }
 
-        if this.path.is_empty() {
-            this.path = vec![ ".".to_owned() ];
+        if self.path.is_empty() {
+            self.path = vec![ ".".to_owned() ];
         }
 
-        this
+        self
     }
 
     pub fn should_exclude(&self, path: &Path, file: &Metadata) -> bool {
@@ -186,12 +192,16 @@ impl Args {
         self.unit
     }
 
-    pub fn iter(&self) -> Iter<'_, String> {
-        self.path.iter()
+    pub const fn quiet(&self) -> bool {
+        self.quiet
+    }
+    
+    pub const fn threads(&self) -> usize {
+        self.threads
     }
 
-    pub fn quiet(&self) -> bool {
-        self.quiet
+    pub fn paths(&self) -> Iter<'_, String> {
+        self.path.iter()
     }
 }