fix: when formatting and add some methods to Project::Error

crates/cli/src/cmd/fmt.rs

@@ -24,7 +24,7 @@ pub fn exec(
     if let Err(err) = aiken_project::format::run(stdin, check, files) {
         err.report();
 
-        miette::bail!("failed: {} error(s)", err.total());
+        miette::bail!("failed: {} error(s)", err.len());
     };
 
     Ok(())

crates/cli/src/lib.rs

@@ -30,10 +30,7 @@ where
     if let Err(err) = build_result {
         err.report();
 
-        miette::bail!(
-            "failed: {} error(s), {warning_count} warning(s)",
-            err.total(),
-        );
+        miette::bail!("failed: {} error(s), {warning_count} warning(s)", err.len(),);
     };
 
     println!("finished with {warning_count} warning(s)");

crates/lang/src/format.rs

@@ -165,9 +165,9 @@ impl<'comments> Formatter<'comments> {
     }
 
     fn module<'a>(&mut self, module: &'a UntypedModule) -> Document<'a> {
-        let groups = self.definitions(&module.definitions);
+        let defs = self.definitions(&module.definitions);
 
-        // Now that `groups` has been collected, only freestanding comments (//)
+        // Now that `defs` has been collected, only freestanding comments (//)
         // and doc comments (///) remain. Freestanding comments aren't associated
         // with any statement, and are moved to the bottom of the module.
         let doc_comments = join(
@@ -196,7 +196,7 @@ impl<'comments> Formatter<'comments> {
             nil()
         };
 
-        let non_empty = vec![module_comments, groups, doc_comments, comments]
+        let non_empty = vec![module_comments, defs, doc_comments, comments]
             .into_iter()
             .filter(|doc| !doc.is_empty());
 
@@ -753,10 +753,9 @@ impl<'comments> Formatter<'comments> {
                 subjects.iter().map(|s| self.wrap_expr(s)),
                 break_(",", ", "),
             ))
-            .append(break_(" is", " is "))
             .nest(INDENT)
             .append(break_("", " "))
-            .append("{")
+            .append("is {")
             .group();
 
         let clauses_doc = concat(

crates/lang/src/parser.rs

@@ -226,6 +226,7 @@ pub fn fn_parser() -> impl Parser<Token, ast::UntypedDefinition, Error = ParseEr
         .then(
             fn_param_parser()
                 .separated_by(just(Token::Comma))
+                .allow_trailing()
                 .delimited_by(just(Token::LeftParen), just(Token::RightParen))
                 .map_with_span(|arguments, span| (arguments, span)),
         )

crates/project/src/error.rs

@@ -53,7 +53,7 @@ pub enum Error {
 }
 
 impl Error {
-    pub fn total(&self) -> usize {
+    pub fn len(&self) -> usize {
         match self {
             Error::List(errors) => errors.len(),
             _ => 1,
@@ -84,6 +84,33 @@ impl Error {
 
         Error::List(errors)
     }
+
+    pub fn append(self, next: Self) -> Self {
+        match (self, next) {
+            (Error::List(mut errors), Error::List(mut next_errors)) => {
+                errors.append(&mut next_errors);
+
+                Error::List(errors)
+            }
+            (Error::List(mut errors), rest) => {
+                errors.push(rest);
+
+                Error::List(errors)
+            }
+            (rest, Error::List(mut next_errors)) => {
+                let mut errors = vec![rest];
+
+                errors.append(&mut next_errors);
+
+                Error::List(errors)
+            }
+            (error, next_error) => Error::List(vec![error, next_error]),
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        matches!(self, Error::List(errors) if errors.is_empty())
+    }
 }
 
 impl Debug for Error {

crates/project/src/format.rs

@@ -77,7 +77,7 @@ fn format_files(files: Vec<String>) -> Result<(), Error> {
 
 fn unformatted_files(files: Vec<String>) -> Result<Vec<Unformatted>, Error> {
     let mut problem_files = Vec::with_capacity(files.len());
-    let mut errors = Vec::new();
+    let mut errors = Error::List(vec![]);
 
     for file_path in files {
         let path = PathBuf::from_str(&file_path).unwrap();
@@ -85,19 +85,18 @@ fn unformatted_files(files: Vec<String>) -> Result<Vec<Unformatted>, Error> {
         if path.is_dir() {
             for path in aiken_files_excluding_gitignore(&path) {
                 if let Err(err) = format_file(&mut problem_files, path) {
-                    errors.push(err);
+                    errors = errors.append(err);
                 };
             }
         } else if let Err(err) = format_file(&mut problem_files, path) {
-            println!("{:?}", err);
-            errors.push(err);
+            errors = errors.append(err);
         }
     }
 
     if errors.is_empty() {
         Ok(problem_files)
     } else {
-        Err(Error::List(errors))
+        Err(errors)
     }
 }
 

examples/sample/src/scripts/swap.ak

@@ -9,7 +9,7 @@ pub type Redeemer {
 }
 
 pub fn spend(datum: Datum, rdmr: Redeemer, ctx: spend.ScriptContext) -> Bool {
-  when rdmr is  {
+  when rdmr is {
     Buy -> True
     Sell -> datum.something == "Aiken"
   }