Distinguish MultipleStarArgs and InvalidStarArgs compile errors

Author: youknowone

compiler/src/compile.rs

@@ -1374,7 +1374,7 @@ impl<O: OutputStream> Compiler<O> {
                 for (i, element) in elements.iter().enumerate() {
                     if let ast::ExpressionType::Starred { .. } = &element.node {
                         if seen_star {
-                            return Err(self.error(CompileErrorType::StarArgs));
+                            return Err(self.error(CompileErrorType::MultipleStarArgs));
                         } else {
                             seen_star = true;
                             self.emit(Instruction::UnpackEx {
@@ -1782,11 +1782,7 @@ impl<O: OutputStream> Compiler<O> {
                 self.compile_comprehension(kind, generators)?;
             }
             Starred { .. } => {
-                return Err(
-                    self.error(CompileErrorType::SyntaxError(std::string::String::from(
-                        "Invalid starred expression",
-                    ))),
-                );
+                return Err(self.error(CompileErrorType::InvalidStarExpr));
             }
             IfExpression { test, body, orelse } => {
                 let no_label = self.new_label();

compiler/src/error.rs

@@ -47,7 +47,9 @@ pub enum CompileErrorType {
     Parse(ParseErrorType),
     SyntaxError(String),
     /// Multiple `*` detected
-    StarArgs,
+    MultipleStarArgs,
+    /// Misplaced `*` expression
+    InvalidStarExpr,
     /// Break statement outside of loop.
     InvalidBreak,
     /// Continue statement outside of loop.
@@ -97,7 +99,10 @@ impl fmt::Display for CompileError {
             CompileErrorType::ExpectExpr => "Expecting expression, got statement".to_owned(),
             CompileErrorType::Parse(err) => err.to_string(),
             CompileErrorType::SyntaxError(err) => err.to_string(),
-            CompileErrorType::StarArgs => "Two starred expressions in assignment".to_owned(),
+            CompileErrorType::MultipleStarArgs => {
+                "two starred expressions in assignment".to_owned()
+            }
+            CompileErrorType::InvalidStarExpr => "can't use starred expression here".to_owned(),
             CompileErrorType::InvalidBreak => "'break' outside loop".to_owned(),
             CompileErrorType::InvalidContinue => "'continue' outside loop".to_owned(),
             CompileErrorType::InvalidReturn => "'return' outside function".to_owned(),