fix parser to match abnf conditional

grammar/abnf-grammar.txt

@@ -453,7 +453,7 @@ identifier = letter *( letter / digit / "_" )   ; but not a keyword or aleo1...
 ; A package name consists of one or more segments separated by single dashes,
 ; where each segment is a non-empty sequence of lowercase letters and digits.
 
-package-name = 1*( lowercase-letter / digit )
+package-name = 1*lowercase-letter
                *( "-" 1*( lowercase-letter / digit ) )
 
 ; Annotations have names, which are identifiers immediately preceded by `@`.
@@ -962,7 +962,7 @@ assert-call = %s"assert" "(" expression ")"
 
 print-function = %s"debug" / %s"error" / %s"log"
 
-print-arguments = "(" [ string-literal *( "," expression ) ] ")"
+print-arguments = "(" string-literal  *( "," expression ) ")"
 
 print-call = print-function print-arguments
 
@@ -1020,7 +1020,7 @@ member-function-declaration = function-declaration
 ; this may be relaxed after the backward compatibility is removed,
 ; allowing member variables and member functions to be intermixed.
 
-circuit-declaration = *annotation %s"circuit" identifier
+circuit-declaration = %s"circuit" identifier
                       "{" [ member-variable-declarations ]
                       *member-function-declaration "}"
 

parser/src/errors/syntax.rs

@@ -100,6 +100,10 @@ impl SyntaxError {
         )
     }
 
+    pub fn unexpected_statement(got: String, expected: &str, span: &Span) -> Self {
+        Self::new_from_span(format!("expected '{}', got '{}'", expected, got.to_string()), span)
+    }
+
     pub fn unexpected_str(got: &Token, expected: &str, span: &Span) -> Self {
         Self::new_from_span(format!("expected '{}', got '{}'", expected, got.to_string()), span)
     }

parser/src/parser/file.rs

@@ -102,11 +102,20 @@ impl ParserContext {
         let end_span;
         let arguments = if self.eat(Token::LeftParen).is_some() {
             let mut args = Vec::new();
+            let mut comma = false;
             loop {
                 if let Some(end) = self.eat(Token::RightParen) {
+                    if comma {
+                        return Err(SyntaxError::unexpected(
+                            &Token::RightParen,
+                            &[Token::Ident("identifier".into()), Token::Int("number".into())],
+                            &end.span,
+                        ));
+                    }
                     end_span = end.span;
                     break;
                 }
+                comma = false;
                 if let Some(ident) = self.eat_identifier() {
                     args.push(ident.name);
                 } else if let Some((int, _)) = self.eat_int() {
@@ -115,10 +124,11 @@ impl ParserContext {
                     let token = self.peek()?;
                     return Err(SyntaxError::unexpected_str(&token.token, "ident or int", &token.span));
                 }
-                if self.eat(Token::Comma).is_none() {
+                if self.eat(Token::Comma).is_none() && !comma {
                     end_span = self.expect(Token::RightParen)?;
                     break;
                 }
+                comma = true;
             }
             args
         } else {

parser/src/parser/statement.rs

@@ -185,7 +185,17 @@ impl ParserContext {
         self.fuzzy_struct_state = false;
         let body = self.parse_block()?;
         let next = if self.eat(Token::Else).is_some() {
-            Some(Box::new(self.parse_statement()?))
+            let s = self.parse_statement()?;
+            match s {
+                Statement::Block(_) | Statement::Conditional(_) => Some(Box::new(s)),
+                s => {
+                    return Err(SyntaxError::unexpected_statement(
+                        s.to_string(),
+                        "Block or Conditional",
+                        s.span(),
+                    ));
+                }
+            }
         } else {
             None
         };

tests/expectations/parser/parser/functions/annotated_fail.leo.out

@@ -0,0 +1,5 @@
+---
+namespace: Parse
+expectation: Fail
+outputs:
+  - "    --> test:3:12\n     |\n   3 | @test(test,)\n     |            ^\n     |\n     = expected 'identifier', 'number' -- got ')'"

tests/expectations/parser/parser/import/invalid.leo.out

@@ -0,0 +1,5 @@
+---
+namespace: Parse
+expectation: Fail
+outputs:
+  - "    --> test:3:18\n     |\n   3 | import foo as bar;\n     |                  ^\n     |\n     = expected '.' -- got ';'"

tests/parser/functions/annotated_fail.leo

@@ -0,0 +1,9 @@
+/*
+namespace: Parse
+expectation: Fail
+*/
+
+@test(test,)
+function x() {
+    return ();
+}

tests/parser/import/invalid.leo

@@ -0,0 +1,7 @@
+/*
+namespace: Parse
+expectation: Fail
+*/
+
+import foo as bar;
+import *;