fix prefix

scout-interpreter/src/lib.rs

@@ -577,7 +577,7 @@ fn eval_expression<'a>(
             ExprKind::Infix(lhs, op, rhs) => {
                 let l_obj = eval_expression(lhs, crawler, env.clone(), results.clone()).await?;
                 let r_obj = eval_expression(rhs, crawler, env.clone(), results.clone()).await?;
-                let res = eval_op(l_obj.clone(), op, r_obj.clone())?;
+                let res = eval_infix(l_obj.clone(), op, r_obj.clone())?;
                 Ok(res)
             }
             ExprKind::Boolean(val) => Ok(Arc::new(Object::Boolean(*val))),
@@ -601,7 +601,7 @@ fn eval_expression<'a>(
     .boxed()
 }
 
-fn eval_op(lhs: Arc<Object>, op: &TokenKind, rhs: Arc<Object>) -> EvalResult {
+fn eval_infix(lhs: Arc<Object>, op: &TokenKind, rhs: Arc<Object>) -> EvalResult {
     match op {
         TokenKind::EQ => Ok(Arc::new(Object::Boolean(lhs == rhs))),
         TokenKind::NEQ => Ok(Arc::new(Object::Boolean(lhs != rhs))),

scout-parser/src/lib.rs

@@ -60,6 +60,7 @@ fn map_prefix_fn(kind: &TokenKind) -> Option<PrefixParseFn> {
         LBracket => Some(Parser::parse_list_literal),
         SelectAll => Some(Parser::parse_select_all),
         Select => Some(Parser::parse_select),
+        Bang => Some(Parser::parse_prefix),
         _ => None,
     }
 }
@@ -270,6 +271,13 @@ impl Parser {
         Ok(IfLiteral { cond, block })
     }
 
+    fn parse_prefix(&mut self) -> ParseResult<ExprKind> {
+        let op = self.curr.kind;
+        self.next_token();
+        let expr = self.parse_expr(Precedence::Lowest)?;
+        Ok(ExprKind::Prefix(Box::new(expr), op))
+    }
+
     fn parse_block(&mut self, finalizers: Vec<TokenKind>) -> ParseResult<Block> {
         let mut stmts = Vec::new();
         while !finalizers.contains(&self.curr.kind) {
@@ -753,6 +761,10 @@ mod tests {
             )
         ); "crawl stmt with bindings"
     )]
+    #[test_case(
+        "!true",
+        StmtKind::Expr(ExprKind::Prefix(Box::new(ExprKind::Boolean(true)), TokenKind::Bang,)); "bang prefix"
+    )]
     fn test_single_stmt(input: &str, exp: StmtKind) {
         let stmt = extract_first_stmt(input);
         assert_eq!(stmt, exp);