Add record literal syntax (#326)

crates/nu-engine/src/eval.rs

@@ -297,6 +297,20 @@ pub fn eval_expression(
                 span: expr.span,
             })
         }
+        Expr::Record(fields) => {
+            let mut cols = vec![];
+            let mut vals = vec![];
+            for (col, val) in fields {
+                cols.push(eval_expression(engine_state, stack, col)?.as_string()?);
+                vals.push(eval_expression(engine_state, stack, val)?);
+            }
+
+            Ok(Value::Record {
+                cols,
+                vals,
+                span: expr.span,
+            })
+        }
         Expr::Table(headers, vals) => {
             let mut output_headers = vec![];
             for expr in headers {