Allow negated object values without parens. Fixes #247

parser.y

@@ -458,7 +458,9 @@ ExpD:
 ExpD '|' ExpD { 
   $$ = block_join($1, $3);
 } |
-
+'-' ExpD {
+  $$ = BLOCK($2, gen_call("_negate", gen_noop()));
+} |
 Term {
   $$ = $1;
 }

tests/all.test

@@ -36,6 +36,10 @@ null
 null
 []
 
+{x: -1}
+null
+{"x": -1}
+
 # The input line starts with a 0xFEFF (byte order mark) codepoint
 # No, there is no reason to have a byte order mark in UTF8 text.
 # But apparently people do, so jq shouldn't break on it.