Add SQL-style operators (#1322)

tests/jq.test

@@ -1322,3 +1322,32 @@ jq: error: syntax error, unexpected INVALID_CHARACTER, expecting $end (Unix shel
 (.[{}] = 0)?
 null
 
+INDEX(range(5)|[., "foo\(.)"]; .[0])
+null
+{"0":[0,"foo0"],"1":[1,"foo1"],"2":[2,"foo2"],"3":[3,"foo3"],"4":[4,"foo4"]}
+
+JOIN({"0":[0,"abc"],"1":[1,"bcd"],"2":[2,"def"],"3":[3,"efg"],"4":[4,"fgh"]}; .[0]|tostring)
+[[5,"foo"],[3,"bar"],[1,"foobar"]]
+[[[5,"foo"],null],[[3,"bar"],[3,"efg"]],[[1,"foobar"],[1,"bcd"]]]
+
+range(5;10)|IN(range(10))
+null
+true
+true
+true
+true
+true
+
+range(10;12)|IN(range(10))
+null
+false
+false
+
+IN(range(10;20); range(10))
+null
+false
+
+IN(range(5;20); range(10))
+null
+true
+