gistfile1.txt

def = function(self) function(fName)
  let(_definition = [
      // Static
      op("new", function()
        def([])
      ),      
      // Access
      op("get", function(name) function(default = undef)
        safeGet(self, name, default)
      ),
      op("toString", function()
        doPrint() (self)
      ),
      // Mutation
      op("set", function(name)
        def(set(self, name))
      ),      
      op("add", function(a)
        let(b = safeGet(self, "sum", 0),
        ) def(set(self, field("sum", a+b)))
      ),
      op("test", function(a, b)
        let(s = safeGet(self, "sum", 0),
        ) def(set(self, field("sum", s+a+b)))
      ),    
    ],
  ) get(_definition, fName)
;

function call(fName) = 
  let(unset=function() undef
  ) function(a=unset, b=unset, c=unset, d=unset, e=unset, f=unset)
      let(params = filter([a, b, c, d, e, f], function(p) p != unset),
          map = [
            function(f) f(fName) (),
            function(f) f(fName) (params[0]),
            function(f) f(fName) (params[0], params[1]),
            function(f) f(fName) (params[0], params[1], params[2]),
            function(f) f(fName) (params[0], params[1], params[2], params[3]),
            function(f) f(fName) (params[0], params[1], params[2], params[3], params[4]),
            function(f) f(fName) (params[0], params[1], params[2], params[3], params[4], params[5]),
          ],
      ) map[len(params)]
;

echo(
  compose([
    call ("toString") (),
    function(f) foldl([1,2,3], function(a, g) g ("test") (1, a), f),
    call("test") (1, 1),
    call("add") (1),
    call("add") (1),
    call("new") ()
  ]) (def())
);

Replacement of the inline foldl

function flatCall(fName) = 
  let(unset=function() undef
  ) function(a=unset, b=unset, c=unset, d=unset, e=unset)
      let(params = filter([a, b, c, d, e], function(p) p != unset),
          map = [
            function(a) call(fName) (a),
            function(a) call(fName) (params[0], a),
            function(a) call(fName) (params[0], params[1], a),
            function(a) call(fName) (params[0], params[1], params[2], a),
            function(a) call(fName) (params[0], params[1], params[2], params[3], a),
            function(a) call(fName) (params[0], params[1], params[2], params[3], params[4], a),
          ],
      ) function(v) function(f) foldl(v, function(a, g) map[len(params)](a)(g), f)
;