// vars: input, _ (underscore.js) Object.prototype.pipe = function(f) { return f(this); } Object.prototype.mapValues = function(f) { return Object.fromEntries(Object.entries(this).map(([k, v]) => [k, f(v)])); } Object.prototype.filterValues = function(f) { return Object.fromEntries(Object.entries(this).filter(([k, v]) => f(v))); } return input