tr-lazy-example.js

firstName$ = createCaller()
lastName$ = createCaller()
// not lazy
fullName$ = combine(
  [firstName$, lastName$],
  (_, fn, ln) => [fn, ln].join(' ')
);
displayName$ = combine(
  [firstName$, fullName$],
  (_, firstN, fullN) => firstN.length < 10 ? fullN : firstN
);
// lazy
isNameHuge = combine([firstName$], (_, fn) => fn.length > 10)
fullName$ = combine(
  [isNameHuge$, firstName$, lastName$],
  (_, lazy, firstName, lastName) => !lazy && [firstName, lastName].join(' ')
);
displayName$ = combine(
  [isNameHuge$, firstName$, fullName$],
  (_, isNameHuge, firstName, lastName) => isNameHuge ? firstName : lastName
);