bind-late

bind-late

Late binding of overridable object properties.

Description

Define an overridable object where special "late binded" functions will be treated as lazy memoized properties.

All the functions in the object structure that are anonymous and take a single _ argument, are considered to be "late bindings". When the property is accessed the first time, they are called with the final overridden object as _ parameter, and their return value is affected to the property.

Example

const bindLate = require('bind-late')

const a = bindLate({
  a: 8,
  b: {
    c: 2,
    d: _ => _.a + _.b.c,
  },
  e: _ => _.b.d * 2,
})

a.b.d === 10 // 8 + 2
a.e === 20 // 10 * 2

const b = a.override({ a: 6 })

b.b.d === 8 // 6 + 2
b.e === 16 // 8 * 2

const c = b.override({
  b: { c: 6 },
  e: _ => _.b.d - 2,
})

c.b.d === 12 // 6 + 6
c.e === 10 // 12 - 2