Class LHoist

Object
   |
   +--Lens
         |
         +--LHoist

class LHoist

extends Lens

A primitive lens for working with objects; it will 'hoist' a property of a single property object, e.g.:

By Pierce and Foster's definition, hoist should only accept objects with a single property. For convenience, more objects with more than one property will be accepted by hoist; however, missing values will not be returned on putback. If missing values should be restored on putback, use LFocus.

Hoist will also (non-standardly) accept objects on get without the desired property; undefined will be returned.

- LHoistNonunique

Field Detail

name

Object name

LHoist

LHoist(<String> prop, <boolean> check_prop)

Parameters:
prop - The property of the concrete tree to select for. It must have only one property. For a more permissive form of hoisting, see LFocus.
check_prop - Whether or not to check that the property prop is really present and the only property. If it is not, an error will be signalled. This is false by default.

See:
- LHoistNonunique

get

Object get(c)

putback

Object putback(a, c)