9 Dict lenses

6.2.901.900

9 Dict lenses

procedure
(dict-ref-lens key) → lens?
key : any/c

Returns a lens for viewing the value mapped to key in a dict.

Examples:

> (define dict '((a . 1) (b . 2) (c . 3)))
> (lens-view (dict-ref-lens 'a) dict)
1
> (lens-set (dict-ref-lens 'a) dict 100)
'((a . 100) (b . 2) (c . 3))

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1	Core Lens Forms
2	Joining and Composing Lenses
3	Pair and List Lenses
4	Hash Lenses
5	Struct Lenses
6	Vector lenses
7	String Lenses
8	Stream Lenses
9	Dict lenses
10	Applicable lenses