7 String Lenses

6.2.901.900

procedure
(string-ref-lens i) → lens?
i : exact-nonnegative-integer?

Returns a lens for viewing the ith character of a string.

Examples:

> (lens-view (string-ref-lens 2) "abcdef")
#\c
> (lens-set (string-ref-lens 2) "abcdef" #\C)
"abCdef"

procedure
(string-pick-lens i) → lens?
i : exact-nonnegative-integer?

Examples:

> (define 1-5-6-lens (string-pick-lens 1 5 6))
> (lens-view 1-5-6-lens "abcdefg")
"bfg"
> (lens-set 1-5-6-lens "abcdefg" "BFG")
"aBcdeFG"

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