map_l

This lens allows you to access and modify elements of a list or vector
based on their position or a logical condition.

Provides utilities to create and use lenses to simplify data
manipulation. Lenses are composable getter/setter pairs that provide a
functional approach to manipulating deeply nested data structures, e.g.,
elements within list columns in data frames. The implementation is based on
the earlier 'lenses' R package <https://github.com/cfhammill/lenses>,
which was inspired by the Haskell 'lens' package by Kmett (2012)
<https://github.com/ekmett/lens>, one of the most widely referenced
implementations of lenses. For additional background and history on the
theory of lenses, see the 'lens' package wiki:
<https://github.com/ekmett/lens/wiki/History-of-Lenses>.

Albert Wang

tinylens

Minimal Implementation of Functional Lenses

map_l function

<dl><dt>l</dt>
<dd>A lens that selects the elements to lens into</dd>
<dt>.ptype</dt>
<dd>The prototype of the data structure to return</dd></dl>

Arguments

Lens into a list or vector — map_l

<dl>

<dt>l</dt>
<dd>A lens that selects the elements to lens into</dd>


<dt>.ptype</dt>
<dd>The prototype of the data structure to return</dd>

</dl>

map_l: Lens into a list or vector

Description

Usage

Value

Arguments

Examples