map_tree: Map a function over the 'Node's in a 'Tree'

In russHyde/s3tree:

Description

This function allows you to map a function over the nodes in a tree. If the argument '.field' is 'NULL', a list of results is returned, otherwise, the results for a given node is added to a field of that name.

Usage

map_tree(.x, .f, ..., .field = NULL)

Arguments

.x	The 'Tree'
.f	The function to be applied to the 'Node's in the 'Tree'. If .f has an argument called '.tree' then 'map_tree' will pass the 'Tree' '.x' in as that argument automatically.
...	Further arguments to be passed into the function '.f'. Except: if the function '.f' takes an argument '.tree', then '.x' is passed in as the '.tree' argument automatically.
.field	If a string is provided, the values of '.f' will be appended to the respective 'Node's in the 'Tree'; '.field' gives the name of the field where this result is stored. If '.field' is 'NULL' (as default) a named 'list' of the results will be returned (names being the name of the relevant 'Node').

Details

If the function '.f' has an argument named 'tree', then '.f' can use details of the whole tree when evaluating the result for a given node. For example, when evaluating a given node, you can extract values from it's parent or children.

The tree is evaluated top-down, so children are evaluated after their parents.

If '.field' is non-'NULL', then the tree is modified as each node is evaluated. This means you can use the computed value for a parent when evaluating for a child.

The tree is not currently modified when '.field' is non-null.

russHyde/s3tree documentation built on May 16, 2019, 5:03 a.m.