mvbutils (version 1.1.1)

cdfind: Hierarchy-crawling functions for cd-organized workspaces

Description

These functions work through part or all of a workspace (task) hierarchy set up via cd. cdfind searches for objects through the (attached and unattached) task hierarchy. cdtree displays the hierarchy structure. cd.change.all.paths is useful for moving or migrating all or part of the hierarchy to new disk directories. cd.write.mvb.tasks sets up sourceable text representations of the hierarchy, as a safeguard. cditerate is the engine that crawls through the hierarchy, underpinning the others; you can write your own functions to be called by cditerate.

Usage

cdfind( pattern, from = ., from.text)
cdtree( from = ., from.text = substitute(from), charlim = 90)
cd.change.all.paths( from.text = "0", old.path, new.path)
cd.write.mvb.tasks( from = ., from.text = substitute(from))
cditerate( from.text, what.to.do, so.far = vector("NULL", 0), ...)

Arguments

pattern

regexpr to be checked against object names.

from

unquoted path specifier (see cd); make this 0 to operate on the entire hierarchy.

from.text

use this in place of from if you want to use a character string instead

charlim

maximum characters per line allowed in graphical display of cdtree; reduce if unreadable, or change par( cex)

old.path

regexpr showing portion of directory names to be replaced

new.path

replacement portion of directory names

what.to.do

function to be called on each task (see DETAILS)

so.far

starting value for accumulated list of function results

...

further fixed arguments to be passed to what.to.do

Value

• cdfind returns a list with one element for each object that is found somewhere; each such element is a character vector showing the tasks where the object was found. cdtree returns an object of class cdtree, which is normally printed with indentations to show the hierarchy. You can also plot(cdtree(...)) to see a graphical display. cd.change.all.paths and cd.write.mvb.tasks do not return anything useful.

Details

All these functions start by default from the task that is currently top of the search list, and only look further down the hiearchy (i.e. to unattached descendents). To make them work through the whole hierarchy, supply 0 as the from argument. If you want to automatically crawl through the task hierarchy to do something else, you can write a wrapper function which calls cditerate, and an inner function to be passed as the what.to.do argument to cditerate. The wrapper function will typically be very short; see the code of cdfind for an example. The inner function (typically called cdsomething.guts) must have arguments found, task.dir, task.name, and env, and may have any other arguments, which will be set according as the ... argument of cditerate. found accumulates the results of previous calls to what.to.do. Your inner function can augment found, and should return the (possibly augmented) found. As for the other parameters: task.dir is obvious; task.name is a character(1) giving the full path specifier, e.g. "ROOT/mytask"; and env holds the environment into which the task has been (temporarily) loaded. env allows you to examine the task; for instance, you can check objects in the task by calling ls(env=env) inside your what.to.do function. See the code of cdfind.guts for an example.

Examples

cdfind( ".First", 0) # probably returns list( .First="ROOT")}
<keyword>utilities</keyword>