The help.import() function
finds the help file for functions or topics,
including exposed functions/operators as well as functions in a package alias object.
The is.tinyimport() function
checks if an alias object or an exposed function is of class tinyimport;
i.e. if it is an object produced by the
import_as, import_inops, or import_LL function.
The attr.import() function
gets one or all special attribute(s)
from an alias object returned by import_as.
Arguments
- ...
further arguments to be passed to help.
- i
either one of the following:
a function (use back-ticks when the function is an infix operator). Examples:
myfun,`%operator%`,myalias.$some_function. If a function, thealiasargument is ignored.a string giving the function name or topic (i.e.
"myfun","thistopic"). If a string, argumentaliasmust be specified also.
- alias
the alias object as created by the import_as function.
- x
an existing object (i.e. an assigned variable or a locked constant) to be tested.
- which
The attributes to list. If
NULL, all attributes will be returned.
Possibilities: "pkgs", "conflicts", "args", and "ordered_object_names".
Value
For help.import():
Opens the appropriate help page.
For is.tinyimport():
Returns TRUE if the function is produced by
import_as, import_inops, or import_LL,
and returns FALSE if it is not.
For attr.import(alias, which = NULL):
All special attributes of the given alias object are returned as a list.
For attr.import(alias, which = "pkgs"):
Returns a list with 3 elements:
packages_order: a character vector of package names, giving the packages in the order they were imported in the alias object.
main_package: a string giving the name of the main package. Re-exported functions, if present, are taken together with the main package.
re_exports.pkgs: a character vector of package names, giving the packages from which the re-exported functions in the main package were taken.
For attr.import(alias, which = "conflicts"):
The order in which packages are imported in the alias object
(see attribute pkgs$packages_order)
matters:
Functions from later named packages overwrite those from earlier named packages,
in case of conflicts.
The "conflicts" attribute returns a data.frame showing exactly which functions overwrite
functions from earlier named packages, and as such "win" the conflicts.
For attr.import(alias, which = "args"):
Returns a list of input arguments.
These were the arguments supplied to import_as when
the alias object in question was created.
For attr.import(alias, which = "ordered_object_names"):
Gives the names of the objects in the alias, in the order as they were imported.
For conflicting objects, the last imported ones are used for the ordering.
Note that if argument re_exports is TRUE,
re-exported functions are imported when the main package is imported,
thus changing this order slightly.
Details
For help.import(...):
Do not use the topic / package and
i / alias argument sets together.
It's either one set or the other.
For example:
import_as(~ mr., "magrittr")
import_inops(mr.)
help.import(i = mr.$add)
help.import(i = `%>%`)
help.import(i = "add", alias = mr.)
help.import(topic = "%>%", package = "magrittr")
help.import("%>%", package = "magrittr") # same as previous line
Examples
import_as(~ to., "tinycodet")
#> Importing packages and registering methods...
#> Done
#> You can now access the functions using `to.$`
#> For conflicts report, packages order, and other attributes, run `attr.import(to.)`
import_inops(to.)
#> Checking for conflicting infix operators in the current environment...
#> Placing infix operators in current environment...
#> Done
`%s==%` <- stringi::`%s==%`
is.tinyimport(to.) # returns TRUE
#> [1] TRUE
is.tinyimport(`%:=%`) # returns TRUE
#> [1] TRUE
is.tinyimport(`%s==%`) # returns FALSE: not imported by tinycodet import system
#> [1] FALSE
attr.import(to., which = "conflicts")
#> package winning_conflicts
#> 1 tinycodet + re-exports