How do I import functions from a package using a variable name in import?

Use the .character_only=TRUE parameter. For example, if pkg <- 'dplyr', call import::from(pkg, select, .character_only=TRUE). This forces import to treat the package name as a character string instead of a symbol, enabling programmatic imports.

What's better for avoiding namespace conflicts: import or the conflicted package?

import focuses on precise, selective importing and renaming, while conflicted makes conflicting functions throw errors to force explicit resolution. Choose import if you want control over what's imported; use conflicted for a stricter, error-driven approach in collaborative projects.

Can I use import in R package development?

Yes, but with caution. You can use import to manage dependencies without exposing all functions, but it must be listed in Imports or Depends. Some CRAN guidelines may prefer base R methods, so check package policies to avoid issues.

How to import the %>% operator from magrittr with import?

Operators must be quoted in import calls. For example, use import::from(magrittr, '%>%', '%$%', .into='operators'). This places the operators in a custom search path entity, keeping them accessible without cluttering the global namespace.

Does import add performance overhead compared to library()?

Import can have minor overhead because it creates separate entities in the search path and processes imports dynamically. However, for most use cases, the impact is negligible, and the benefits of reduced namespace conflicts often outweigh performance concerns.

How do I remove imported functions after using import?

Imported functions are placed in the search path (e.g., in an 'imports' entity). To remove them, detach the entity using detach('imports') or restart your R session. Import doesn't provide a built-in cleanup function, so manual management is required.

What happens if I import a function that masks an existing one without renaming?

The imported function will mask the existing one based on search path order, potentially causing unexpected behavior. Always use renaming (e.g., keep_when = filter) or check conflicts with import::what() to avoid issues in your code.

Open-Awesome

import

Q: What's better for avoiding namespace conflicts: import or the conflicted package?

import focuses on precise, selective importing and renaming, while conflicted makes conflicting functions throw errors to force explicit resolution. Choose import if you want control over what's imported; use conflicted for a stricter, error-driven approach in collaborative projects.

Q: Can I use import in R package development?

Yes, but with caution. You can use import to manage dependencies without exposing all functions, but it must be listed in Imports or Depends. Some CRAN guidelines may prefer base R methods, so check package policies to avoid issues.

NOASSERTIONRv1.3.2

An R package providing a selective import mechanism for functions from packages and modules, avoiding namespace pollution.

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What is import?

import is an R package that provides a selective import mechanism for functions from external packages and custom R module scripts. It solves the problem of namespace pollution and masking conflicts that occur when loading entire packages with `library()`, allowing developers to import only the specific functions they need.

Target Audience

R developers and data scientists who work with multiple packages and want to avoid namespace conflicts, improve code clarity, and adopt modular programming practices in their scripts and projects.

Value Proposition

Developers choose import over base R's `library()` because it offers precise control over function imports, prevents naming conflicts, supports custom modules, and integrates seamlessly into existing workflows without requiring major changes to code structure.

Overview

An Import Mechanism For R

Use Cases

Best For

Avoiding namespace conflicts when using functions with common names from different packages
Importing only specific functions from large packages to reduce memory footprint
Creating modular R scripts that reuse functions from custom .R files
Improving code readability by making function origins explicit
Managing dependencies in R packages without exposing internal imports
Renaming imported functions to fit project naming conventions

Not Ideal For

Projects that prioritize minimal external dependencies and can rely solely on base R's new include.only/exclude features in library()
Scripts requiring frequent programmatic or dynamic imports where .character_only parameter adds unnecessary boilerplate
Teams already standardized on the conflicted package for a different, error-driven approach to namespace conflicts
Environments where simplicity and immediate readability are paramount, and the extra syntax of import::from() outweighs benefits

Pros & Cons

Pros

Selective Namespace Control

Allows importing only specific functions from packages, preventing masking conflicts and reducing memory overhead, as demonstrated by importing just impute() and nomiss() from Hmisc instead of all 400+ functions.

Custom Module Support

Enables importing functions from external R script files (modules), facilitating code modularity and reuse, shown with examples like sequence_module.R for mathematical functions.

Flexible Function Renaming

Easy aliasing of functions to avoid naming clashes, such as renaming dplyr's filter to keep_when, improving code clarity without altering logic.

Advanced Import Parameters

Offers fine-grained control with .all, .except, .into, and .character_only for complex scenarios, like grouping imports into custom search path entities or handling variable names.

Cons

Redundancy with Base R

Base R's library() now includes include.only and exclude arguments for selective imports, making import less essential for basic use cases, as noted in the 'See also' section.

Cumbersome Dynamic Imports

Requires .character_only=TRUE for importing from variable names (e.g., module_name), adding an extra step and complexity compared to symbolic evaluation, which can be error-prone.

Potential Breaking Changes

Default behavior has shifted, such as the .library parameter changing from using only the first library path to all paths in version 1.3.0, which could disrupt existing workflows without clear migration paths.

Frequently Asked Questions

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