r-cli

CLI for R Packages

When to Use What

task: Display error with context and formatting use: cli_abort() with inline markup and bullet lists

task: Show warning with formatting use: cli_warn() with inline markup

task: Display informative message use: cli_inform() with inline markup

task: Show progress for counted operations use: cli_progress_bar() with total count

task: Show simple progress steps use: cli_progress_step() with status messages

task: Format code or function names use: {.code ...} or {.fn package::function}

task: Format file paths use: {.file path/to/file}

task: Format package names use: {.pkg packagename}

task: Format variable names use: {.var variable_name}

task: Format values use: {.val value}

task: Handle singular/plural text use: {?s} or {?y/ies} with pluralization

task: Create headers use: cli_h1(), cli_h2(), cli_h3()

task: Create alerts use: cli_alert_success(), cli_alert_danger(), cli_alert_warning(), cli_alert_info()

task: Create lists use: cli_ul(), cli_ol(), cli_dl() with cli_li()

Inline Markup Essentials

Use inline markup with {.class content} syntax to format text:

# Basic formatting
cli_text("Function {.fn mean} calculates averages")
cli_text("Install package {.pkg dplyr}")
cli_text("See file {.file ~/.Rprofile}")
cli_text("{.var x} must be numeric, not {.obj_type_of {x}}")
cli_text("Got value {.val {x}}")

# Code formatting
cli_text("Use {.code sum(x, na.rm = TRUE)}")

# Paths and arguments
cli_text("Reading from {.path /data/file.csv}")
cli_text("Set {.arg na.rm} to TRUE")

# Types and classes
cli_text("Object is {.cls data.frame}")

# Emphasis
cli_text("This is {.emph important}")
cli_text("This is {.strong critical}")

# Fields
cli_text("The {.field name} field is required")

Vector Collapsing

Vectors are automatically collapsed with commas and "and":

pkgs <- c("dplyr", "tidyr", "ggplot2")
cli_text("Installing packages: {.pkg {pkgs}}")
#> Installing packages: dplyr, tidyr, and ggplot2

files <- c("data.csv", "script.R")
cli_text("Found {length(files)} file{?s}: {.file {files}}")
#> Found 2 files: data.csv and script.R