expr_print {rlang}R Documentation

Print an expression

Description

expr_print(), powered by expr_deparse(), is an alternative printer for R expressions with a few improvements over the base R printer.

Usage

expr_print(x, width = peek_option("width"))

expr_deparse(x, width = peek_option("width"))

Arguments

x

An object or expression to print.

width

The width of the deparsed or printed expression. Defaults to the global option width.

Examples

# It supports any object. Non-symbolic objects are always printed
# within angular brackets:
expr_print(1:3)
expr_print(function() NULL)

# Contrast this to how the code to create these objects is printed:
expr_print(quote(1:3))
expr_print(quote(function() NULL))

# The main cause of non-symbolic objects in expressions is
# quasiquotation:
expr_print(expr(foo(!!(1:3))))


# Quosures from the global environment are printed normally:
expr_print(quo(foo))
expr_print(quo(foo(!!quo(bar))))

# Quosures from local environments are colourised according to
# their environments (if you have crayon installed):
local_quo <- local(quo(foo))
expr_print(local_quo)

wrapper_quo <- local(quo(bar(!!local_quo, baz)))
expr_print(wrapper_quo)

[Package rlang version 0.2.2 Index]