withVisible

R Base 3.6.2

This function evaluates an expression, returning it in a two element list containing its value and a flag showing whether it would automatically print.

Syntax

withVisible(x)

Arguments

Parameter	Description
`x`	an expression to be evaluated.

Return Value

value The value of x after evaluation. visible logical; whether the value would auto-print.

Details

The argument, not an expression object, rather an (unevaluated function) call, is evaluated in the caller's context. This is a primitive function.

Examples

Example

# NOT RUN {
x <- 1
withVisible(x <- 1) # *$visible is FALSE
x
withVisible(x)      # *$visible is TRUE

# Wrap the call in evalq() for special handling

df <- data.frame(a = 1:5, b = 1:5)
evalq(withVisible(a + b), envir = df)
# }