Passing named arguments using assigned objects

[dchiu911]

I can't seem to pass named arguments to glue when the values are assigned to objects with the same name as the interpolations:

# Example from ?glue
glue('My name is {name},',
     ' my age next year is {age + 1},',
     ' my anniversary is {format(anniversary, "%A, %B %d, %Y")}.',
     name = "Joe",
     age = 40,
     anniversary = as.Date("2001-10-12"))
# My name is Joe, my age next year is 41, my anniversary is Friday, October 12, 2001.

# Passing named arguments using different names
nm <- "Joe"
ag <- 40
an <- as.Date("2001-10-12")
glue('My name is {name},',
     ' my age next year is {age + 1},',
     ' my anniversary is {format(anniversary, "%A, %B %d, %Y")}.',
     name = nm,
     age = ag,
     anniversary = an)
# My name is Joe, my age next year is 41, my anniversary is Friday, October 12, 2001.

# Passing named arguments using same names
name <- "Joe"
age <- 40
anniversary <- as.Date("2001-10-12")
glue('My name is {name},',
     ' my age next year is {age + 1},',
     ' my anniversary is {format(anniversary, "%A, %B %d, %Y")}.',
     name = name,
     age = age,
     anniversary = anniversary)
# Error in eval(parse(text = text, keep.source = FALSE), envir) : 
#   promise already under evaluation: recursive default argument reference or earlier problems?

[egnha]

Thanks for catching this! Invariably, the error ”promise already under evaluation” means that a promise is stepping on its toes, i.e., trying to resolve to itself, e.g., (function(x = x) x)(). I've proposed a fix in #90, by staggering the promises.

[jimhester]

I don't think this is a problem, you don't need to use named arguments if the name is identical, you just omit them entirely.

[egnha]

@jimhester Good point about the example. Do you think something like glue(“Date: {date}”, date = localize_date(date)) ought to work, where date is in the current env? (#90 would enable this.)

[jimhester]

@egnha, that is a good point

x <- 1
glue::glue("{x}", x = x + 1)

Should definitely work, and currently does not, so we will need to do something like #90.