existsMetaValue-character-environment-method: Check Existence of Meta Value (char-env)

Description Usage Arguments Value Author(s) References See Also Examples

Description

See generic: existsMetaValue

Usage

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## S4 method for signature 'character,environment'
existsMetaValue(id,
  where = tryCatch(devtools::as.package(".")$package, error = function(cond) {
      stop("Invalid default value for `where`") }), sub_id = character(),
  default = NULL, strict = c(0, 1, 2), ...)

Arguments

id

character.

where

environment.

sub_id

character. Optional ID for a sub layer. Useful for a hub-like option container structure.

default

ANY. Value to be returned if option does not exist. See getOption and getNested.

strict

logical. Controls what happens when id points to a non-existing meta object:

  • 0: ignore and return FALSE to signal that the assignment process was not successful or fail_value depending on the value of return_status

  • 1: ignore and with warning and return FALSE

  • 2: ignore and with error

...

Further arguments to be passed to subsequent functions/methods.

Value

See method existsMetaValue-char-char-method

Author(s)

Janko Thyson janko.thyson@gmail.com

References

http://github.com/Rappster/optionr

See Also

existsMetaValue

Examples

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## Not run: 

##------------------------------------------------------------------------------
## Basics //
##------------------------------------------------------------------------------

setMetaValue(id = "test", value = TRUE)
existsMetaValue(id = "test")

setMetaValue(id = "a/b/c", value = 10)
existsMetaValue(id = "a")
existsMetaValue(id = "a/b")
existsMetaValue(id = "a/b/c")
existsMetaValue(id = "a/b/c/d")

existsMetaValue(id = "c")
existsMetaValue(id = "c/d/e")
  
##------------------------------------------------------------------------------
## Strictness levels //
##------------------------------------------------------------------------------

## Empty ID //
existsMetaValue(id = character())
try(existsMetaValue(id = character(), strict = 1))
try(existsMetaValue(id = character(), strict = 2))

## Not-existing //  
existsMetaValue(id = "c/d/e")
try(existsMetaValue(id = "c/d/e", strict = 1))
try(existsMetaValue(id = "c/d/e", strict = 2))

##------------------------------------------------------------------------------
## Explicit `where` //
##------------------------------------------------------------------------------

where <- new.env()
setMetaValue(id = "a/b/c", value = 10, where = where)
existsMetaValue(id = "a/b/c", where = where)
existsMetaValue(id = "a/b/c/d", where = where)
existsMetaValue(id = "c/d/e", where = where)

##------------------------------------------------------------------------------
## Sub ID //
##------------------------------------------------------------------------------

where <- new.env()
setMetaValue(id = "a/b/c", value = 10, where = where, sub_id = "sub")
ls(where)
existsMetaValue(id = "a/b/c", where = where, sub_id = "sub")
existsMetaValue(id = "a/b/c/d", where = where, sub_id = "sub")
existsMetaValue(id = "c/d/e", where = where, sub_id = "sub")


## End(Not run)

rappster/optionr documentation built on May 26, 2019, 11:23 p.m.