New features

  • the argument .message of the check_ functions is now interpolated with string_magic()

User-level changes

  • the type l0 has been removed. Now vector targets receiving something 0-length in input will not fail (in the previous version, l0 was required). Vector length can still be checked with the len(a,b) mechanism.

Minor changes

  • to increase clarity, now the problem leading to an error is displayed in a newline with the suffix PROBLEM in uppercase

  • improve clarity of error messages involving lower than/greater than

Bug fixes

  • fix display problem in fsignif

  • inrease the requirement of stringmagic version to be compatible with R v3.5.0

  • the check_arg family of functions now correctly reports the full call stack when requested

New functions

  • New set of hook error and warning functions for reporting in complex internal functions. These are set_hook to set a function as the hook and stop_hook/warn_hook error and warning functions used to report as if they were called from the hooked function.

  • warni and stopi for warning and stop functions with character interpolation using stringmagic

New type

  • The type path has been added to check_arg. It is used to check paths.

Improvements

  • All warning and stop functions gain string interpolation with stringmagic.

Bug fixes

  • fixes fit_screen so that it does not mess with white spaces.

Name changes

  • Functions check_arg_plus and check_value_plus become check_set_arg and check_set_value to improve clarity.

Improvements

  • fsignif now displays trailing 0s appropriately and is neutral to character vectors (instead of throwing an error).

  • the comparison types now can evaluate values from the calling frame:


z = 32
x = 77
try(check_value(x, "numeric scalar LE{z}"))
#> Error: in check_value(x, "numeric scalar LE{z}"):
#>  Value 'x' must be a numeric scalar lower than, or equal to, 32. Problem: it is strictly greater than 32.
  • stop_up now accepts the argument msg which is an extra message displayed right after the error message.
Bug fixes
  • in check_arg_plus conversion of factors to characters now works properly.

  • Fix bug in stop_up when the argument up was not appropriately set by the user.

  • fix bug in sfill regarding the combined usage of anchor and right in special circumstances.

New features
  • now sfill accepts 0-length vectors.

  • new exported function: fit_screen.

Bug fixes
  • fix bugs in sfill:

    • when an anchor was provided and all characters before that were of the same length.

    • when an anchor was provided and the fill was from the right.

User visible changes
  • check_family: objects are now returned invisibly.

  • new function fsignif which is an alias of signif_plus.

Bug fixes
  • Bug when using commas or parentheses in arguments .prefix or .argname of check_value.
  • Bug in the error message in check_value when the argument could not be evaluated.
  • Bug introduced in the previous version, when checking types or equality with the option “no na”
User visible changes
  • validate_dots: nicer messages.
Important changes (no retro compatibility)
  • IMPORTANT CHANGE: Now by default, there is NA tolerance for the main classes vector and matrix (opposite to the previous behavior). The new keywords NO NA replace the former keywords NA OK for these classes.
test = function(x){
  check_arg(x, "numeric vector")
}
# Before (version <= 1.1.0)
test(c(5, NA)) # => Error
# Now (version >= 1.2.0)
test(c(5, NA)) # => is OK
  • IMPORTANT CHANGE: values of 0 or 1 are not valid by default anymore when the logical type is requested.
test = function(x){
    check_arg(x, "logical scalar")
}
# Before (version <= 1.1.0)
test(0) # => is OK
# Now (version >= 1.2.0)
test(0) # => Error, must be logical

The new behavior is equivalent to the previous behavior when the type was strict logical. Now strict logical has been removed and loose logical has been introduced which accepts 0 and 1. Why this change? I remarked that when you allow arguments of very different types, one of which was a logical scalar, it was really useful to distinguish between them safely using isTRUE or is.logical. With the previous default behavior you could have a 0 or 1 that would prevent you from doing that. Of course you could use strict logical to trigger that behavior but it was non-intuitive.

New features
  • In check_value: you can use the new argument .prefix to design the error message.

  • Function check_value_plus now returns the value of the element it has checked and possibly modified.

x = "t"
y = check_value_plus(x, "match(This, Is, Raw)")
y # => "This"
fml = ~head(Petal.Length)
z = check_value_plus(fml[[2]], "evalset numeric vector", .data = iris)
z
  • sfill now accepts NAs.
Other changes
  • Error messages in check_value have been improved.

  • enumerate_items now returns the empty string when 0-length vectors are in input.

Bug correction
  • The main class match could lead the argument to lose its attributes (like names), now corrected.

  • Vectors containing only NAs when NAs are tolerated could lead to a wrong error message, now corrected.

  • Bug when check_value_plus was called from the global environment and an error was triggered.

  • Bug when check_value was called and .arg_name was provided.

  • Bug when the “...” argument contained NULL values.

  • The developer mode now never applies to functions from packages using dreamerr

  • Behavior of argument nmax in enumerate_items is fixed.

  • Type conversion of matrices returned a vector, now corrected.

New functions
  • sfill: formatting function for strings. Fills a character string up to the required length. Helps to form nice messages.

  • set_up: sets the argument up semi-globally (i.e. throughout all calls within a function).

  • set_check: turns on/off argument checking semi-globally (i.e. throughout all calls within a function).

New features
  • When devising your own message (with argument .message), you can use the special character __ARG__. If found, it will be replaced by the appropriate argument name.
User visible changes
  • Message informing no NA tolerance in the types is prompted only when the error comes from NA values.

  • The developer mode catches more errors and provide more suggestions.

  • check_value now doesn’t throw an error for missing .x.

Change in argument names
  • .call_up becomes .up – retro-compatibility is NOT ensured.
Bug correction
  • Small bug that could occur for the types "integer scalar na ok" with the argument equal to NA.

  • Important bug when using features requiring evaluations in the environment. Now the default environment is set up appropriately.

  • Bug when using var(data,env) in a formula class with missing data.

  • Very sneaky bug when badly forming a call to check_arg to check ... in nested functions is now caught.

  • In enumerate_items, when there were many elements, quote = TRUE led to quote the XX others that shouldn’t be quoted. Now corrected.

  • In the formula class, if a variable was passed as a Formula (notice the capital F), this caused an error if one-sidedness or two-sidedness were to be checked.

  • Bug when in n_letter when negative numbers are in. This bug propagated into check_arg.

This package is the outcome of over a decade of coding and developing packages in R. As a package developer I always wanted my code to be “safe”: so that if a user provides arguments of the good type the functions always work, and if there’s an argument of the wrong type then an informative error message is shown.

The big problem is that error handling is extremely time consuming, especially if you want to specify informative error messages stating clearly where the problem comes from. This problem is compounded when you want to offer the user flexible arguments that can be of many types. To do error handling properly in such situations is a nightmare: you end up with big if/else trees with a lot of different messages. And it doesn’t improve the speed of your code! So you have little incentives to invest time in proper error handling.

This is why I developed this function. It’s one line of code, and it does all the work for you. From the developer side it’s super simple, and from the user side, s/he ends up with extremely informative error messages therefore saving a lot of time in debugging.