New Features

TERR has new functions and changes to existing functions and behavior to match new functions and changes in open-source R 4.0.2.

TERR has been tested with the rtools40 utilities for building packages with C code under Windows.

TERR CMD config now supports the RANLIB and AR make variables and the C++ related variables for C++20 (similar to the ones for 11, 14, and 17).

Table 1. New functions in included packages
Package	Name	Details
base	`activeBindingFunction(sym,env)`	This function retrieves the function for the active binding, the `fun` argument to `makeActiveBinding(sym,fun,env)`.
base	`chkDots`	This function warns the user if unrecognized arguments are passed using the `...` formal argument.
base	`deparse1`	This function is like `deparse()`, except that it always returns a single (perhaps long) string. This function was added to open-source R 4.0.0.
base	`globalCallingHandlers`	This function is used for establishing session-wide condition handlers. This function was added to open-source R 4.0.0.
base	`hasName(x, name)`	This function is equivalent to `is.element(name, names(x))`. Given an object and a name, this function returns if the object has the name.
base	`infoRDS`	This function provides details about an RDS file made by `saveRDS()`.
base	`...names`	This function returns the names attached to the `...` arguments in the call to a function calling `...names()`. This function was added to open-source R a short time after the release of open-source R 4.0.0.
base	`numToBits numToInts`	These functions inspect the bits in double-precision numbers. These functions were added to open-source R after the release of open-source R 4.0.2.
base	`str2expression str2lang`	These functions provide convenient interfaces for parsing strings into expressions and language objects, respectively.
base	`suspendInterrupts(expr) allowInterrupts(expr)`	These functions execute an expression while suspending or enabling user interrupts. Finalizers are now executed with interrupts suspended.
base	`tryInvokeRestart`	This function behaves the same as `invokeRestart`, except that it silently returns `NULL` instead of generating an error if the named restart is not found. This function is called in various system functions, preventing errors in some cases. This function was added to open-source R 4.0.0.
base	`valid.factor(object)`	This function was added to open-source R 3.4.0.
base	`withAutoprint`	This function is an alternative interface to the `source()` function, with defaults set to emulate the usual parse-evaluate-print loop used in the command line interface. This function was added to open-source R 4.0.0.
methods	`el el<-`	These functions have been implemented because they are used by the networkDynamics package. They are wrappers for other operators for backwards compatibility and should not be used for new code.
stats	`DF2formula`	This function was added to open-source R 3.6.0.
tools	`package_native_routine_ registration_skeleton`	This function creates a C code file that registers the compiled routines in a package.
tools	`R_user_dir`	This function gives standard locations for user- and package-specific directories in which package writers can store folders, files, and objects. This function was added to open-source R 4.0.0.
tools	`vignetteInfo`	This function parses the `%\Vignette*` entries in the source file of a vignette.
utils	`isS3stdGeneric(f)`	This function tells if the function `f` is a call to `UseMethod()`.
utils	`packageDate`	Given a package name, this function returns the date the package was created or built.

Table 2. New R C API EntriesThe following R C API entries are implemented to improve package loading and compatibility. For a complete listing of the Rapi C API entries implemented in TERR, run the following.
`library(terrUtils) implementedRapiEntries()`
R C API entries	Description
`CAR0`	This RAPI entry is required if you use the Rcpp library built for open-source R 4.0 to load into TERR.
`Rf_lgamma`	This RAPI entry computes `log(gamma(1+x))` accurately for small `abs(x)`.
`EXTPTR_PTR`	This RAPI entry is used by the Rcpp packages in open-source R 4.0.2.
`R_ActiveBindingFunction`	This RAPI entry has the same behavior as the open-source R function `activeBindingFunction()`. This RAPI entry was added to open-source R 4.0.0.
`R_ContinueUnwind R_MakeUnwindCont R_UnwindProtect`	These RAPI entries are now fully implemented to correctly facilitate unwinding an error and continuing error processing using a continuation object.


R C API entries	Description
`GEStrMetric`	This RAPI entry is required for the systemfonts package to be loaded. `GEStrMetric` is not functional, so calls to it do not give expected results; Calls to it result in a warning.
`R_removeVarFromFrame`	This RAPI entry is used for removing a variable from an environment. This is useful because `Rf_defineVar` can no longer be used to remove a variable from an environment. This function was added to match the implementation in open-source R 4.0.0.
`R_RestoreHashCount`	This RAPI entry is needed to load the qs package.
`R_tryCatch R_tryCatchError`	These RAPI entries were added to open-source R 3.4.0.
`R_withCallingErrorHandler`	This RAPI entry was added to open-source R 4.0.0.
`Rf_FixupDigits Rf_FixupWidth`	These RAPI entries were added to open-source R 4.0.0.
`Rf_installNoTrChar`	(See `Rf_installTrChar`.)
`Rf_installTrChar`	This RAPI entry has the same behavior as `Rf_installChar`. It supports building and loading CRAN packages such as lfe that call `installChar`, which expands to `Rf_installTrChar`, beginning with R 4.0.0.
`Rf_log1mexp`	This RAPI entry computes `log(1-exp(-x)`) for non-negative `x` with minimal loss of precision.
`Rf_onintr`	This RAPI entry is fully implemented so it no longer produces a `"not implemented"` warning. Now, the RAPI entry interrupts the current evaluation. Interrupts created by a call to `Rf_onintr`, or by pressing an interrupt key combination, are now processed through the condition system, so they can be caught by `tryCatch(...,interrupt=...)`.
`SET_GROWABLE_BIT IS_GROWABLE`	These RAPI entries are required to load the readr package v1.4.0.
`SETLEVELS`	This RAPI entry is needed to load the qs package.
`R_EvalSymbol`	This R C API symbol is now exported so that packages using it can be loaded into TERR.
`Rf_PairToVectorList(SEXP pairlist)`	This R C API entry converts a `pairlist` to a list.
`R_Serialize R_Unserialize R_InitOutPStream R_InitInPStream`	These R C API entries are called by the qs and RApiSerialize packages.