rJava: jsimplify – R documentation

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jsimplify

Converts Java object to a simple scalar if possible

Description

.jsimplify attempts to convert Java objects that represent simple scalars into corresponding scalar representation in R.

Usage

.jsimplify(o, promote=FALSE)

Arguments

`o`	arbitrary object
`promote`	logical, if `TRUE` then an ambiguous conversion where the native type value would map to `NA` (e.g., Java `int` type with value -2147483648) will be taken to represent an actual value and will be promoted to a larger type that can represent the value (in case of `int` promoted to `double`). If `FALSE` then such values are assumed to represent `NA`s.

Details

If o is not a Java object reference, o is returned as-is. If o is a reference to a scalar object (such as single integer, number, string or boolean) then the value of that object is returned as R vector of the corresponding type and length one.

This function is used by .jfield to simplify the results of field access if required.

Currently there is no function inverse to this, the usual way to wrap scalar values in Java references is to use .jnew as the corresponding constructor.

Value

Simple scalar or o unchanged.

Examples

## Not run: 
i <- .jnew("java/lang/Integer", as.integer(10))
print(i)
print(.jsimplify(i))

## End(Not run)

rJava

Low-Level R to Java Interface

v1.0-4

LGPL-2.1

Authors

Simon Urbanek <simon.urbanek@r-project.org>

Initial release