Define a typed function

Usage

ts_function(f, ..., result = ts_void(), export = FALSE)

Arguments

f: an R function
...: argument definitions (only required if f does not specify these in its formals)
result: return type (ignored if overloads are provided)
export: if TRUE, and defined in the global namespace of the app at compile time, the function will be part of the initial functions available to 'Rserve'; otherwise it will need to be sent as the result of another Ocap.

Value

a ts_function() object which has a call() method that will call the function with the given arguments, which will be checked for type correctness.

Details

Defining functions is the core of writing 'Rserve' apps. Functions are referred to as object capabilities (Ocaps), as they are 'objects' that allow 'JavaScript' to access capabilities of R with a restricted interface. Only arguments can be adjusted.

ts_function() objects can be defined using existing (named) or anonymous functions. Anonymous functions are useful in that the arguments to the functions can explicitly be defined with their types as formal arguments:

ts_function(function(x = ts_integer(), y = ts_string()) { ... })

Examples

f <- ts_function(function(x = ts_integer(1), y = ts_character(1)) {
    x + nchar(y)
}, result = ts_integer(1))
f$call(1, "hello")
#> [1] 6