ts/README.md

ts

The ts package makes it easy for users to write functions that can be used in rserve-ts applications.

Installation

You can install the development version of ts from GitHub with:

# install.packages("devtools")
devtools::install_github("tmelliott/ts")

Example

Writing functions is easy, just use the ts::x() functions to define formals and return types.

Note: we recommend not importing the library, and instead using the fully qualified name ts::x() to avoid conflicts with other libraries.

app <- ts::app(
  add = ts::fun(
    function(x = ts::number(), y = ts::number()) {
      result <- x + y
      ts::result(result, ts::number())
    }
  ),
  sample = ts::fun(
    function(x = ts::character_vector(), n = ts::integer()) {
      result <- sample(x, n)
      ts::result(result,
        ts::condition(n,
          1 = ts::character(),
          ts::character_vector()
        )
      )
    }
  )
)

ts::compile(app)

This will generate the following rserve-ts function definitions:

import { types as R } from "rserve-ts";

export const app = {
  add: z.function(
    z.tuple([z.number(), z.number()]),
    z.promise(R.numeric(1))
  ),
  sample: z.function(
    z.tuple([z.character_vector(), z.integer()]),
    z.promise(R.character())
  )
};

which will generate the following types:

type App = {
  add: (x: number, y: number) => Promise<{ data: number }>;
  sample: (x: string[], n: number) => Promise<{ data: string | string[] }>;
  // or, if possible, even better:
  sample: <N extends number>(x: string[], n: N) =>
    Promise<{ data: N extends 1 ? string : string[] }>;
};