% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/docs_types.R
\name{type_objects}
\alias{type_objects}
\title{Types in R and TypeScript}
\description{
This document provides an overview of the main types available to
app developers, which includes the main types in R and their
TypeScript counterparts.
}
\section{TS objects}{
The basic object in \code{ts} is a \code{ts_object} class. This is represented by
input and return types, an optional default value, and a checking
function.

Input types describe the \code{zod} schema of objects that TypeScript can pass
to Rserve functions.

Return types describe the \code{zod} schema of objects that Rserve functions,
and most of these utilise the \code{Robj} utility types in the \code{rserve-ts}
library. The return types have additional properties added,
namedly \code{r_type} and \code{r_attributes}, handled by the \code{Robj} utility types.

\strong{Scalar versus array ("vector") types}:
In R, almost all types are vectors. In the 'rserve-js' library,
primitive arrays of length one are converted into scalars, which
leads to some issues with type checking when, for example, a return value
has unknown length. \code{which(x > 5)} is one such example.

To solve this, we add an \code{n} argument to the \verb{ts_*} functions. When \code{n = 1},
the type takes the \emph{scalar} form of the alue. When \code{n != 1}, the type takes
the \emph{array} form of the value (this includes 0). Otherwise, the type
is the union of the scalar and array forms.

This is the case for numbers, strings, and booleans.
}

\section{Available types}{
\itemize{
\item \code{ts_boolean}: A boolean value. The array type is \code{Int8Array}.
\item \code{ts_integer}: An integer value. The array type is \code{Int32Array}.
Javascript does not have a native integer type,
so scalars are represented as a number
(the same as \code{ts_numeric}).
\item \code{ts_numeric}: A numeric value. The array type is \code{Float64Array}.*
\item \code{ts_string}: A string value. The array type is \code{string[]}.
\item \code{ts_factor}: A factor value. The array type is \code{(level1 | level2 | ... | levelN)[]}, and this type does not have a scalar form.
\item \code{ts_list}: A list value, represented by a named object or an array.
\item \code{ts_dataframe}: A data frame value, represented by a named object.
\item \code{ts_null}: A null value.
\item \code{ts_void}: A void value, used for specifying return types of functions
that do not return a value.
}
}

\concept{type documentation}