ts/R/function.R
2025-01-09 12:58:49 +13:00

72 lines
1.8 KiB
R

parse_args <- function(x, mc) {
fmls <- lapply(x, eval)
mc <- mc[-1]
if (!all(names(mc) %in% names(fmls))) {
stop(
"Invalid argument(s): ",
paste(setdiff(names(mc), names(fmls)), collapse = ", ")
)
}
args <- lapply(names(fmls), function(n) {
tryCatch(
{
fmls[[n]]$check(eval(mc[[n]]))
},
error = function(e) {
stop("Invalid argument '", n, "': ", e$message, call. = FALSE)
}
)
})
names(args) <- names(fmls)
args
}
check_args <- function(args, fmls) {
args <- as.list(args)[-1]
fmls <- lapply(fmls, eval)
lapply(names(fmls), function(n) {
tryCatch(
{
fmls[[n]]$check(args[[n]])
},
error = function(e) {
stop("Invalid argument '", n, "': ", e$message, call. = FALSE)
}
)
})
}
ts_result <- function(type, value) {
if (type$check(value)) {
return(value)
}
stop("Expected a value of type ", type$type)
}
#' TS function definition
#'
#' @param f an R function
#' @param ... argument definitions (only required if f does not specify these in its formals)
#' @param result return type (ignored if overloads are provided)
#' @export
ts_function <- function(f, ..., result = NULL) {
args <- list(...)
if (!is.null(result) && !is_object(result)) {
stop("Invalid return type")
}
if (length(args) == 0) {
args <- lapply(formals(f), eval)
}
fn <- function(...) {
mc <- match.call(f)
x <- parse_args(args, mc)
result$check(do.call(f, x))
}
attr(fn, "args") <- args
attr(fn, "result") <- result
class(fn) <- c("ts_function", class(f))
fn
}