pmap_qto (#9)

Changes:
	- Introduces a pmap_qto to compliment the map_qto function introduced by @elipousson
    - map_qto should be slightly more performant (function building is done outside the map call)
    - collapse and sep are now passed to .type functions where relevant

NAMESPACE

@@ -2,6 +2,7 @@
 
 S3method(print,quarto_block)
 export(map_qto)
+export(pmap_qto)
 export(qto_attributes)
 export(qto_block)
 export(qto_callout)

R/import-standalone-purrr.R

@@ -0,0 +1,53 @@
+# nocov start
+
+#' all functions here are copied from the
+#' `standalone-purrr.R` script in rlang:
+#' https://github.com/r-lib/rlang/blob/main/R/standalone-purrr.R
+#' @noRd
+map <- function(.x, .f, ...) {
+    .f <- as_function(.f, env = global_env())
+    lapply(.x, .f, ...)
+}
+
+#' @noRd
+map_chr <- function(.x, .f, ...) {
+    .rlang_purrr_map_mold(.x, .f, character(1L), ...)
+}
+
+#' @noRd
+map_int <- function(.x, .f, ...) {
+    .rlang_purrr_map_mold(.x, .f, integer(1), ...)
+}
+
+#' @noRd
+.rlang_purrr_map_mold <- function(.x, .f, .mold, ...) {
+    .f <- as_function(.f, env = global_env())
+    out <- vapply(.x, .f, .mold, ..., USE.NAMES = FALSE)
+    names(out) <- names(.x)
+    out
+}
+
+#' @noRd
+pmap <- function(.l, .f, ...) {
+    .f <- as.function(.f)
+    args <- .rlang_purrr_args_recycle(.l)
+    do.call("mapply", c(
+        FUN = list(quote(.f)),
+        args, MoreArgs = quote(list(...)),
+        SIMPLIFY = FALSE, USE.NAMES = FALSE
+    ))
+}
+
+#' @noRd
+.rlang_purrr_args_recycle <- function(args) {
+    lengths <- map_int(args, length)
+    n <- max(lengths)
+
+    stopifnot(all(lengths == 1L | lengths == n))
+    to_recycle <- lengths == 1L
+    args[to_recycle] <- map(args[to_recycle], function(x) rep.int(x, n))
+
+    args
+}
+
+# nocov end

R/map.R

@@ -1,23 +1,28 @@
-#' map, map_chr, and .rlang_purrr_map_mold are copied from the
-#' `standalone-purrr.R` script in rlang:
-#' https://github.com/r-lib/rlang/blob/main/R/standalone-purrr.R
-#' @noRd
-map <- function(.x, .f, ...) {
-    .f <- as_function(.f, env = global_env())
-    lapply(.x, .f, ...)
+partial_qto_func <- function(f, collapse, sep) {
+    if (identical(f, qto_callout)) {
+        function(...) f(...)
+    } else if ((identical(f, qto_div))) {
+        function(...) f(..., collapse = collapse)
+    } else {
+        function(...) f(..., collapse = collapse, sep = sep)
+    }
 }
 
-#' @noRd
-map_chr <- function(.x, .f, ...) {
-    .rlang_purrr_map_mold(.x, .f, character(1L), ...)
-}
-
-#' @noRd
-.rlang_purrr_map_mold <- function(.x, .f, .mold, ...) {
-    .f <- as_function(.f, env = global_env())
-    out <- vapply(.x, .f, .mold, ..., USE.NAMES = FALSE)
-    names(out) <- names(.x)
-    out
+resolve_mapping_function <- function(f = NULL,
+                                     type = NULL,
+                                     collapse = NULL,
+                                     sep = NULL,
+                                     call = NULL) {
+    f <- f %||% switch(type,
+        block   = partial_qto_func(qto_block, collapse, sep),
+        div     = partial_qto_func(qto_div, collapse, sep),
+        callout = partial_qto_func(qto_callout, collapse, sep),
+        heading = partial_qto_func(qto_heading, collapse, sep),
+    )
+    if (!is_function(f)) {
+        f <- as_function(f, call = call)
+    }
+    f
 }
 
 #' Apply a function to each element of a vector and return Quarto block vector
@@ -35,7 +40,8 @@ map_chr <- function(.x, .f, ...) {
 #'   "heading".
 #' @param .sep,.collapse Additional parameters passed to [qto_block()] if .f
 #'   does not return a quarto block class object. Ignored if .f does return a
-#'   quarto block class object.
+#'   quarto block class object. Also passed to the relevant .type function if it supports
+#'   the collapse and/or sep parameters.
 #' @inheritParams rlang::args_error_context
 #' @examples
 #' qto_list <- map_qto(
@@ -45,37 +51,89 @@ map_chr <- function(.x, .f, ...) {
 #'
 #' qto_block(qto_list)
 #'
+#' @seealso [quartools::pmap_qto()], [purrr::map()]
 #' @export
 map_qto <- function(.x,
                     .f = NULL,
                     ...,
                     .type = c("block", "div", "callout", "heading"),
                     .sep = "",
                     .collapse = "",
-                    .call = caller_env()) {
+                    call = caller_env()) {
     .type <- arg_match(.type, error_call = call)
-
+    .f <- resolve_mapping_function(
+        f = .f,
+        type = .type,
+        collapse = .collapse,
+        sep = .sep,
+        call = call
+    )
     map(
         .x,
-        \(x) {
-            .f <- .f %||% switch(.type,
-                block = qto_block,
-                div = qto_div,
-                callout = qto_callout,
-                heading = qto_heading
-            )
-
-            if (!rlang::is_function(.f)) {
-                .f <- rlang::as_function(.f, call = call)
-            }
-
+        function(x) {
             x <- .f(x, ...)
-
-            if (inherits(x, "quarto_block")) {
-                return(x)
-            }
-
-            qto_block(x, sep = .sep, collapse = .collapse, call = .call)
+            if (inherits(x, "quarto_block")) return(x)
+            qto_block(x, sep = .sep, collapse = .collapse, call = call)
         }
     )
 }
+
+#' Map over multiple inputs simultaenously and return Quarto block vector
+#'
+#' [pmap_qto()] loops a list of vectors over a package function defined by .type or a custom
+#' function that returns a quarto block output. This function always returns a
+#' list of quarto block objects.
+#'
+#' @param .l An input vector.
+#' @inheritParams rlang::args_error_context
+#' @inheritParams map_qto
+#' @examples
+#' qto_list <- pmap_qto(
+#'     list(
+#'         list("Answer:", "Answer:", "Answer:"),
+#'         list("Yes", "No", "Yes")
+#'     )
+#' )
+#' qto_block(qto_list)
+#'
+#' qto_list <- pmap_qto(
+#'     mtcars[seq(3L), seq(3L)],
+#'     function(mpg, cyl, disp) {
+#'         qto_li(
+#'             .list = list(
+#'                 sprintf("mpg is: %s", mpg),
+#'                 sprintf("cyl is: %s", cyl),
+#'                 sprintf("disp is: %s", disp)
+#'             )
+#'         )
+#'     }
+#' )
+#' qto_block(qto_list)
+#'
+#' @seealso [quartools::map_qto()], [purrr::pmap()]
+#' @export
+pmap_qto <- function(.l,
+                     .f = NULL,
+                     ...,
+                     .type = c("block", "div", "callout", "heading"),
+                     .sep = "",
+                     .collapse = "",
+                     call = caller_env()) {
+    .type <- arg_match(.type, error_call = call)
+    .f <- resolve_mapping_function(
+        f = .f,
+        type = .type,
+        collapse = .collapse,
+        sep = .sep,
+        call = call
+    )
+    pmap(
+        .l,
+        function(...) {
+            x <- .f(...)
+            if (inherits(x, "quarto_block")) return(x)
+            qto_block(x, sep = .sep, collapse = .collapse, call = call)
+        },
+        ...
+    )
+}