Merge pull request #399 from lucdw/master

Global switch (and function) to use lavaanC.

NAMESPACE

@@ -61,7 +61,7 @@ export("lavaan", "cfa", "sem", "growth",
        "lavResiduals",
        # utilities
        "getCov", "char2num", "cor2cov",
-       "lavOptions",
+       "lavOptions", "lav_use_lavaanC",
 
        "modindices", "modificationIndices", "modificationindices",
        "standardizedSolution", "standardizedsolution",

R/lav_options_default.R

@@ -2,6 +2,28 @@
 
 lavaan_cache_env <- new.env(parent = emptyenv())
 
+# function to get or set the switch to use c++ code in lavaanC
+lav_use_lavaanC <- uselavaanC <- function(x) {
+  if (missing(x)) {
+    if (!exists("opt.lavaanC", lavaan_cache_env)) {
+      assign("opt.lavaanC", requireNamespace("lavaanC", quietly = TRUE), lavaan_cache_env)
+    }
+    return(get("opt.lavaanC", lavaan_cache_env))
+  } else {
+    if (!is.logical(x) || length(x) != 1L) 
+      lav_msg_stop(gettext("'x' must be a scalar logical"))
+    if (x) {
+      if (!requireNamespace("lavaanC", quietly = TRUE)) {
+        lav_msg_warn(gettext("cannot use lavaanC, package not found."))
+        assign("opt.lavaanC", FALSE, lavaan_cache_env)
+        return(invisible(NULL))
+      }
+    }
+    assign("opt.lavaanC", x, lavaan_cache_env)
+    return(invisible(NULL))
+  }
+}
+
 # functions to handle warn/debug/verbose options
 #             (no longer in 'standard' options)
 # if x not present returns the current value of opt.warn/debug/verbose

R/lav_syntax_parser_cr.R

@@ -9,7 +9,7 @@ ldw_parse_model_string_cr <- function(model.syntax = "",
     paste(unlist(model.syntax), "", collapse = "\n")
   )
 
-  if (requireNamespace("lavaanC", quietly = TRUE)) {
+  if (lav_use_lavaanC()) {
     flat <- lavaanC::lav_parse_model_string_c(modelsrc)
   } else {
     flat <- lav_parse_model_string_r(modelsrc)

man/lav_use_lavaanC.Rd

@@ -0,0 +1,27 @@
+\name{lav_use_lavaanC}
+\alias{lav_use_lavaanC}
+\alias{uselavaanC}
+\title{use C++ code in lavaanC}
+\description{
+Get or set switch to use the C++ code in lavaanC.}
+\usage{
+lav_use_lavaanC(x)
+}
+\arguments{
+\item{x}{Optional scalar logical to set the switch ON or OFF.}
+}
+\value{
+If \code{x} is missing the current value of the switch (logical). 
+If \code{x} is provided invisible(NULL).
+}
+\details{
+The default value of the switch is ON (TRUE) if the \code{lavaanC} is available and
+OFF (FALSE) if it is not. The switch cannot be set to TRUE if \code{lavaanC} is not available
+(a warning message is issued).
+}
+\examples{
+lav_use_lavaanC(FALSE)
+lav_use_lavaanC()
+lav_use_lavaanC(TRUE)
+lav_use_lavaanC()
+}