Handle blank indices in simplifyForLoops

Author: kenkellner

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: nimbleMacros
-Version: 0.1.1.9002
-Date: 2026-04-30
+Version: 0.1.1.9003
+Date: 2026-06-09
 Title: Macros Generating 'nimble' Code
 Authors@R: c(person("Ken", "Kellner", email="contact@kenkellner.com", 
                     role=c("cre","aut")),

R/utilities.R

@@ -195,6 +195,8 @@ simplifyIndices <- function(code, new_indices){
     if(is.name(x) | is.symbol(x)) return(x)
     if(x[[1]] == "for"){    
       unique_idx <- unique(extractAllIndices(x))
+      # Ignore blank indices as in x[i,]
+      unique_idx <- unique_idx[sapply(unique_idx, function(x) x!="")]
       if(length(unique_idx) > length(new_indices)){
         stop("Not enough new indices provided", call.=FALSE)
       }

tests/testthat/test_simplifyForLoops.R

@@ -123,3 +123,32 @@ test_that("More complex case of an occupancy model", {
   expect_error(simplifyForLoops(mod$getCode(), new_indices=list(quote(i))),
                "Not enough new indices provided")
 })
+
+test_that("Blank index slot is ignored", {
+  # e.g. in x[1:n,] we should not add a new index letter for the ,]
+  # presumably this would occur when you are planning to add the dimensions
+  # to the dimensions argument manually
+
+  test <- nimbleCode({
+    for (i in 1:3){
+      x[i] <- y[i] + 1
+    }
+
+    for (j in 1:3){
+      z[j,] <- 0
+    }
+
+  })
+
+  out <- simplifyForLoops(test)
+
+  expect_equal(out,
+    quote({
+      for (i in 1:3){
+        x[i] <- y[i] + 1
+        z[i,] <- 0
+      }
+    })
+  )
+})
+