improve the way AGENTS.md is generated

vignettes/_AGENTS.Rmd

@@ -76,15 +76,23 @@ In addition to help the analysis these two packages might be used on modules:
 - Group related utilities in shared files (e.g., `utils.R`, `validations.R`).
 
 ```{r teal_content, echo=FALSE, results='asis'}
-# Append common shared instructions from teal framework (special case as they are on this repo)
-common_agents_shared <- readLines(params$url)
-# remove a heading line only intented to aovid a markdown lint error
-line_to_avoid_lintr <- grep("^# ", common_agents_shared)
-# remove section intended only for module packages
-begins_module_section <- grep("<!-- Begins Module Section", common_agents_shared, fixed = TRUE)
-ends_module_section <- grep("<!-- Ends Module Section", common_agents_shared, fixed = TRUE)
-common_agents_shared <- common_agents_shared[
-  -1 * c(line_to_avoid_lintr, seq(from = begins_module_section, to = ends_module_section))
-]
-cat(common_agents_shared, sep = "\n")
+# Append common shared instructions from teal framework
+common_agents_url <- params$url
+common_agents_shared <- readLines(common_agents_url)
+# remove optional sections
+remove_sections <- c("<!-- (Begins|Ends) Module Section")
+Reduce(
+  function(x, y) {
+    delim <- grep(y, x)
+    if (length(delim) == 0) {
+      return(x)
+    } else if (length(delim) != 2) {
+      stop("Section delimiters are not balanced")
+    }
+    x[-1 * seq(from = delim[1], to = delim[2])]
+  },
+  remove_sections,
+  init = common_agents_shared
+) |>
+  cat(sep = "\n")
 ```