Ban <<- from code base

R/export.r

@@ -119,21 +119,21 @@ parse_export_specs = function (info, exprs, mod_ns) {
         }
     }
 
-    block_error = function (export) {
-        throw(
-            'the {"@export";"} tag may only be applied to assignments or ',
-            '{"use";"} declarations;\n',
-            'used incorrectly in line {location}:\n',
-            '    {paste(code, collapse = "\n    ")}',
-            code = deparse(attr(export, 'call'), backtick = TRUE),
-            location = attr(export, 'location')[1L]
-        )
-    }
-
     exports = parse_export_tags(info, exprs, mod_ns)
     unique(flatmap_chr(parse_export, exports))
 }
 
+block_error = function (export) {
+    throw(
+        'the {"@export";"} tag may only be applied to assignments or ',
+        '{"use";"} declarations;\n',
+        'used incorrectly in line {location}:\n',
+        '    {paste(code, collapse = "\n    ")}',
+        code = deparse(attr(export, 'call'), backtick = TRUE),
+        location = attr(export, 'location')[1L]
+    )
+}
+
 #' @keywords internal
 #' @rdname parse_export_specs
 use_call = quote(box::use)
@@ -311,14 +311,16 @@ add_comments = function (refs) {
 #' tag, \code{FALSE} otherwise.
 #' @keywords internal
 has_export_tag = function (ref) {
+    self = environment()
+
     next_char = function () {
-        pos <<- pos + 1L
+        self$pos = pos + 1L
         substr(line, pos, pos)
     }
 
     consume_char = function (chars) {
         matched = next_char() %in% chars
-        if (! matched) pos <<- pos - 1L
+        if (! matched) self$pos = pos - 1L
         matched
     }
 
@@ -336,7 +338,7 @@ has_export_tag = function (ref) {
         if (! consume_char('#')) return(FALSE)
         consume_chars('#')
         if (! consume_char("'")) {
-            pos <<- prev
+            self$pos = prev
             return(FALSE)
         }
         consume_whitespace()
@@ -349,7 +351,7 @@ has_export_tag = function (ref) {
     }
 
     is_export = function () {
-        pos <<- pos + 1L
+        self$pos = pos + 1L
         len = nchar('@export')
         substr(line, pos, pos + len) == '@export' &&
             (pos + len > nchar(line) || substr(line, pos + len, pos + len) %in% c(' ', '\t'))

tests/testthat/mod/a.r

@@ -20,11 +20,12 @@ private_modname = box::name()
 # Variables at namespace scope are locked so mutable variables need to be
 # wrapped inside a closure.
 make_counter = function () {
+    self = environment()
     counter = 1L
 
     list(
         get = function () counter,
-        inc = function () counter <<- counter + 1L
+        inc = function () self$counter = counter + 1L
     )
 }
 

tests/testthat/mod/hooks/a.r

@@ -7,10 +7,11 @@ on_load_called = 0L
 
 #' @export
 register_unload_callback = local({
+    self = environment()
     unloaded = NULL
 
     function (callback) {
-        unloaded <<- callback
+        self$unloaded = callback
     }
 }, envir = (callback = new.env()))
 

tests/testthat/mod/issue76.r

@@ -13,10 +13,12 @@ h = function() {
     helper()
 }
 
+ns = environment()
+
 #' @export
 helper_var = 0L
 
-helper = function() { helper_var <<- helper_var + 1L }
+helper = function() { ns$helper_var = helper_var + 1L }
 
 f()
 g()

tests/testthat/test-S3.r

@@ -86,6 +86,6 @@ test_that('nested functions are parsed correctly', {
 
 test_that('functions with missing arguments are parsed correctly', {
     expect_error(is_S3(quote(tag$span('foo', ))), NA)
-    expect_error(is_S3(quote(base$quote(expr = ))), NA)
-    expect_error(is_S3(quote((quote)(expr = ))), NA)
+    expect_error(is_S3(quote(base$quote(expr =))), NA)
+    expect_error(is_S3(quote((quote)(expr =))), NA)
 })

tests/testthat/test-hooks.r

@@ -17,21 +17,23 @@ test_that('on_load hook is invoked only once', {
 })
 
 test_that('on_unload hook is invoked during unloading', {
+    self = environment()
     unload_called = 0L
 
     box::use(mod/hooks/a)
-    a$register_unload_callback(function () unload_called <<- unload_called + 1L)
+    a$register_unload_callback(function () self$unload_called = unload_called + 1L)
 
     expect_equal(unload_called, 0L)
     box::unload(a)
     expect_equal(unload_called, 1L)
 })
 
 test_that('hooks are invoked during reloading', {
+    self = environment()
     unload_called = 0L
 
     box::use(mod/hooks/a)
-    a$register_unload_callback(function () unload_called <<- unload_called + 1L)
+    a$register_unload_callback(function () self$unload_called = unload_called + 1L)
 
     expect_equal(unload_called, 0L)
     box::reload(a)