[R] address some lintr warnings (#8609)

R-package/R/callbacks.R

@@ -611,7 +611,7 @@ cb.cv.predict <- function(save_models = FALSE) {
 #' matplot(xgb.gblinear.history(bst, class_index = 0)[[1]], type = 'l')
 #'
 #' @export
-cb.gblinear.history <- function(sparse=FALSE) {
+cb.gblinear.history <- function(sparse = FALSE) {
   coefs <- NULL
 
   init <- function(env) {

R-package/R/xgb.Booster.R

@@ -629,7 +629,7 @@ xgb.attributes <- function(object) {
 #' @export
 xgb.config <- function(object) {
   handle <- xgb.get.handle(object)
-  .Call(XGBoosterSaveJsonConfig_R, handle);
+  .Call(XGBoosterSaveJsonConfig_R, handle)
 }
 
 #' @rdname xgb.config

R-package/R/xgb.cv.R

@@ -119,10 +119,10 @@
 #' print(cv, verbose=TRUE)
 #'
 #' @export
-xgb.cv <- function(params=list(), data, nrounds, nfold, label = NULL, missing = NA,
-                   prediction = FALSE, showsd = TRUE, metrics=list(),
+xgb.cv <- function(params = list(), data, nrounds, nfold, label = NULL, missing = NA,
+                   prediction = FALSE, showsd = TRUE, metrics = list(),
                    obj = NULL, feval = NULL, stratified = TRUE, folds = NULL, train_folds = NULL,
-                   verbose = TRUE, print_every_n=1L,
+                   verbose = TRUE, print_every_n = 1L,
                    early_stopping_rounds = NULL, maximize = NULL, callbacks = list(), ...) {
 
   check.deprecation(...)

R-package/R/xgb.dump.R

@@ -38,7 +38,7 @@
 #' cat(xgb.dump(bst, with_stats = TRUE, dump_format='json'))
 #'
 #' @export
-xgb.dump <- function(model, fname = NULL, fmap = "", with_stats=FALSE,
+xgb.dump <- function(model, fname = NULL, fmap = "", with_stats = FALSE,
                      dump_format = c("text", "json"), ...) {
   check.deprecation(...)
   dump_format <- match.arg(dump_format)