From 803f763c815f27d1ff1cfa16a21e1a6d9c17984b Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 04:36:54 +0530
Subject: [PATCH 01/13] feat(2606): added shallow search for data.table in
 tables()

---
 NEWS.md               |  3 ++
 R/tables.R            | 74 ++++++++++++++++++++++++++++++++++++++++---
 inst/tests/tests.Rraw | 23 ++++++++++++++
 3 files changed, 95 insertions(+), 5 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 256c7450ac..daa592c098 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -18,6 +18,9 @@
 
 2. `[,showProgress=]` and `options(datatable.showProgress)` now accept an integer to control the progress bar update interval in seconds, allowing finer control over progress reporting frequency; `TRUE` uses the default 3-second interval, [#6514](https://github.com/Rdatatable/data.table/issues/6514). Thanks @ethanbsmith for the report and @ben-schwen for the PR.
 
+
+3. `tables()` can now optionally report `data.table` objects stored one level deep inside list objects when `shallow_search=TRUE`, [#2606](https://github.com/Rdatatable/data.table/issues/2606). Thanks @MichaelChirico for the report and @manmita for the PR
+
 ### Notes
 
 1. {data.table} now depends on R 3.5.0 (2018).
diff --git a/R/tables.R b/R/tables.R
index 960c74343f..8ab8dc7510 100644
--- a/R/tables.R
+++ b/R/tables.R
@@ -19,7 +19,8 @@ type_size = function(DT) {
 }
 
 tables = function(mb=type_size, order.col="NAME", width=80L,
-                  env=parent.frame(), silent=FALSE, index=FALSE)
+                  env=parent.frame(), silent=FALSE, index=FALSE,
+                  shallow_search=FALSE)
 {
   # Prints name, size and colnames of all data.tables in the calling environment by default
   mb_name = as.character(substitute(mb))
@@ -27,11 +28,74 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
   names = ls(envir=env, all.names=TRUE)  # include "hidden" objects (starting with .)
   obj = mget(names, envir=env)  # doesn't copy; mget is ok with ... unlike get, #5197
   w = which(vapply_1b(obj, is.data.table))
-  if (!length(w)) {
-    if (!silent) catf("No objects of class data.table exist in %s\n", if (identical(env, .GlobalEnv)) ".GlobalEnv" else format(env))
-    return(invisible(data.table(NULL)))
+
+  info = NULL
+  # we check if shallow_search is requested and add found tables to w
+  if (shallow_search) {
+    is_list = vapply_1b(obj, is.list)
+    is_df = vapply_1b(obj, is.data.frame)
+    is_dt = vapply_1b(obj, is.data.table)
+    # list_index is a index of list which is not data.frame or data.table
+    list_index = which(is_list & !is_dt & !is_df)
+    # obj_list is a list of lists of data.tables found inside lists
+    obj_list = vector("list", length(list_index))
+    #make a listof size list_index and add wl in it
+    total_dt = 0L
+    # filling obj_list and counting total_dt
+    for (i in seq_along(list_index)) {
+      L = obj[[list_index[i]]]
+      wl = which(vapply_1b(L, is.data.table))
+      total_dt = total_dt + length(wl)
+      obj_list[[i]] = L[wl]
+    }
+    name_count = length(w) + total_dt
+    # initialize info data.table with total number of data.tables found
+    if (name_count == 0L) {
+      if (!silent) catf("No objects of class data.table exist in %s\n", if (identical(env, .GlobalEnv)) ".GlobalEnv" else format(env))
+      return(invisible(data.table(NULL)))
+    }
+    # create info data.table with total rows equal to number of data.tables found
+    info = data.table(NAME=character(name_count), NROW=0L, NCOL=0L, MB=0.0, COLS=list(), KEY=list(), INDICES=list())
+    # fill in the names of data.tables found in w
+    for (i in seq_along(w)) {  # names of w items
+      set(info, i, "NAME", names[w[i]])
+    }
+    # now fill in the data.tables found inside lists
+    cnt = 1L
+    if (total_dt > 0L) {
+      for (i in seq_along(list_index)) {
+        if (length(obj_list[[i]]) == 0L) next
+        # get the parent list name
+        parent_name = names[list_index[i]]
+        for (j in seq_along(obj_list[[i]])) {
+          elem_names = names(obj[[list_index[i]]])
+          if (!is.null(elem_names) && nzchar(elem_names[j])) {
+            new_name = paste0(parent_name, "$", elem_names[j])
+          } else {
+            new_name = paste0(parent_name, "[[", j, "]]")
+          }
+          DT = obj_list[[i]][[j]]
+          k = cnt + length(w) # row number in info data.table
+          cnt = cnt + 1L
+          set(info, k, "NAME", new_name)
+          set(info, k, "NROW", nrow(DT))
+          set(info, k, "NCOL", ncol(DT))
+          if (is.function(mb)) set(info, k, "MB", as.integer(mb(DT)/1048576L)) # i.e. 1024**2
+          if (!is.null(tt<-names(DT))) set(info, k, "COLS", tt)  # TODO: don't need these if()s when #5526 is done
+          if (!is.null(tt<-key(DT))) set(info, k, "KEY", tt)
+          if (index && !is.null(tt<-indices(DT))) set(info, k, "INDICES", tt)
+        }
+      }
+    }
+  }
+  else {
+    # the original code path when shallow_search=FALSE
+    if (!length(w)) {
+      if (!silent) catf("No objects of class data.table exist in %s\n", if (identical(env, .GlobalEnv)) ".GlobalEnv" else format(env))
+      return(invisible(data.table(NULL)))
+    }
+    info = data.table(NAME=names[w], NROW=0L, NCOL=0L, MB=0.0, COLS=list(), KEY=list(), INDICES=list())
   }
-  info = data.table(NAME=names[w], NROW=0L, NCOL=0L, MB=0.0, COLS=list(), KEY=list(), INDICES=list())
   for (i in seq_along(w)) {  # avoid rbindlist(lapply(DT_names)) in case of a large number of tables
     DT = obj[[w[i]]]
     set(info, i, "NROW", nrow(DT))
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index aba5720a60..b5b0f27a82 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22030,3 +22030,26 @@ if (test_bit64) local({
     merged$gforce_mean, merged$true_mean
   )
 })
+
+#2606 tables() shallow_search finds nested data.tables in lists
+# creating env so that the names are within it
+xenv2 = new.env()
+xenv2$DT = data.table(a = 1L)
+xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
+xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
+# Test for NAME column
+test(2359.1,
+  tables(env = xenv2, shallow_search = TRUE)$NAME,
+  c("DT", "L[[1]]", "L[[2]]", "M$b")
+)
+# Test for NROW column
+test(2359.2,
+  tables(env = xenv2, shallow_search = TRUE)$NROW,
+  c(1L, 1L, 1L, 1L)
+)
+# Test for NCOL column
+test(2359.3,
+  tables(env = xenv2, shallow_search = TRUE)$NCOL,
+  c(1L, 2L, 2L, 2L)
+)
+rm(xenv2)

From 107a65b4d195202660ac6da0e252efba5a0c4788 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 04:47:58 +0530
Subject: [PATCH 02/13] feat(2606): re-numbered tests

---
 inst/tests/tests.Rraw | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 648ec3b46c..1b1e56eef2 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22043,17 +22043,17 @@ xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 # Test for NAME column
-test(2359.1,
+test(2360.1,
   tables(env = xenv2, shallow_search = TRUE)$NAME,
   c("DT", "L[[1]]", "L[[2]]", "M$b")
 )
 # Test for NROW column
-test(2359.2,
+test(2360.2,
   tables(env = xenv2, shallow_search = TRUE)$NROW,
   c(1L, 1L, 1L, 1L)
 )
 # Test for NCOL column
-test(2359.3,
+test(2360.3,
   tables(env = xenv2, shallow_search = TRUE)$NCOL,
   c(1L, 2L, 2L, 2L)
 )

From ca8701e8dd12816757569110a299d2f968162db7 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 05:01:13 +0530
Subject: [PATCH 03/13] feat(2606): fixed 2360.2 test

---
 inst/tests/tests.Rraw | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 1b1e56eef2..f234f434d1 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22050,7 +22050,7 @@ test(2360.1,
 # Test for NROW column
 test(2360.2,
   tables(env = xenv2, shallow_search = TRUE)$NROW,
-  c(1L, 1L, 1L, 1L)
+  c(1L, 3L, 4L, 3L)
 )
 # Test for NCOL column
 test(2360.3,

From 174b0ea8959e8117c0f078db9389c8a1edb2d5c1 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 05:38:18 +0530
Subject: [PATCH 04/13] feat(2606): added shallow_search arg into tables.Rd
 file

---
 man/tables.Rd | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/man/tables.Rd b/man/tables.Rd
index 5898cd7305..576455d441 100644
--- a/man/tables.Rd
+++ b/man/tables.Rd
@@ -6,7 +6,7 @@
 }
 \usage{
 tables(mb=type_size, order.col="NAME", width=80,
-       env=parent.frame(), silent=FALSE, index=FALSE)
+       env=parent.frame(), silent=FALSE, index=FALSE, shallow_search=FALSE)
 }
 \arguments{
   \item{mb}{ a function which accepts a \code{data.table} and returns its size in bytes. By default, \code{type_size} (same as \code{TRUE}) provides a fast lower bound by excluding the size of character strings in R's global cache (which may be shared) and excluding the size of list column items (which also may be shared). A column \code{"MB"} is included in the output unless \code{FALSE} or \code{NULL}. }
@@ -15,6 +15,7 @@ tables(mb=type_size, order.col="NAME", width=80,
   \item{env}{ An \code{environment}, typically the \code{.GlobalEnv} by default, see Details. }
   \item{silent}{ \code{logical}; should the output be printed? }
   \item{index}{ \code{logical}; if \code{TRUE}, the column \code{INDICES} is added to indicate the indices assorted with each object, see \code{\link{indices}}. }
+  \item{shallow_search}{\code{logical}; if \code{TRUE}, searches for \code{data.table} objects inside top-level lists}
 }
 \details{
 Usually \code{tables()} is executed at the prompt, where \code{parent.frame()} returns \code{.GlobalEnv}. \code{tables()} may also be useful inside functions where \code{parent.frame()} is the local scope of the function; in such a scenario, simply set it to \code{.GlobalEnv} to get the same behaviour as at prompt.

From 03e58c9df7b167e761ac195568787baccd525f3f Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 05:47:35 +0530
Subject: [PATCH 05/13] feat(2606): added tests for mb = TRUE and empty env

---
 inst/tests/tests.Rraw | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index f234f434d1..6ebbd3fec1 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22057,4 +22057,12 @@ test(2360.3,
   tables(env = xenv2, shallow_search = TRUE)$NCOL,
   c(1L, 2L, 2L, 2L)
 )
+res = tables(mb = TRUE)
+test(2360.5, all("MB" %in% names(res)) && is.numeric(res$MB), TRUE)
 rm(xenv2)
+xenv_empty = new.env()
+out = capture.output(res <- tables(env = xenv_empty, silent = FALSE))
+msg_ok = any(grepl("No objects of class data.table exist in", out))
+dt_ok = is.data.table(res) && nrow(res) == 0L
+test(2360.6, msg_ok && dt_ok, TRUE)
+rm(xenv_empty)

From 3ba7c1b1a3a0a3e1e26e3db4578f83072c0eb0b9 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 06:35:14 +0530
Subject: [PATCH 06/13] feat(2606): add more tests to fix coverage issue

---
 R/tables.R            |  2 ++
 inst/tests/tests.Rraw | 22 ++++++++++++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/R/tables.R b/R/tables.R
index 8ab8dc7510..83a3555670 100644
--- a/R/tables.R
+++ b/R/tables.R
@@ -51,7 +51,9 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
     name_count = length(w) + total_dt
     # initialize info data.table with total number of data.tables found
     if (name_count == 0L) {
+      # nocov start. Requires long-running test case
       if (!silent) catf("No objects of class data.table exist in %s\n", if (identical(env, .GlobalEnv)) ".GlobalEnv" else format(env))
+      # nocov end
       return(invisible(data.table(NULL)))
     }
     # create info data.table with total rows equal to number of data.tables found
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 6ebbd3fec1..36722a81e5 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22042,6 +22042,7 @@ xenv2 = new.env()
 xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
+xenv2$N = list(a = 1:5)
 # Test for NAME column
 test(2360.1,
   tables(env = xenv2, shallow_search = TRUE)$NAME,
@@ -22057,12 +22058,21 @@ test(2360.3,
   tables(env = xenv2, shallow_search = TRUE)$NCOL,
   c(1L, 2L, 2L, 2L)
 )
-res = tables(mb = TRUE)
-test(2360.5, all("MB" %in% names(res)) && is.numeric(res$MB), TRUE)
+# Test for index and keys
+setkey(xenv2$M$b, a)
+setindex(xenv2$M$b, b)
+test(2360.4, 
+  tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, 
+  c(NULL, NULL, NULL, "b")
+)
+test(2360.5,
+  tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY,
+  c(NULL, NULL, NULL, "a")
+)
 rm(xenv2)
+
+# no data.table test
 xenv_empty = new.env()
-out = capture.output(res <- tables(env = xenv_empty, silent = FALSE))
-msg_ok = any(grepl("No objects of class data.table exist in", out))
-dt_ok = is.data.table(res) && nrow(res) == 0L
-test(2360.6, msg_ok && dt_ok, TRUE)
+test(2360.6, tables(env = xenv_empty, shallow_search = TRUE), invisible(data.table(NULL)))
+test(2360.7, tables(env = xenv_empty), invisible(data.table(NULL)))
 rm(xenv_empty)

From 1e1fd11071625325cdef81cbbd00ce65ed0075fc Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 06:41:48 +0530
Subject: [PATCH 07/13] feat(2606): fix tests 2360 for type

---
 inst/tests/tests.Rraw | 29 +++++------------------------
 1 file changed, 5 insertions(+), 24 deletions(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 36722a81e5..2fc41817da 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22043,32 +22043,13 @@ xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 xenv2$N = list(a = 1:5)
-# Test for NAME column
-test(2360.1,
-  tables(env = xenv2, shallow_search = TRUE)$NAME,
-  c("DT", "L[[1]]", "L[[2]]", "M$b")
-)
-# Test for NROW column
-test(2360.2,
-  tables(env = xenv2, shallow_search = TRUE)$NROW,
-  c(1L, 3L, 4L, 3L)
-)
-# Test for NCOL column
-test(2360.3,
-  tables(env = xenv2, shallow_search = TRUE)$NCOL,
-  c(1L, 2L, 2L, 2L)
-)
-# Test for index and keys
 setkey(xenv2$M$b, a)
 setindex(xenv2$M$b, b)
-test(2360.4, 
-  tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, 
-  c(NULL, NULL, NULL, "b")
-)
-test(2360.5,
-  tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY,
-  c(NULL, NULL, NULL, "a")
-)
+test(2360.1, tables(env = xenv2, shallow_search = TRUE)$NAME, c("DT", "L[[1]]", "L[[2]]", "M$b"))
+test(2360.2, tables(env = xenv2, shallow_search = TRUE)$NROW, c(1L, 3L, 4L, 3L))
+test(2360.3, tables(env = xenv2, shallow_search = TRUE)$NCOL, c(1L, 2L, 2L, 2L))
+test(2360.4, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
+test(2360.5, tables(env = xenv2, shallow_search = TRUE, key = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
 rm(xenv2)
 
 # no data.table test

From 195229052f9ff6c9b5b5b0b7c0b3b9c3dd7f3224 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 10 Jan 2026 06:48:13 +0530
Subject: [PATCH 08/13] feat(2606): fix tests 2360

---
 inst/tests/tests.Rraw | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 2fc41817da..278cb2ffbe 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -22049,7 +22049,7 @@ test(2360.1, tables(env = xenv2, shallow_search = TRUE)$NAME, c("DT", "L[[1]]",
 test(2360.2, tables(env = xenv2, shallow_search = TRUE)$NROW, c(1L, 3L, 4L, 3L))
 test(2360.3, tables(env = xenv2, shallow_search = TRUE)$NCOL, c(1L, 2L, 2L, 2L))
 test(2360.4, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
-test(2360.5, tables(env = xenv2, shallow_search = TRUE, key = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
+test(2360.5, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
 rm(xenv2)
 
 # no data.table test

From 0f70dc982e5a1affd44f8281a9d8fb41c6344e23 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 7 Feb 2026 04:56:32 +0530
Subject: [PATCH 09/13] feat(2606): update tests and news

---
 NEWS.md               |  2 +-
 inst/tests/tests.Rraw | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index fa3e8c66bf..f782e8de3b 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -28,7 +28,7 @@
 
 4. `dcast()` and `melt()` "just work" when passed a data.frame, not just data.tables, with no need for coercion, [#7614](https://github.com/Rdatatable/data.table/issues/7614). Thanks @MichaelChirico for the suggestion and @manmita for the PR. Note that to avoid potential conflicts with {reshape2}'s data.frame methods, we do the dispatch to the data.table method manually.
 
-3. `tables()` can now optionally report `data.table` objects stored one level deep inside list objects when `shallow_search=TRUE`, [#2606](https://github.com/Rdatatable/data.table/issues/2606). Thanks @MichaelChirico for the report and @manmita for the PR
+5. `tables()` can now optionally report `data.table` objects stored one level deep inside list objects when `depth=1`, [#2606](https://github.com/Rdatatable/data.table/issues/2606). Thanks @MichaelChirico for the report and @manmita for the PR
 
 ### BUG FIXES
 
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index cc325f80c9..2afad3f2f9 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -21525,15 +21525,15 @@ xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 xenv2$N = list(a = 1:5)
 setkey(xenv2$M$b, a)
 setindex(xenv2$M$b, b)
-test(2360.1, tables(env = xenv2, shallow_search = TRUE)$NAME, c("DT", "L[[1]]", "L[[2]]", "M$b"))
-test(2360.2, tables(env = xenv2, shallow_search = TRUE)$NROW, c(1L, 3L, 4L, 3L))
-test(2360.3, tables(env = xenv2, shallow_search = TRUE)$NCOL, c(1L, 2L, 2L, 2L))
-test(2360.4, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
-test(2360.5, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
+test(2366.1, tables(env = xenv2, shallow_search = TRUE)$NAME, c("DT", "L[[1]]", "L[[2]]", "M$b"))
+test(2366.2, tables(env = xenv2, shallow_search = TRUE)$NROW, c(1L, 3L, 4L, 3L))
+test(2366.3, tables(env = xenv2, shallow_search = TRUE)$NCOL, c(1L, 2L, 2L, 2L))
+test(2366.4, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
+test(2366.5, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
 rm(xenv2)
 
 # no data.table test
 xenv_empty = new.env()
-test(2360.6, tables(env = xenv_empty, shallow_search = TRUE), invisible(data.table(NULL)))
-test(2360.7, tables(env = xenv_empty), invisible(data.table(NULL)))
+test(2366.6, tables(env = xenv_empty, shallow_search = TRUE), invisible(data.table(NULL)))
+test(2366.7, tables(env = xenv_empty), invisible(data.table(NULL)))
 rm(xenv_empty)

From 2f1925661f76fe9fc560cb292f6d9043865b2b4f Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 7 Feb 2026 05:08:28 +0530
Subject: [PATCH 10/13] feat(2606): update tests and comment

---
 R/tables.R            | 13 +++++++++----
 inst/tests/tests.Rraw | 19 +++++++++----------
 2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/R/tables.R b/R/tables.R
index 83a3555670..890539d7b1 100644
--- a/R/tables.R
+++ b/R/tables.R
@@ -20,7 +20,7 @@ type_size = function(DT) {
 
 tables = function(mb=type_size, order.col="NAME", width=80L,
                   env=parent.frame(), silent=FALSE, index=FALSE,
-                  shallow_search=FALSE)
+                  depth=0L)
 {
   # Prints name, size and colnames of all data.tables in the calling environment by default
   mb_name = as.character(substitute(mb))
@@ -31,7 +31,7 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
 
   info = NULL
   # we check if shallow_search is requested and add found tables to w
-  if (shallow_search) {
+  if (depth == 1L) {
     is_list = vapply_1b(obj, is.list)
     is_df = vapply_1b(obj, is.data.frame)
     is_dt = vapply_1b(obj, is.data.table)
@@ -90,14 +90,19 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
       }
     }
   }
-  else {
-    # the original code path when shallow_search=FALSE
+  else if (depth == 0L) {
+    # if depth is 0
     if (!length(w)) {
       if (!silent) catf("No objects of class data.table exist in %s\n", if (identical(env, .GlobalEnv)) ".GlobalEnv" else format(env))
       return(invisible(data.table(NULL)))
     }
     info = data.table(NAME=names[w], NROW=0L, NCOL=0L, MB=0.0, COLS=list(), KEY=list(), INDICES=list())
   }
+  else {
+    # if depth is greater than 0, we will search for data.tables inside lists
+    # this part is not implemented yet, but the structure of the code would be similar to the shallow_search part
+    stop("depth > 1L is not implemented yet")
+  }
   for (i in seq_along(w)) {  # avoid rbindlist(lapply(DT_names)) in case of a large number of tables
     DT = obj[[w[i]]]
     set(info, i, "NROW", nrow(DT))
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 2afad3f2f9..662ac679e5 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -21516,24 +21516,23 @@ df_dcast = data.frame(a = c("x", "y"), b = 1:2, v = 3:4)
 dt_dcast = data.table(a = c("x", "y"), b = 1:2, v = 3:4)
 test(2365.2, dcast(df_dcast, a ~ b, value.var = "v"), dcast(dt_dcast, a ~ b, value.var = "v"))
 
-#2606 tables() shallow_search finds nested data.tables in lists
+#2606 tables() depth=1 finds nested data.tables in lists
 # creating env so that the names are within it
 xenv2 = new.env()
 xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 xenv2$N = list(a = 1:5)
-setkey(xenv2$M$b, a)
+test(2366.1, tables(env = xenv2, depth = 1)[, .(NAME, NROW, NCOL)], data.table(...))
 setindex(xenv2$M$b, b)
-test(2366.1, tables(env = xenv2, shallow_search = TRUE)$NAME, c("DT", "L[[1]]", "L[[2]]", "M$b"))
-test(2366.2, tables(env = xenv2, shallow_search = TRUE)$NROW, c(1L, 3L, 4L, 3L))
-test(2366.3, tables(env = xenv2, shallow_search = TRUE)$NCOL, c(1L, 2L, 2L, 2L))
-test(2366.4, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
-test(2366.5, tables(env = xenv2, shallow_search = TRUE, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
+test(2366.2, tables(env = xenv2, depth = 1, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
+setkey(xenv2$M$b, a)
+test(2366.3, tables(env = xenv2, depth = 1, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
+test(2366.4, expect_error(tables(env = xenv2, depth = 2L), "depth > 1L is not implemented yet"))
 rm(xenv2)
 
-# no data.table test
+# no data.table test and depth >1 test
 xenv_empty = new.env()
-test(2366.6, tables(env = xenv_empty, shallow_search = TRUE), invisible(data.table(NULL)))
-test(2366.7, tables(env = xenv_empty), invisible(data.table(NULL)))
+test(2366.5, tables(env = xenv_empty, depth = 1), invisible(data.table(NULL)))
+test(2366.6, tables(env = xenv_empty), invisible(data.table(NULL)))
 rm(xenv_empty)

From afd197a0cf81b63f591f4929a7f1ae81b0a09797 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 7 Feb 2026 05:15:01 +0530
Subject: [PATCH 11/13] feat(2606): add the dt to test 2366.1

---
 inst/tests/tests.Rraw | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 662ac679e5..db94f2afc6 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -21523,12 +21523,17 @@ xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 xenv2$N = list(a = 1:5)
-test(2366.1, tables(env = xenv2, depth = 1)[, .(NAME, NROW, NCOL)], data.table(...))
+test(2366.1, tables(env = xenv2, depth = 1)[, .(NAME, NROW, NCOL)], 
+  data.table(
+    NAME = c("DT", "L[[1]]", "L[[2]]", "M$b"),
+    NROW = c(1L, 3L, 4L, 3L),
+    NCOL = c(1L, 2L, 2L, 2L)
+))
 setindex(xenv2$M$b, b)
 test(2366.2, tables(env = xenv2, depth = 1, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
 setkey(xenv2$M$b, a)
 test(2366.3, tables(env = xenv2, depth = 1, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
-test(2366.4, expect_error(tables(env = xenv2, depth = 2L), "depth > 1L is not implemented yet"))
+test(2366.4, tryCatch(tables(env = xenv2, depth = 2L), error = function(e) e$message), "depth > 1L is not implemented yet")
 rm(xenv2)
 
 # no data.table test and depth >1 test

From b591887df29c00b2bac6d0355d9a3d2586aa9c95 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 7 Feb 2026 05:21:01 +0530
Subject: [PATCH 12/13] feat(2606): updated comments and doc from shallow
 search to depth arg

---
 NEWS.md               | 2 +-
 R/tables.R            | 5 ++---
 inst/tests/tests.Rraw | 8 ++++----
 man/tables.Rd         | 4 ++--
 4 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index f782e8de3b..e951909409 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -28,7 +28,7 @@
 
 4. `dcast()` and `melt()` "just work" when passed a data.frame, not just data.tables, with no need for coercion, [#7614](https://github.com/Rdatatable/data.table/issues/7614). Thanks @MichaelChirico for the suggestion and @manmita for the PR. Note that to avoid potential conflicts with {reshape2}'s data.frame methods, we do the dispatch to the data.table method manually.
 
-5. `tables()` can now optionally report `data.table` objects stored one level deep inside list objects when `depth=1`, [#2606](https://github.com/Rdatatable/data.table/issues/2606). Thanks @MichaelChirico for the report and @manmita for the PR
+5. `tables()` can now optionally report `data.table` objects stored one level deep inside list objects when `depth=1L`, [#2606](https://github.com/Rdatatable/data.table/issues/2606). Thanks @MichaelChirico for the report and @manmita for the PR
 
 ### BUG FIXES
 
diff --git a/R/tables.R b/R/tables.R
index 890539d7b1..5ed94ee634 100644
--- a/R/tables.R
+++ b/R/tables.R
@@ -30,7 +30,7 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
   w = which(vapply_1b(obj, is.data.table))
 
   info = NULL
-  # we check if shallow_search is requested and add found tables to w
+  # we check if depth=1L is requested and add found tables to w
   if (depth == 1L) {
     is_list = vapply_1b(obj, is.list)
     is_df = vapply_1b(obj, is.data.frame)
@@ -99,8 +99,7 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
     info = data.table(NAME=names[w], NROW=0L, NCOL=0L, MB=0.0, COLS=list(), KEY=list(), INDICES=list())
   }
   else {
-    # if depth is greater than 0, we will search for data.tables inside lists
-    # this part is not implemented yet, but the structure of the code would be similar to the shallow_search part
+    # for depth greater than 1L,recursion is not implemented yet
     stop("depth > 1L is not implemented yet")
   }
   for (i in seq_along(w)) {  # avoid rbindlist(lapply(DT_names)) in case of a large number of tables
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index db94f2afc6..01747a63a4 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -21523,21 +21523,21 @@ xenv2$DT = data.table(a = 1L)
 xenv2$L = list(data.table(a = 1, b = 4:6), data.table(a = 2, b = 7:10))
 xenv2$M = list(b = data.table(a = 1, b = 4:6), a = 1:5)
 xenv2$N = list(a = 1:5)
-test(2366.1, tables(env = xenv2, depth = 1)[, .(NAME, NROW, NCOL)], 
+test(2366.1, tables(env = xenv2, depth = 1L)[, .(NAME, NROW, NCOL)], 
   data.table(
     NAME = c("DT", "L[[1]]", "L[[2]]", "M$b"),
     NROW = c(1L, 3L, 4L, 3L),
     NCOL = c(1L, 2L, 2L, 2L)
 ))
 setindex(xenv2$M$b, b)
-test(2366.2, tables(env = xenv2, depth = 1, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
+test(2366.2, tables(env = xenv2, depth = 1L, index = TRUE)$INDICES, list(NULL, NULL, NULL, "b"))
 setkey(xenv2$M$b, a)
-test(2366.3, tables(env = xenv2, depth = 1, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
+test(2366.3, tables(env = xenv2, depth = 1L, index = TRUE)$KEY, list(NULL, NULL, NULL, "a"))
 test(2366.4, tryCatch(tables(env = xenv2, depth = 2L), error = function(e) e$message), "depth > 1L is not implemented yet")
 rm(xenv2)
 
 # no data.table test and depth >1 test
 xenv_empty = new.env()
-test(2366.5, tables(env = xenv_empty, depth = 1), invisible(data.table(NULL)))
+test(2366.5, tables(env = xenv_empty, depth = 1L), invisible(data.table(NULL)))
 test(2366.6, tables(env = xenv_empty), invisible(data.table(NULL)))
 rm(xenv_empty)
diff --git a/man/tables.Rd b/man/tables.Rd
index 576455d441..437d53e1aa 100644
--- a/man/tables.Rd
+++ b/man/tables.Rd
@@ -6,7 +6,7 @@
 }
 \usage{
 tables(mb=type_size, order.col="NAME", width=80,
-       env=parent.frame(), silent=FALSE, index=FALSE, shallow_search=FALSE)
+       env=parent.frame(), silent=FALSE, index=FALSE, depth=0L)
 }
 \arguments{
   \item{mb}{ a function which accepts a \code{data.table} and returns its size in bytes. By default, \code{type_size} (same as \code{TRUE}) provides a fast lower bound by excluding the size of character strings in R's global cache (which may be shared) and excluding the size of list column items (which also may be shared). A column \code{"MB"} is included in the output unless \code{FALSE} or \code{NULL}. }
@@ -15,7 +15,7 @@ tables(mb=type_size, order.col="NAME", width=80,
   \item{env}{ An \code{environment}, typically the \code{.GlobalEnv} by default, see Details. }
   \item{silent}{ \code{logical}; should the output be printed? }
   \item{index}{ \code{logical}; if \code{TRUE}, the column \code{INDICES} is added to indicate the indices assorted with each object, see \code{\link{indices}}. }
-  \item{shallow_search}{\code{logical}; if \code{TRUE}, searches for \code{data.table} objects inside top-level lists}
+  \item{depth}{\code{integer}; if \code{1L}, searches for \code{data.table} objects inside top-level lists. If depth = 0L it accepts data.table and Values greater than \code{1L} are not implemented yet.}
 }
 \details{
 Usually \code{tables()} is executed at the prompt, where \code{parent.frame()} returns \code{.GlobalEnv}. \code{tables()} may also be useful inside functions where \code{parent.frame()} is the local scope of the function; in such a scenario, simply set it to \code{.GlobalEnv} to get the same behaviour as at prompt.

From 866820a59c75674d939414c6a21a71327699b438 Mon Sep 17 00:00:00 2001
From: manmita <das.manmita12@gmail.com>
Date: Sat, 7 Feb 2026 05:24:45 +0530
Subject: [PATCH 13/13] feat(2606): add call. to stop

---
 R/tables.R | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/R/tables.R b/R/tables.R
index 5ed94ee634..66f0b1819e 100644
--- a/R/tables.R
+++ b/R/tables.R
@@ -100,7 +100,7 @@ tables = function(mb=type_size, order.col="NAME", width=80L,
   }
   else {
     # for depth greater than 1L,recursion is not implemented yet
-    stop("depth > 1L is not implemented yet")
+    stop("depth > 1L is not implemented yet", call. = FALSE)
   }
   for (i in seq_along(w)) {  # avoid rbindlist(lapply(DT_names)) in case of a large number of tables
     DT = obj[[w[i]]]